Hina Arif Tiwari

Interests

Teaching

Body MRI

Research

US MRI Fusion imaging

Courses

Scholarly Contributions

Books

• Larson, M., Witte, R., & Arif Tiwari, H. (2021). An Introduction to non-ionizing radiation. Chapter Title- Ultrasound and Human Body Safety.

Chapters

• Situ-lacasse, E., Situ-lacasse, E., Javedani, P., Devis, P., Devis, P., Arif Tiwari, H., & Arif-tiwari, H. (2020). Ultrasound-Guided Percutaneous Drainage Procedures. In ACR Appropriateness Criteria® acute pancreatitis. Springer, Cham. doi:10.1007/978-3-030-28267-7_11
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  Ultrasound-guided procedures, especially those that are for needle guidance, are all based on the learned skill of being able to track the needle tip the entire time, while it is in the patient under ultrasound imaging. By learning this critical skill, the physician should feel confident in the successful completion of both simple and more complicated, invasive procedures. Ultrasound-guided percutaneous drainage or aspiration of abnormal fluid collections is becoming standard of care in current clinical practice. Ultrasound guidance has led to reduced morbidity and mortality and decrease in length of stay and healthcare costs. Ultrasound-guided percutaneous drainage is minimally invasive and relatively inexpensive and has several advantages over CT including real-time guidance and lack of radiation.
• Arif Tiwari, H., & Situ-LaCasse, E. (2019). Ultrasound-Guided Percutaneous Drainage Procedures. In The Ultimate Guide to Point-of-Care Ultrasound-Guided Procedures. Springer Nature.
• Arif Tiwari, H., Devis, P., Kalb, B., & Martin, D. (2019). Ultrasound guided drainage procedures. In The Ultimate Guide to Point-of-Care Ultrasound-Guided Procedures. 1st edition 2017.. Springer.
• Arif Tiwari, H., Kalb, B., Semelka, R., & Martin, D. (2017). Imaging the Kidneys. In NFK's Primer on Kidney Diseases, 7th edition. Elsevier.
• Costello, J., Arif Tiwari, H., Kalb, B., & Martin, D. (2017). Ultrasound. In An Introduction to Medical Physics, 1st edition. 2017.. Springer.
• Arif Tiwari, H., Kalb, B., Semelka, R., & Martin, D. (2013). Imaging the Kidneys. In NFK's Primer on Kidney Diseases, 6th edition. Elsevier.

Journals/Publications

• Arif Tiwari, H. (2020). Incidence and Predictors of Brain Metastasis in Colorectal Cancer Patients. Diseases of Colon and rectum. Unknown.
• Arif Tiwari, H. (2020). Part 1: Consensus Definitions and Interpretation Templates for Ultrasound Imaging of Evacuatory Pelvic Floor Disorders.. Proceedings of the Consensus Meeting of the Pelvic Floor Consortium of the American Society of Colon and Rectal Surgeons (ASCRS), the Society of Abdominal Radiology (ACR), the American Urogynecologic Society (AUGS), the International Urogynecological Association (IUGA) and the Society of Gynecological Surgeons (SGS)..
• Arif Tiwari, H. (2021). ACR Appropriateness Criteria® Abnormal Liver Function Tests. Expert Panel on Gastrointestinal Imaging.. J Am Coll Radiol.
• Arif Tiwari, H. (2021). Evaluating Intimal Thickness in Healthy Volunteers Using the Vevo 2100. Unknown.
• Arif Tiwari, H. (2021). Evaluation of Diagnostic performance of novel real time MR-directed US-guided (MRdUSg) Prostate Biopsy method. Unknown.
• Arif Tiwari, H. (2021). MR Virtual Biopsy of Solid Renal Masses. Magnetic Resonance Imaging.
• Arif Tiwari, H. (2021). MR imaging in Ovarian Torsion. Unknown.
• Arif Tiwari, H. (2021). Performance of non-contrast magnetic resonance pulmonary angiogram to exclude pulmonary thromboembolism in pregnant patients. Unknown.
• Arif Tiwari, H., & Bozdogan, E. (2021). Post-operative Multiparameteric MR Imaging using PIRADS score following Holimum Laser Enucleation of Prostate gland. Unknown.
• Arif Tiwari, H., & Gudi, H. (2021). Neoadjauvant Chemoradiotherapy response in rectal cancer on Multiparameteric MR imaging. Unknown.
• Arif Tiwari, H., & Jayagurunathan, U. (2021). Magnetic Resonance Imaging of Steatosis Hepatocellular carcinoma. Unknown.
• Arif Tiwari, H., & Kambadakone, A. (2021). Imaging in FGFR2 Intrahepatic Cholangiocarcinoma. Unknown.
• Arif Tiwari, H., & Khan, A. (2021). Magnetic Resonance Imaging of Non-Occlusive Hepatic Infarction Associated with Diabetic Ketoacidosis.. Journal of open case reports.
• Arif Tiwari, H., & Larson, M. (2021). Evaluation of post Y-90 radioembolization changes in Hepatocellular Carcinoma on diffusion and perfusion MR imaging. Unknown.
• Arif Tiwari, H., Sadovnikov, I., & Anthony, M. (2021). Tale of the traveling Gallstone through MR imaging. Unknown.
• Childs, D. D., Lalwani, N., Craven, T., Arif, H., Morgan, M., Anderson, M., & Fulcher, A. (2024). A meta-analysis of the performance of ultrasound, hepatobiliary scintigraphy, CT and MRI in the diagnosis of acute cholecystitis. Abdominal radiology (New York), 49(2), 384-398.
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  To evaluate the recently reported relative diagnostic accuracy of US, CT, MRI, and cholescintigraphy for diagnosing acute cholecystitis.
• Chu, L., Wang, J., Kambadakone, A., He, J., Narang, A., Laheru, D., Arif Tiwari, H., Zins, M., Fishman, E., Tamm, E., & Zaheer, A. (2021). Postoperative Surveillance of Pancreatic Ductal Adenocarcinoma Recurrence: Practice Pattern on Standardized Imaging and Reporting from the Society of Abdominal Radiology Pancreatic Ductal Adenocarcinoma Disease Focus Panel. Abdominal Imaging.
• El Homsi, M., Alkhasawneh, A., Arif-Tiwari, H., Czeyda-Pommersheim, F., Khasawneh, H., Kierans, A. S., Paspulati, R. M., & Singh, C. (2024). Classification of intrahepatic cholangiocarcinoma. Abdominal radiology (New York).
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  Cholangiocarcinoma is a heterogenous malignancy with various classifications based on location, morphological features, histological features, and actionable genetic mutations. Intrahepatic cholangiocarcinoma (ICC), which arises in and proximal to second order bile ducts, is the second most common primary liver malignancy after hepatocellular carcinoma. In this review, we will discuss ICC risk factors, precursor lesions, various growth, anatomic, morphologic, and histologic classifications, rare variants, and differential diagnoses.
• Eshghi, N., Cragun, J., & Arif Tiwari, H. (2020). MR imaging of Ectopic and Molar Pregnancy. Diagn Interv Radiol.
• Goyal, U., Cheung, M., Suszko, J., Laughlin, B., Kim, Y., Askam, J., Arif Tiwari, H., Slane, B., Gordon, J., & Stea, B. (2021). Electronic brachytherapy for treatment of non-melanoma skin cancers: clinical results and Toxicities. Journal of Contemporary Brachytherapy.
• Kalb, B. T., Arif Tiwari, H., Martin, D. R., Saranathan, M., & Bisla, J. (2018). Imaging Evaluation of the Kidneys in Patients with Reduced Kidney Function: Noncontrast Techniques verus Contrast-Enhanced Techniques. Magnetic Resonance Clinics of North America.
• Khasawneh, H., O'Brien, C., Czeyda-Pommersheim, F., Qayyum, A., Miller, F. H., Arif Tiwari, H., Paspulati, R. M., & Kierans, A. S. (2024). Beyond cholangiocarcinoma: imaging features of mimicking pathologies in the biliary tract. Abdominal radiology (New York).
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  Cholangiocarcinoma (CCA) is the second most common primary malignancy of the hepatobiliary system and presents as a heterogeneous disease with three distinct morphological subtypes: mass-forming, periductal-infiltrating, and intraductal-growing, each characterized by distinguishing imaging features. Accurate diagnosis of CCA is challenging due to the overlap of imaging findings with a broad range of benign and malignant conditions. Therefore, it is essential for radiologists to recognize these mimickers and offer a reasonable differential diagnosis, as this has a significant impact on patient management. Although histopathological confirmation is often required for a definitive diagnosis, understanding specific imaging characteristics that differentiate CCA from its mimickers is crucial. This article highlights a variety of benign and malignant conditions that resemble CCA on imaging, emphasizing features that enhance diagnostic accuracy in clinical practice.
• Konstantinoff, K. S., Ludwig, D. R., Sharbidre, K., Arif-Tiwari, H., & Itani, M. (2024). Gallbladder and biliary pathology: lessons learned from multidisciplinary conference. Abdominal radiology (New York).
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  The radiologic diagnosis of biliary disease can be challenging due to atypical or delayed presentation, rare or less common entities, and imaging overlap of benign and malignant processes. Establishing a specific diagnosis, when possible, is important to avoid progression of infections to sepsis and multiorgan failure, and for appropriate staging and management in cases of malignancy. Gallstones are the most common biliary disease, and along with stone-related complications, including cholecystitis and choledocholithiasis, constitute the majority of acute biliary pathology. Late and atypical manifestations of acute cholecystitis demonstrate imaging overlap with primary gallbladder cholangiocarcinoma, especially with cases of exuberant inflammatory reaction such as xanthogranulomatous cholecystitis. Additional challenging scenarios related to gallbladder disease, that may be benign or malignant, include adjacent fistulas and lymphadenopathy. Dropped gallstones, especially in atypical locations, may be misdiagnosed as neoplastic. Recurrent cholecystitis after cholecystectomy, whether related to subtotal cholecystectomy or to stumpitis, is another entity that can be confusing to the radiologist with a documented history of cholecystectomy. Inflammatory and autoimmune conditions, such as pseudotumors and IgG4 disease, are a less common but not infrequent cause of diagnostic dilemma. Furthermore, biliary strictures and hepatobiliary cystic lesions can be benign or malignant and could constitute a diagnostic and management challenge. The goal of this manuscript is to present the lessons learned from multidisciplinary conferences on the above entities and suggest tips and pearls to maximize the value of radiologists' contribution to patient management.
• Meshaal, N., Arif Tiwari, H., Jambekar, K., & Ram, R. (2020). Revisiting splenic lesions- an imaging review of the common and uncommon splenic pathology. Journal of Gastrointestinal and Abdominal Radiology.
• Nair, R. T., Chan, A., Morgan, M. A., Itani, M., Ganeshan, D., Arif-Tiwari, H., El-Haddad, E., Sabujan, A., & Dawkins, A. A. (2024). Biliary complications of surgical procedures: what the radiologist needs to know. Abdominal radiology (New York).
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  Post-surgical biliary complications increase morbidity, mortality, and healthcare utilization. Early detection and management of biliary complications is thus of great clinical importance. Even though the overall risk for biliary complications is low after laparoscopic cholecystectomy, post-cholecystectomy biliary complications are frequently encountered in clinical practice as laparoscopic cholecystectomy is the most common surgical procedure performed in the United States. Other surgical procedures fraught with biliary complications include liver transplantation, pancreaticoduodenectomy, hepatic resection, and gastric surgeries.The clinical presentation of biliary complications is variable; imaging, thus, plays a vital role in diagnosis and management. Biliary leak (BL) and stricture are the most common biliary complications. Although Ultrasound (US) and Computed Tomography (CT) can detect collections and free fluid due to a BL, imaging confirmation of a biliary origin requires the use of a Hepatobiliary Iminodiacetic Acid (HIDA) scan or Magnetic Resonance Cholangiopancreatography (MRCP) with hepatocyte-specific contrast agent. Biliary strictures can present months to years after the original injury; the attendant biliary dilation is well seen on cross-sectional modalities. MRCP plays a crucial role in excluding features suggestive of a malignant etiology and establishing the type and anatomical extent of the injury for therapeutic planning. Radiologists thus play a vital role in detecting and managing biliary complications. This article provides an overview of the applied anatomy, clinical presentation, imaging, and therapeutic considerations of biliary complications after surgical procedures.
• Sadovnikov, I., Anthony, M., & Arif Tiwari, H. (2020). Bouveret’s syndrome: Case report with review of the literature. Journal of Clinical Imaging.
• Taneja, A., & Arif Tiwari, H. (2021). Magnetic Resonance Imaging of Infiltrative Hepatocellular Carcinoma- Characterization of Imaging Features and Tumor Conspicuity. Unknown.
• Valencia, C. I., Wightman, P., Morrill, K. E., Hsu, C. H., Arif-Tiwari, H., Kauffman, E., Gachupin, F. C., Chipollini, J., Lee, B. R., Garcia, D. O., & Batai, K. (2024). Neighborhood social vulnerability and disparities in time to kidney cancer surgical treatment and survival in Arizona. Cancer medicine, 13(3), e7007.
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  Hispanics and American Indians (AI) have high kidney cancer incidence and mortality rates in Arizona. This study assessed: (1) whether racial and ethnic minority patients and patients from neighborhoods with high social vulnerability index (SVI) experience a longer time to surgery after clinical diagnosis, and (2) whether time to surgery, race and ethnicity, and SVI are associated with upstaging to pT3/pT4, disease-free survival (DFS), and overall survival (OS).
• VanBuren, W., Feldman, M., Shenoy-Bhangle, A. S., Sakala, M. D., Young, S., Chamie, L. P., Giudice, L., Hindman, N. M., Tong, A., Rabban, J. T., Yano, M., Kilcoyne, A., Dave, H. D., Poder, L., Kho, R. M., Burnett, T. L., Khan, Z., King, C., Shen, L., , Colak, C., et al. (2024). Radiology State-of-the-art Review: Endometriosis Imaging Interpretation and Reporting. Radiology, 312(3), e233482.
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  Endometriosis is a common condition impacting approximately 190 million individuals and up to 50% of women with infertility globally. The disease is characterized by endometrial-like tissue located outside of the uterine corpus, which causes cyclical hemorrhage, inflammation, and fibrosis. Based on clinical suspicion or findings at routine transvaginal pelvic US or other prior imaging, dedicated imaging for endometriosis may be warranted with MRI or advanced transvaginal US. Deep endometriosis (DE) in the pelvis includes evaluation for stromal and fibrotic components and architectural distortion resulting from fibrosis and tethering. It is a disease requiring a compartment-based, pattern-recognition approach. MRI has the benefit of global assessment of the pelvis and is effective in assessing for features of malignancy and for evaluating extrapelvic locations. Transvaginal US has the advantage of dynamic maneuvers to assess for adhesions and may achieve higher spatial resolution for assessing the depth of bowel wall invasion. T1-weighted MRI evaluation increases the specificity of diagnosis by identifying hemorrhagic components, but the presence of T1 signal hyperintensity is not essential for diagnosing DE. Endometriosis is a disease with a broad spectrum; understanding the mild through advanced manifestations, including malignancy evaluation, is within the scope and breadth of radiologists' interpretation.
• , E. P., Arif-Tiwari, H., Porter, K. K., Kamel, I. R., Bashir, M. R., Fung, A., Kaplan, D. E., McGuire, B. M., Russo, G. K., Smith, E. N., Solnes, L. B., Thakrar, K. H., Vij, A., Wahab, S. A., Wardrop, R. M., Zaheer, A., & Carucci, L. R. (2023). ACR Appropriateness Criteria® Abnormal Liver Function Tests. Journal of the American College of Radiology : JACR, 20(11S), S302-S314.
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  Liver function tests are commonly obtained in symptomatic and asymptomatic patients. Various overlapping lab patterns can be seen due to derangement of hepatocytes and bile ducts function. Imaging tests are pursued to identify underlying etiology and guide management based on the lab results. Liver function tests may reveal mild, moderate, or severe hepatocellular predominance and can be seen in alcoholic and nonalcoholic liver disease, acute hepatitis, and acute liver injury due to other causes. Cholestatic pattern with elevated alkaline phosphatase with or without elevated γ-glutamyl transpeptidase can be seen with various causes of obstructive biliopathy. Acute or subacute cholestasis with conjugated or unconjugated hyperbilirubinemia can be seen due to prehepatic, intrahepatic, or posthepatic causes. We discuss the initial and complementary imaging modalities to be used in clinical scenarios presenting with abnormal liver function tests. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.
• Alshiek, J., Murad-Regadas, S. M., Mellgren, A., Glanc, P., Khatri, G., Quiroz, L. H., Weinstein, M. M., Rostaminia, G., Oliveira, L., Arif-Tiwari, H., Ferrari, L., Bordeianou, L. G., Shobeiri, S. A., & , M. o. (2023). Consensus Definitions and Interpretation Templates for Dynamic Ultrasound Imaging of Defecatory Pelvic Floor Disorders: Proceedings of the Consensus Meeting of the Pelvic Floor Disorders Consortium of the American Society of Colon and Rectal Surgeons, the Society of Abdominal Radiology, the International Continence Society, the American Urogynecologic Society, the International Urogynecological Association, and the Society of Gynecologic Surgeons. Diseases of the colon and rectum, 66(2), 200-216.
• Alshiek, J., Murad-Regadas, S. M., Mellgren, A., Glanc, P., Khatri, G., Quiroz, L. H., Weinstein, M. M., Rostaminia, G., Oliveira, L., Arif-Tiwari, H., Ferrari, L., Bordeianou, L., Shobeiri, S. A., & , M. o. (2023). Consensus Definitions and Interpretation Templates for Dynamic Ultrasound Imaging of Defecatory Pelvic Floor Disorders. Urogynecology (Philadelphia, Pa.), 29(3), 327-343.
• Alshiek, J., Murad-Regadas, S. M., Mellgren, A., Glanc, P., Khatri, G., Quiroz, L. H., Weinstein, M. M., Rostaminia, G., Oliveira, L., Arif-Tiwari, H., Ferrari, L., Bordeianou, L., Shobeiri, S. A., & , M. o. (2023). Consensus definitions and interpretation templates for dynamic ultrasound imaging of defecatory pelvic floor disorders : Proceedings of the consensus meeting of the pelvic floor disorders consortium of the american society of colon and rectal surgeons, the society of abdominal radiology, the international continence society, the American urogynecologic society, the international urogynecological association, and the society of gynecologic surgeons. International urogynecology journal, 34(3), 603-619.
• Barr, C., Arif Tiwari, H., & Thompson, W. (2023). Acute Cholecystitis, Chronic Cholecystitis, and Associated Complications: Findings on Imaging. Contemporary Diagnostic Radiology, 9(46), 1-7. doi:10.1097/01.CDR.0000926648.83978.cb
• Chartier, S., & Arif-Tiwari, H. (2023). MR Virtual Biopsy of Solid Renal Masses: An Algorithmic Approach. Cancers, 15(10).
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  Between 1983 and 2002, the incidence of solid renal tumors increased from 7.1 to 10.8 cases per 100,000. This is in large part due to the increase in the volume of ultrasound and cross-sectional imaging, although a majority of solid renal tumors are still found incidentally. Ultrasound and computed tomography (CT) have been the mainstay of renal mass screening and diagnosis but recent advances in magnetic resonance (MR) technology have made this the optimal choice when diagnosing and staging renal tumors. Our purpose in writing this review is to survey the modern MR imaging approach to benign and malignant solid renal tumors, consolidate the various imaging findings into an easy-to-read reference, and provide an imaging-based, algorithmic approach to renal mass characterization for clinicians. MR is at the forefront of renal mass characterization, surpassing ultrasound and CT in its ability to describe multiple tissue parameters and predict tumor biology. Cutting-edge MR protocols and the integration of diagnostic algorithms can improve patient outcomes, allowing the imager to narrow the differential and better guide oncologic and surgical management.
• Chu, L. C., Wang, Z. J., Kambadakone, A., Hecht, E. M., He, J., Narang, A. K., Laheru, D. A., Arif-Tiwari, H., Bhosale, P., Bolan, C. W., Brook, O. R., Bezuidenhout, A. F., Do, R. K., Galgano, S. J., Goenka, A. H., Guimaraes, A. R., Hough, D. M., Kulkarni, N., Le, O., , Luk, L., et al. (2023). Postoperative surveillance of pancreatic ductal adenocarcinoma (PDAC) recurrence: practice pattern on standardized imaging and reporting from the society of abdominal radiology disease focus panel on PDAC. Abdominal radiology (New York), 48(1), 318-339.
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  Surgical resection is the only potential curative treatment for patients with pancreatic ductal adenocarcinoma (PDAC), but unfortunately most patients recur within 5 years of surgery. This article aims to assess the practice patterns across major academic institutions and develop consensus recommendations for postoperative imaging and interpretation in patients with PDAC.
• Duhancioglu, G., Arif-Tiwari, H., Natali, S., Reynolds, C., Lalwani, N., & Fulcher, A. (2023). Traveling gallstones: review of MR imaging and surgical pathology features of gallstone disease and its complications in the gallbladder and beyond. Abdominal radiology (New York).
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  Gallstone-related disease comprises a spectrum of conditions resulting from biliary stone formation, leading to obstruction and inflammatory complications. These can significantly impact patient quality of life and carry high morbidity if not accurately detected. Appropriate imaging is essential for evaluating the extent of gallstone disease and assuring appropriate clinical management. Magnetic Resonance Imaging (MRI) techniques (including Magnetic Resonance Cholangiopancreatography (MRCP) are increasingly used for diagnosis of gallstone disease and its complications and provide high contrast resolution and facilitate tissue-level assessment of gallstone disease processes. In this review we seek to delve deep into the spectrum of MR imaging in diagnose of gallstone-related disease within the gallbladder and complications related to migration of the gallstones to the gall bladder neck or cystic duct, common hepatic duct or bile duct (choledocholithiasis) and beyond, including gallstone pancreatitis, gallstone ileus, Bouveret syndrome, and dropped gallstones, by offering key examples from our practice. Furthermore, we will specifically highlight the crucial role of MRI and MRCP for enhancing diagnostic accuracy and improving patient outcomes in gallstone-related disease and showcase relevant surgical pathology specimens of various gallstone related complications.
• Khot, R., Morgan, M. A., Nair, R. T., Ludwig, D. R., Arif-Tiwari, H., Bhati, C. S., & Itani, M. (2023). Radiologic findings of biliary complications post liver transplantation. Abdominal radiology (New York), 48(1), 166-185.
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  Liver transplantation is a potentially curative treatment for patients with acute liver failure, end-stage liver disease, and primary hepatic malignancy. Despite tremendous advancements in surgical techniques and immunosuppressive management, there remains a high rate of post-transplant complications, with one of the main complications being biliary complications. In addition to anastomotic leak and stricture, numerous additional biliary complications are encountered, including ischemic cholangiopathy due to the sole arterial supply of the bile ducts, recurrence of primary biliary disease, infections, biliary obstruction from stones, cast, or hemobilia, and less commonly cystic duct remnant mucocele, vanishing duct syndrome, duct discrepancy and kinking, post-transplant lymphoproliferative disorder, retained stent, and ampullary dysfunction. This article presents an overview of biliary anatomy and surgical techniques in liver transplantation, followed by a detailed review of post-transplant biliary complications with their corresponding imaging findings on multiple modalities with emphasis on magnetic resonance imaging and MR cholangiopancreatography.
• Ludwig, D. R., Itani, M., Childs, D. D., Revzin, M. V., Das, K. K., Anderson, M. A., Arif-Tiwari, H., Lockhart, M. E., & Fulcher, A. S. (2023). Biliary Duct Dilatation: Expert Panel Narrative Review. AJR. American journal of roentgenology.
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  Biliary duct dilation is a common incidental finding in practice, but one unlikely to indicate biliary obstruction in the absence of clinical symptoms or elevated liver chemistries. However, the clinical presentation may be nonspecific, and the liver chemistries either unavailable or difficult to interpret. The goal of this article is to review a series of topics fundamental to the management of biliary duct dilation, providing consensus recommendations in a question-and-answer format. We start by covering a basic approach to interpreting liver chemistries, strengths and weaknesses of the biliary imaging modalities, and how and where to measure the extrahepatic bile duct. Next, we define criteria for biliary duct dilation, including patients with prior cholecystectomy and advanced age, and cover when and if biliary duct dilation can be attributed to papillary stenosis or sphincter of Oddi dysfunction. Subsequently, we discuss two conditions in which the duct is pathologically dilated but not obstructed: congenital cystic dilation (i.e., choledochal cyst) and intraductal papillary neoplasm of the bile duct. Finally, we provide guidance on when to recommend obtaining additional imaging or testing such as endoscopic ultrasound or ERCP, and include a discussion of future directions in biliary imaging.
• Manshad, S., Arif Tiwari, H., & Thompson, W. (2023). Gallbladder Beyond Gallstones. Contemporary Diagnostic Radiology, 3(46), 1-7. doi:10.1097/01.CDR.0000911964.22048.94
• Sundaram, K. M., Morgan, M. A., Depetris, J., & Arif-Tiwari, H. (2023). Imaging of benign gallbladder and biliary pathologies in pregnancy. Abdominal radiology (New York), 48(6), 1921-1932.
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  The rising incidence combined with pregnancy-related physiological changes make gallbladder and biliary pathology high on the differential for pregnant patients presenting with right upper abdominal pain. Imaging plays a crucial role in determining surgical versus non-surgical management in pregnant patients with biliary or gallbladder pathology. Ultrasound (first-line) and magnetic resonance with magnetic resonance cholangiopancreatography (second-line) are the imaging techniques of choice in pregnant patients with suspected biliary pathology due to their lack of ionizing radiation. MRI/MRCP offers an excellent non-invasive imaging option, providing detailed anatomical detail without known harmful fetal side effects. This article reviews physiological changes in pregnancy that lead to gallstone and biliary pathology, key imaging findings on US and MRI/MRCP, and management pathways.
• Galgano, S. J., Morani, A. C., Gopireddy, D. R., Sharbidre, K., Bates, D. D., Goenka, A. H., Arif-Tiwari, H., Itani, M., Iravani, A., Javadi, S., Faria, S., Lall, C., Bergsland, E., Verma, S., Francis, I. R., Halperin, D. M., Chatterjee, D., Bhosale, P., & Yano, M. (2022). Pancreatic neuroendocrine neoplasms: a 2022 update for radiologists. Abdominal radiology (New York), 47(12), 3962-3970.
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  Pancreatic neuroendocrine neoplasms (PaNENs) are a unique group of pancreatic neoplasms with a wide range of clinical presentations and behaviors. Given their heterogeneous appearance and increasing detection on cross-sectional imaging, it is essential that radiologists understand the variable presentation and distinctions PaNENs display compared to other pancreatic neoplasms. Additionally, some of these neoplasms may be hormonally functional, and it is imperative that radiologists be aware of the common clinical presentations of hormonally active PaNENs. Knowledge of PaNEN pathology and treatments may influence which imaging modality is optimal for each patient. Each imaging modality used for PaNENs has distinct advantages and disadvantages, particularly in different treatment settings. Thus, the focus of this manuscript is to provide an update for the radiologist on PaNEN pathology, imaging, and treatments.
• Larson, K., Russ, A., Arif-Tiwari, H., Mahadevan, D., Elliott, A., Bhattacharyya, A., & Babiker, H. (2022). Pembrolizumab Achieves a Complete Response in an NF-1 Mutated, PD-L1 Positive Malignant Peripheral Nerve Sheath Tumor: A Case Report and Review of the Benchmarks. Journal of immunotherapy (Hagerstown, Md. : 1997).
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  Malignant peripheral nerve sheath tumors (MPNSTs) represent a rare subtype of neural crest cell-derived soft tissue sarcomas (STS). Standard of care therapy comprises surgical resection followed by adjuvant radiation, and most clinical studies have demonstrated finite survival benefit of radiation and chemotherapy. In metastatic disease, palliative chemotherapy provides very limited efficacy. We report a 60-year-old male patient with a primary para vertebral tumor at T7-T8 with lung metastases who recurred after surgical resection and later progressed on epirubicin plus ifosfamide. He was an international patient and referred to the phase 1 clinic. Molecular profiling and immunohistochemistry of the tumor revealed a PD-L1 expression of 70% (2+) and pathogenic genetic alterations by next-generation sequencing in ARID1A, CDKN2A, KMT2A, NF1, and TP53. Immune checkpoint therapy (ICT) with pembrolizumab was commenced, and interval computed tomography revealed a complete remission by cycle 6. Randomized clinical trials illustrate that ICTs such as anti-PD-1 and anti-CTLA4 monoclonal antibodies in STS cohorts display low or modest response rates by variable PD-L1 expression. This and 3 other case reports of disparate PD-L1 expression demonstrate complete responses in PD-L1 positive MPNSTs treated with ICT. These case reports necessitate further study of ICT in neural crest cell subtype of STS.
• Sundararajan, S., Arif Tiwari, H., Stratton, D., Curiel, C. N., Cui, H., & Roe, D. (2022). A single arm phase 2 study of talimogene laherparepvec in patients with low-risk invasive cutaneous squamous cell cancer. interim analysis.. Journal of Clinical Oncology, 40(16_suppl), e21583-e21583. doi:10.1200/jco.2022.40.16_suppl.e21583
• Yano, M., Verma, S., Sharbidre, K., Morani, A. C., Lall, C., Javadi, S., Itani, M., Iravani, A., Halperin, D. M., Gopireddy, D. R., Goenka, A. H., Galgano, S. J., Francis, I. R., Faria, S., Chatterjee, D., Bhosale, P., Bergsland, E., Bates, D. D., & Arif-tiwari, H. (2022). Pancreatic neuroendocrine neoplasms: a 2022 update for radiologists. Abdominal Radiology. doi:10.1007/s00261-022-03466-9
• , ., & , . (2021). Endometriosis DFP report. Abdominal radiology (New York), 46(2), 409-410.
• , E. P., Vij, A., Zaheer, A., Kamel, I. R., Porter, K. K., Arif-Tiwari, H., Bashir, M. R., Fung, A., Goldstein, A., Herr, K. D., Kamaya, A., Kobi, M., Landler, M. P., Russo, G. K., Thakrar, K. H., Turturro, M. A., Wahab, S. A., Wardrop, R. M., Wright, C. L., , Yang, X., et al. (2021). ACR Appropriateness Criteria® Epigastric Pain. Journal of the American College of Radiology : JACR, 18(11S), S330-S339.
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  Epigastric pain can have multiple etiologies including myocardial infarction, pancreatitis, acute aortic syndromes, gastroesophageal reflux disease, esophagitis, peptic ulcer disease, gastritis, duodenal ulcer disease, gastric cancer, and hiatal hernia. This document focuses on the scenarios in which epigastric pain is accompanied by symptoms such as heartburn, regurgitation, dysphagia, nausea, vomiting, and hematemesis, which raise suspicion for gastroesophageal reflux disease, esophagitis, peptic ulcer disease, gastritis, duodenal ulcer disease, gastric cancer, or hiatal hernia. Although endoscopy may be the test of choice for diagnosing these entities, patients may present with nonspecific or overlapping symptoms, necessitating the use of imaging prior to or instead of endoscopy. The utility of fluoroscopic imaging, CT, MRI, and FDG-PET for these indications are discussed. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
• Arif Tiwari, H. (2021). ACR Appropriateness Criteria® Epigastric Pain. Expert Panel on Gastrointestinal Imaging. J Am Coll Radiol..
• Arif Tiwari, H. (2021). Pancreatic cancer DFP report. Abdominal radiology (New York), 46(2), 425-426.
• Arif Tiwari, H. (2021). Pelvic floor DFP report. Abdominal radiology (New York), 46(2), 420.
• Arif-Tiwari, H., Twiss, C. O., Lin, F. C., Funk, J. T., Vedantham, S., Martin, D. R., & Kalb, B. T. (2021). Improved Detection of Pelvic Organ Prolapse: Comparative Utility of Defecography Phase Sequence to Nondefecography Valsalva Maneuvers in Dynamic Pelvic Floor Magnetic Resonance Imaging. Current problems in diagnostic radiology, 48(4), 342-347.
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  To evaluate the utility of a defecography phase (DP) sequence in dynamic pelvic floor MRI (DPMRI), in comparison to DPMRI utilizing only non-defecography Valsalva maneuvers (VM).
• Dohogne, B., Arif-Tiwari, H., Bracamonte, E., & Babiker, H. M. (2021). Exceptional response to cyclophosphamide and dexamethasone in a patient with metastatic castrate-resistant prostate cancer and RB1 mutation. Anti-cancer drugs, 32(3), 337-343.
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  Rates of prostate cancer relapsing from anti-androgen therapies are increasing in the United States and worldwide. It has been suggested that this is caused by variant and altered lineage marker expression within the tumor, allowing for lineage plasticity that then facilitates therapeutic resistance. The genomic landscape of castrate-resistant prostate cancer has been well-defined with the advent of next-generation sequencing, but the clinical applications of these findings as measured by patient outcomes remains poorly understood. Here, we report on a patient with recurrent, metastatic castrate-resistant prostate cancer and identified RB1 mutation with progressive symptomatology, who was treated with cyclophosphamide and dexamethasone after other standard treatment regimens failed. After completing 2 years of treatment, he experienced complete resolution of his symptoms. Disease remission was confirmed on multiple imaging modalities and through serial measurements of prostate-specific antigen levels that showed a reduction of 99%. Our patient's case supports ongoing research that genetic profiling can help elucidate key biological and molecular tumor components, which can then inform targeted, individualized treatment approaches in the management of recurrent, castrate-resistant prostate cancer.
• Gimber, L. H., Melville, D. M., Klauser, A. S., Witte, R. S., Arif-Tiwari, H., & Taljanovic, M. S. (2021). Artifacts at Musculoskeletal US: Resident and Fellow Education Feature. Radiographics : a review publication of the Radiological Society of North America, Inc, 36(2), 479-80.
• Goyal, U., Cheung, M. K., Suszko, J., Laughlin, B., Kim, Y., Askam, J., Arif-Tiwari, H., Slane, B., Gordon, J., & Stea, B. (2021). Electronic brachytherapy for treatment of non-melanoma skin cancers: clinical results and toxicities. Journal of contemporary brachytherapy, 13(5), 497-503.
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  Although surgical approaches are standard for most non-melanomatous skin cancers, some patients are not candidates due to medical co-morbidities or functional or cosmetic or lesion location. High-dose-rate electronic brachytherapy (HDR-EBT) may be an alternative treatment modality.
• Itani, M., Lalwani, N., Anderson, M. A., Arif-Tiwari, H., Paspulati, R. M., & Shetty, A. S. (2021). Magnetic resonance cholangiopancreatography: pitfalls in interpretation. Abdominal radiology (New York).
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  Magnetic resonance cholangiopancreatography (MRCP) has become a widely accepted noninvasive diagnostic tool in the assessment of pancreatic and biliary disease. MRCP essentially exploits extended T2 relaxation times of slow-moving fluid and delineates the outline of biliary and pancreatic ducts on T2-weighted images. In order to maximize the clinical implication of MRCP, it is of utmost importance for radiologists to optimize the acquisition technique, be aware of patient-related factors and physiologic changes than can affect its performance and interpretation. It is critical to understand the most common artifacts and pitfalls encountered during acquisition and interpretation of MRCP. We provide a general overview of the different pitfalls encountered in MRCP and pearls on how to manage them in real-world practice.
• Kanmaniraja, D., Arif-tiwari, H., Palmer, S. L., Kamath, A., Lewis, S. C., Flusberg, M., Kobi, M., Lockhart, M. E., & Chernyak, V. (2021). MR defecography review.. Abdominal radiology (New York), 46(4), 1334-1350. doi:10.1007/s00261-019-02228-4
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  Pelvic floor dysfunction is a relatively common but often complex condition, presenting with a variety of clinical symptoms, especially when it involves multiple compartments. Clinical exam alone is often inadequate and requires a complementary imaging study. Magnetic resonance defecography (MRD) is an excellent noninvasive diagnostic study with its multiplanar capability, lack of ionizing radiation and excellent soft tissue resolution. It can identify both anatomic and functional abnormalities in the pelvic floor and specifically excels in its ability to simultaneously detect multicompartmental pathology and help with vital pre-operative assessment. This manuscript reviews the relevant anatomical landmarks, describes the optimal technique, highlights an approach to the interpretation of MRD, and provides an overview of the various pelvic floor disorders in the different anatomical compartments.
• Lalwani, N., Bates, D. D., Arif-Tiwari, H., Khandelwal, A., Korngold, E., & Lockhart, M. (2021). Baseline MR Staging of Rectal Cancer: A Practical Approach. Seminars in roentgenology, 56(2), 164-176.
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  As therapeutic options to treat rectal cancers have advanced over the last several decades, MRI has become the standard of care for baseline local tumor and nodal staging of rectal cancers. An understanding of the technique, anatomy, tumor appearance, and elements of staging on MRI is essential to provide prognostic information and to guide neoadjuvant chemoradiation and surgical treatment. We provide a framework for imaging the rectum on MRI followed by a practical case-based approach to interpretation of pre-treatment MRI of the rectum in evaluation of rectal cancers, with examples and illustrations of the range of local tumor (T) stage and nodal (N) disease involvement. This approach can be paired with standardized reporting templates to support clear, accurate and clinically relevant imaging assessment of rectal cancers.
• Malangone, S. A., Patel, H., Kurtin, S. E., Tiwari, H. A., & Elquza, E. (2021). Grand Rounds: Multidisciplinary Management of the Patient With Metastatic Colorectal Adenocarcinoma. Journal of the advanced practitioner in oncology, 6(2), 144-52.
• Marr, K. D., Nagle, R. B., Warfel, N. E., Gard, J. M., Cress, A. E., & Arif-tiwari, H. (2021). Abstract LB233: Cancer cell invasion through a complex and dynamic smooth muscle microenvironment. Cancer Research, 81(13_Supplement), LB233-LB233. doi:10.1158/1538-7445.am2021-lb233
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  Abstract The cancer-prone peripheral zone of the human prostate is a fibromuscular stroma bounded by a laminin-rich smooth muscle capsule. Aggressive tumors traverse the muscle to escape organ confinement, but the determinants of cell migration through this complex and highly elastic environment are not well understood. We modeled smooth muscle invasion using a unique in vivo model to test the role of mechanosensing, laminin-binding integrins (α6β1 and α3β1), collect cells successful in traversing smooth muscle, and identify transcriptomes involved in this complex invasive process. From the DU145 prostate cancer cell line (expressing integrins α3 and α6), we generated homozygous knockouts for genes ITGA6 (α6KO) and ITGA3 (α3KO). We tested for the ability to create 3D invasive cellular networks and measured biophysical features by electric cell-substrate impedance sensing. Muscle invasion was tested in vivo by injecting cells into the intraperitoneal cavity of male NSG mice. The cells colonized the inferior side of the respiratory diaphragm and invaded through to the superior surface after 6 weeks. We analyzed diaphragms by number of invasion sites and average invasion depth. A series of clones were also grown from wild-type, DU145 cells that had completely traversed the diaphragm muscle. Cells expressing integrins α6 and α3 produced 3D invasive networks on laminin-containing Matrigel and invaded into the diaphragm muscle in vivo. α6KO cells did not produce networks or invade muscle. Surprisingly, knockout of α3 increased 3D invasive networks, decreased cell-cell impedance, and altered in vivo muscle invasion. The results suggest that the integrins α6 and α3 are involved in the invasion of prostate cancer cells through a dynamic smooth muscle layer. The mechanosensing integrins are central to a variety of cell signaling programs. To further explore the transcriptional regulators of the muscle invasion process, we isolated RNA from cancer cells colonizing the inferior, superior surface and the intact diaphragm. Whole genome RNAseq revealed 1330 differentially expressed genes (DEGs) between inferior cells and cancer cells within the diaphragm, 788 DEGs between cells on the inferior and superior diaphragm surface, and 241 DEGs between cancer cells within the diaphragm and cells that reached the superior surface (padj =1.3). Ingenuity Pathway Analysis revealed alterations in pathways including prostate cancer signaling, integrin signaling, other known cancer-related processes, and others. Through this in vivo assay we have the unique ability to parse out unexplored patterns of changes that occur in early muscle invasive disease to improve prostate cancer patient selection for curative treatment versus active surveillance. These studies were supported by NCI F30CA247106, P30CA23074, and R01CA24226. K.D.M is additionally supported by the ARCS Foundation Phoenix Chapter. Citation Format: Kendra D. Marr, Hina Arif-Tiwari, Jaime M. Gard, Noel E. Warfel, Raymond B. Nagle, Anne E. Cress. Cancer cell invasion through a complex and dynamic smooth muscle microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB233.
• Martinez, F., Brucks, E., Otsuji, J., Mehnoor, H., Arif-Tiwari, H., Babiker, H. M., & Recio-Boiles, A. (2021). Using Advanced Molecular Profiling to Identify the Origin of and Tailor Treatment for an Intracranial Mass of Unknown Primary. JCO precision oncology, 5, 981-987.
• Sadovnikov, I., Anthony, M., Mushtaq, R., Khreiss, M., Gavini, H., & Arif-Tiwari, H. (2021). Role of magnetic resonance imaging in Bouveret's syndrome: A case report with review of the literature. Clinical imaging, 77, 43-47.
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  Bouveret's syndrome is a rare form of gallstone ileus occurring due to obstructing gallstone into the proximal duodenum through a cholecystoduodenal fistula. We report the case of a 72-year-old female presenting with abdominal pain secondary to a large gallstone in the region of the duodenal bulb, causing the upstream gastric obstruction. Here we discuss the clinical features, imaging technologies, and surgical management of Bouveret's syndrome.
• Sawyer, D. M., Mushtaq, R., Vedantham, S., Shareef, F., Desoky, S. M., Arif Tiwari, H., Gilbertson-Dahdal, D., & Udayasankar, U. (2021). Performance of overnight on-call radiology residents in interpreting unenhanced abdominopelvic MRI studies performed for pediatric right lower quadrant abdominal pain. Pediatric Radiology.
• Sawyer, D. M., Mushtaq, R., Vedantham, S., Shareef, F., Desoky, S. M., Arif-Tiwari, H., Gilbertson-Dahdal, D. L., & Udayasankar, U. K. (2021). Performance of overnight on-call radiology residents in interpreting unenhanced abdominopelvic magnetic resonance imaging studies performed for pediatric right lower quadrant abdominal pain. Pediatric radiology, 51(8), 1378-1385.
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  Abdominopelvic magnetic resonance imaging (MRI) is increasingly being used to evaluate children with abdominal pain suspected of having acute appendicitis. At our institution, these examinations are preliminarily interpreted by radiology residents, especially when performed after hours.
• Scholz, F. J., Sayed, R. F., Ram, R., Palmer, S. L., Lockhart, M. E., Lewis, S., Lalwani, N., Khatri, G., Kamath, A., Jambhekar, K., Flusberg, M., Fielding, J. R., Chernyak, V., & Arif-tiwari, H. (2021). MR defecography technique: recommendations of the society of abdominal radiology's disease-focused panel on pelvic floor imaging.. Abdominal Radiology, 46(4), 1351-1361. doi:10.1007/s00261-019-02160-7
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  To develop recommendations for magnetic resonance (MR) defecography technique based on consensus of expert radiologists on the disease-focused panel of the Society of Abdominal Radiology (SAR). An extensive questionnaire was sent to a group of 20 experts from the disease-focused panel of the SAR. The questionnaire encompassed details of technique and MRI protocol used for evaluating pelvic floor disorders. 75% agreement on questionnaire responses was defined as consensus. The expert panel reached consensus for 70% of the items and provided the basis of these recommendations for MR defecography technique. There was unanimous agreement that patients should receive coaching and explanation of commands used during MR defecography, the rectum should be distended with contrast agent, and that sagittal T2-weighted images should include the entire pelvis within the field of view. The panel also agreed unanimously that IV contrast should not be used for MR defecography. Additional areas of consensus ranged in agreement from 75 to 92%. We provide a set of consensus recommendations for MR defecography technique based on a survey of expert radiologists in the SAR pelvic floor dysfunction disease-focused panel. These recommendations can be used to develop a standardized imaging protocol.
• Steiner, A., Sheridan, A. D., Ram, R., Palmer, S. L., Khatri, G., Jambhekar, K., Glanc, P., & Arif-tiwari, H. (2021). Meshy business: MRI and ultrasound evaluation of pelvic floor mesh and slings. Abdominal Radiology, 46(4), 1414-1442. doi:10.1007/s00261-020-02404-x
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  Pelvic floor disorders are a complex set of conditions including but not limited to stress urinary incontinence and pelvic organ prolapse that generally affect older and multiparous women. Of the several surgical options available for treatment of these conditions, synthetic mid-urethral slings for stress urinary incontinence and vaginal mesh for pelvic organ prolapse are amenable to imaging evaluation by ultrasound and magnetic resonance imaging techniques. Ultrasound can evaluate the sub- and immediate peri-urethral portions of sling due to its ability to differentiate synthetic material from native tissues with real-time imaging, while MRI is able to better depict the global pelvic floor anatomy and assess the more distant components of mesh and slings material. Given the high prevalence of pelvic floor disorders and complications after surgical repair, it is important that radiologists familiarize themselves with normal and abnormal imaging findings after these procedures. This article provides a review of the spectrum of imaging findings in patients after pelvic floor repair with synthetic mid-urethral slings and vaginal mesh.
• Thompson, E., Banerjee, S., Thompson, S., Silva, R., Muse, A., Arif-Tiwari, H., Scott, A. J., & Nfonsam, V. (2021). Incidence and predictors of brain metastasis in colorectal cancer patients. International journal of colorectal disease.
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  Brain metastasis (BM) in colorectal cancer patients is rare and is associated with dismal outcomes. Our study aims to evaluate the incidence and predictors of BM in patients with colorectal cancer.
• Tiwari, H. A., Shah, H., Ram, R., Nadeem, M., Jambhekar, K., Tiwari, H. A., Shah, H., Ram, R., Nadeem, M., & Jambhekar, K. (2021). Revisiting the Spleen—An Imaging Review of the Common and Uncommon Splenic Pathology. Journal of Gastrointestinal and Abdominal Radiology, 04(02), 127-138. doi:10.1055/s-0040-1721626
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  The spleen is the largest lymphatic organ and is responsible for both hematological and immunological functions. Several common etiologies such as trauma, developmental variants, infectious/inflammatory conditions, and benign and malignant lesions can occur in the spleen. The role of imaging modalities such as ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) in diagnosing these conditions continues to evolve. The main objective of this review article is to illustrate the role of imaging in identifying the common and uncommon pathology of the spleen.
• , E. P., Bashir, M. R., Horowitz, J. M., Kamel, I. R., Arif-Tiwari, H., Asrani, S. K., Chernyak, V., Goldstein, A., Grajo, J. R., Hindman, N. M., Kamaya, A., McNamara, M. M., Porter, K. K., Solnes, L. B., Srivastava, P. K., Zaheer, A., & Carucci, L. R. (2020). ACR Appropriateness Criteria® Chronic Liver Disease. Journal of the American College of Radiology : JACR, 17(5S), S70-S80.
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  The liver fibrosis stage is the most important clinical determinate of morbidity and mortality in patients with chronic liver diseases. With newer therapies, liver fibrosis can be stabilized and possibly reversed, thus accurate diagnosis and staging of liver fibrosis are clinically important. Ultrasound, CT, and conventional MRI can be used to establish the diagnosis of advanced fibrosis/cirrhosis but have limited utility for assessing earlier stages of fibrosis. Elastography-based ultrasound and MRI techniques are more useful for assessment of precirrhotic hepatic fibrosis. In patients with advanced fibrosis at risk for hepatocellular carcinoma (HCC), ultrasound is the surveillance modality recommended by international guidelines in nearly all circumstances. However, in patients in whom ultrasound does not assess the liver well, including those with severe steatosis or obesity, multiphase CT or MRI may have a role in surveillance for HCC. Both multiphase CT and MRI can be used for continued surveillance in patients with a history of HCC, and contrast-enhanced ultrasound may have an emerging role in this setting. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
• , E. P., Chernyak, V., Horowitz, J. M., Kamel, I. R., Arif-Tiwari, H., Bashir, M. R., Cash, B. D., Farrell, J., Goldstein, A., Grajo, J. R., Gupta, S., Hindman, N. M., Kamaya, A., McNamara, M. M., Porter, K. K., Solnes, L. B., Srivastava, P. K., Zaheer, A., & Carucci, L. R. (2020). ACR Appropriateness Criteria® Liver Lesion-Initial Characterization. Journal of the American College of Radiology : JACR, 17(11S), S429-S446.
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  Incidental liver masses are commonly identified on imaging performed for other indications. Since the prevalence of benign focal liver lesions in adults is high, even in patients with primary malignancy, accurate characterization of incidentally detected lesions is of paramount clinical importance. This document reviews utilization of various imaging modalities for characterization of incidentally detected liver lesions, discussed in the context of several clinical scenarios. For each clinical scenario, a summary of current evidence supporting the use of a given diagnostic modality is reported. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
• , E. P., Fábrega-Foster, K., Kamel, I. R., Horowitz, J. M., Arif-Tiwari, H., Bashir, M. R., Chernyak, V., Goldstein, A., Grajo, J. R., Hindman, N. M., Kamaya, A., McNamara, M. M., Porter, K. K., Scheiman, J. M., Solnes, L. B., Srivastava, P. K., Zaheer, A., & Carucci, L. R. (2020). ACR Appropriateness Criteria® Pancreatic Cyst. Journal of the American College of Radiology : JACR, 17(5S), S198-S206.
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  Incidental pancreatic cysts are increasingly detected on imaging studies performed for unrelated indications and may be incompletely characterized on these studies. Adequate morphological characterization is critical due to the small risk of malignant degeneration associated with neoplastic pancreatic cysts, as well as the risk of associated pancreatic adenocarcinoma. For all pancreatic cysts, both size and morphology determine management. Specifically, imaging detection of features, such as pancreatic ductal communication and presence or absence of worrisome features or high-risk stigmata, have important management implications. The recommendations in this publication determine the appropriate initial imaging study to further evaluate a pancreatic cyst that was incidentally detected on a nondedicated imaging study. The recommendations are designed to maximize the yield of diagnostic information in order to better risk-stratify pancreatic cysts and assist in guiding future management. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
• Dohogne, B. J., Srinivasan, S., Arif-Tiwari, H., & Potharaju, A. (2020). Nontyphoidal Salmonella as a Cause of Mediastinal Abscess in a Patient With Extensive Cardiac Surgery. Cureus, 12(8), e9924.
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  Focal infections caused by nontyphoidal Salmonella (NTS) are relatively rare and usually self-limited. Those with cardiac surgical history are predisposed to intrathoracic seeding, including mediastinal infections and abscesses. We report a case of a 39-year-old Hispanic male with a complex past medical history of Tetralogy of Fallot with an initial presentation of Salmonella gastroenteritis and concern for sepsis. The patient did not clinically improve on ceftriaxone despite appropriate cultures and susceptibilities, and another source of infection was speculated. A chest CT scan showed development of a mediastinal abscess with compression of the right ventricular outflow tract. The patient was not deemed an appropriate surgical candidate and was managed conservatively on ceftriaxone and ciprofloxacin. He was discharged in stable condition. This case of NTS infection associated with a mediastinal abscess is a rare occurrence, and management is complicated. To improve morbidity and mortality, early imaging is essential to diagnose distal seeding of the infection in patients with enteral infections who do not show clinical improvement despite appropriate antibiotic treatment. Surgery is the standard of care, but conservative management might be required in certain high-risk cases.
• Ewongwo, A., Hamidi, M., Alattar, Z., Ayotunde, O. P., Tiwari, H. A., Elquza, E., Scott, A., Hanna, K., & Nfonsam, V. (2020). Contributing factors and short-term surgical outcomes of patients with early-onset rectal cancer. American journal of surgery, 219(4), 578-582.
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  The aim of this study was to evaluate patient factors that contribute to increased incidence of early onset rectal cancer and analyze the short-term surgical outcomes of patients undergoing surgery.
• Gopireddy, D. R., Soule, E., Arif-Tiwari, H., Sharma, S., Kanmaniraja, D., Jain, K., Letter, H., & Lall, C. (2020). Spectrum of CT Findings Related to Bowel Adhesions Without Bowel Obstruction: A Comprehensive Imaging Review. Journal of clinical imaging science, 10, 80.
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  Post-operative adhesions can occur following abdominal or pelvic surgery and are a significant cause of morbidity and mortality. Adhesions are an important cause of abdominal complaints, especially chronic abdominal pain, infertility, and bowel obstruction; responsible for an estimated $2.3 billion annual burden in the United States alone. There is a paucity of literature describing CT findings indicative of the presence of adhesions, however, findings suggestive of this entity may be discovered by a discerning eye. Early recognition and diagnosis may be beneficial for reducing consumption of health-care resources related to abdominal complaints. In addition, these findings may impact surgical planning and facilitate recognition of adhesion-related complications, said to be responsible for a significant number of malpractice claims. The following review discusses various CT findings which may indicate the presence of adhesions. These findings may initially be overlooked, but remain valuable as the clinical presentation evolves to become consistent with adhesive disease. Detection of bowel and peritoneal adhesions can be recognized on imaging modalities based on distortion of bowel loops. This pictorial review illustrates the spectrum of findings related to bowel adhesions encountered on computed tomography imaging.
• Kulkarni, N. M., Mannelli, L., Zins, M., Bhosale, P. R., Arif-Tiwari, H., Brook, O. R., Hecht, E. M., Kastrinos, F., Wang, Z. J., Soloff, E. V., Tolat, P. P., Sangster, G., Fleming, J., Tamm, E. P., & Kambadakone, A. R. (2020). White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology's disease-focused panel for pancreatic ductal adenocarcinoma: Part II, update on imaging techniques and screening of pancreatic cancer in high-risk individuals. Abdominal radiology (New York).
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  Pancreatic ductal adenocarcinoma (PDAC) is an aggressive gastrointestinal malignancy with a poor 5-year survival rate. Its high mortality rate is attributed to its aggressive biology and frequently late presentation. While surgical resection remains the only potentially curative treatment, only 10-20% of patients will present with surgically resectable disease. Over the past several years, development of vascular bypass graft techniques and introduction of neoadjuvant treatment regimens have increased the number of patients who can undergo resection with a curative intent. While the role of conventional imaging in the detection, characterization, and staging of patients with PDAC is well established, its role in monitoring treatment response, particularly following neoadjuvant therapy remains challenging because of the complex anatomic and histological nature of PDAC. Novel morphologic and functional imaging techniques (such as DECT, DW-MRI, and PET/MRI) are being investigated to improve the diagnostic accuracy and the ability to measure response to therapy. There is also a growing interest to detect PDAC and its precursor lesions at an early stage in asymptomatic patients to increase the likelihood of achieving cure. This has led to the development of pancreatic cancer screening programs. This article will review recent updates in imaging techniques and the current status of screening and surveillance of individuals at a high risk of developing PDAC.
• Kulkarni, N. M., Soloff, E. V., Tolat, P. P., Sangster, G. P., Fleming, J. B., Brook, O. R., Wang, Z. J., Hecht, E. M., Zins, M., Bhosale, P. R., Arif-Tiwari, H., Mannelli, L., Kambadakone, A. R., & Tamm, E. P. (2020). White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology's disease-focused panel for pancreatic ductal adenocarcinoma: Part I, AJCC staging system, NCCN guidelines, and borderline resectable disease. Abdominal radiology (New York).
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  Pancreatic ductal adenocarcinoma (PDAC) is an aggressive gastrointestinal malignancy with a poor 5-year survival rate. Accurate staging of PDAC is an important initial step in the development of a stage-specific treatment plan. Different staging systems/consensus statements convened by different societies and academic practices are currently used. The most recent version of the American Joint Committee on Cancer (AJCC) tumor/node/metastases (TNM) staging system for PDAC has shifted its focus from guiding management to assessing prognosis. In order to preoperatively define the resectability of PDAC and to guide management, additional classification systems have been developed. The National Comprehensive Cancer Network (NCCN) guidelines, one of the most commonly used systems, provide recommendations on the management and the determination of resectability for PDAC. The NCCN divides PDAC into three categories of resectability based on tumor-vessel relationship: 'resectable,' 'borderline resectable,' and 'unresectable'. Among these, the borderline disease category is of special interest given its evolution over time and the resulting variations in the definition and the associated recommendations for management between different societies. It is important to be familiar with the evolving criteria, and treatment and follow-up recommendations for PDAC. In this article, the most current AJCC staging (8th edition), NCCN guidelines (version 2.2019-April 9, 2019), and challenges and controversies in borderline resectable PDAC are reviewed.
• Mushtaq, R., Jayagurunathan, U., Arif Tiwari, H., & Yaddanapudi, K. (2020). Pulmonary MRI: Applications and Use Cases. Current Pulmonology Reports. doi:https://doi.org/10.1007/s13665-020-00257-9
• Pollock, G. R., Arif Tiwari, H., Chartier, S., Vedantham, S., Funk, J., & Twiss, C. O. (2020). Comparison of magnetic resonance defecography grading with POP-Q staging and Baden-Walker grading in the evaluation of female pelvic organ prolapse. Neurourology and Urodynamics.
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  The physical examination and pelvic imaging with MRI are often used in the pre-operative evaluation of pelvic organ prolapse. The objective of this study was to compare grading of prolapse on defecography phase of dynamic magnetic resonance imaging (dMRI) with physical examination (PE) grading using both the Pelvic Organ Prolapse Quantification (POP-Q) staging and Baden-Walker (BW) grading systems in the evaluation of pelvic organ prolapse (POP).
• Ram, R., Jambhekar, K., Glanc, P., Steiner, A., Sheridan, A. D., Arif-Tiwari, H., Palmer, S. L., & Khatri, G. (2020). Meshy business: MRI and ultrasound evaluation of pelvic floor mesh and slings. Abdominal radiology (New York).
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  Pelvic floor disorders are a complex set of conditions including but not limited to stress urinary incontinence and pelvic organ prolapse that generally affect older and multiparous women. Of the several surgical options available for treatment of these conditions, synthetic mid-urethral slings for stress urinary incontinence and vaginal mesh for pelvic organ prolapse are amenable to imaging evaluation by ultrasound and magnetic resonance imaging techniques. Ultrasound can evaluate the sub- and immediate peri-urethral portions of sling due to its ability to differentiate synthetic material from native tissues with real-time imaging, while MRI is able to better depict the global pelvic floor anatomy and assess the more distant components of mesh and slings material. Given the high prevalence of pelvic floor disorders and complications after surgical repair, it is important that radiologists familiarize themselves with normal and abnormal imaging findings after these procedures. This article provides a review of the spectrum of imaging findings in patients after pelvic floor repair with synthetic mid-urethral slings and vaginal mesh.
• Sarmad, M., Ishfaq, A., Arif, H., & Zaka, S. M. (2020). Effect of short-term cold temperature stress on development, survival and reproduction of Dysdercus koenigii (Hemiptera: Pyrrhocoridae). Cryobiology, 92, 47-52.
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  Red cotton bug Dysdercus koenigii F. (Hemiptera: Pyrrhocoridae), is found destructive pest in various cotton growing areas. Under natural conditions insects are highly subjected to thermal stresses. In present work the developmental duration and survival rate of all immature stages, adult longevity and reproduction of D. koenigii by exposed to rapid changes in very low temperatures were studied. When 3 h short-stress of low temperatures (12-0 °C) was given to different stages of D. koenigii, the results revealed that survival rate of all stages were significantly reduced. Survival rate of female was significantly higher than male after exposed to cold temperature stress. Mating percentage, fecundity and hatching percentage were decreased significantly with the decrease of short-term cold temperature stress. Based on these results, we concluded that the developmental duration, survival rate and reproduction of D. koenigii significantly affected when they exposed to short term cold temperature stress.
• Udayasankar, U., Udayasankar, U., Udayasankar, U., Gilbertson-Dahdal, D., Gilbertson-Dahdal, D., Gilbertson-Dahdal, D., Morello, F., Morello, F., Morello, F., Arif Tiwari, H., Arif Tiwari, H., Arif Tiwari, H., Desoky, S., Desoky, S., Desoky, S., Warner, J., Warner, J., & Warner, J. (2020). Unenhanced MRI of the Abdomen and Pelvis in the Comprehensive Evaluation of Acute Atraumatic Abdominal Pain in Children. American Journal of Roentgenology.
• Wang, Z. J., Arif-Tiwari, H., Zaheer, A., Ameli, S., Bhosale, P. R., Do, R. K., Goenka, A. H., Guimares, A. R., Sangster, G. P., Soloff, E. V., Tamm, E. P., Zins, M., & Kambadakone, A. R. (2020). Therapeutic response assessment in pancreatic ductal adenocarcinoma: society of abdominal radiology review paper on the role of morphological and functional imaging techniques. Abdominal radiology (New York), 45(12), 4273-4289.
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  Pancreatic ductal adenocarcinoma (PDA) is the third leading cause of cancer-related death in the United States and is projected to be the second by 2030. Systemic combination chemotherapy is considered an essential first-line treatment for the majority of patients with PDA, in both the neoadjuvant and palliative settings. In addition, a number of novel therapies are being tested in clinical trials for patients with advanced PDA. In all cases, accurate and timely assessment of treatment response is critical to guide therapy, reduce drug toxicities and cost from a failing therapy, and aid adaptive clinical trials. Conventional morphological imaging has significant limitations, especially in the context of determining primary tumor response and resectability following neoadjuvant therapies. In this article, we provide an overview of current therapy options for PDA, highlight several morphological imaging findings that may be helpful to reduce over-staging following neoadjuvant therapy, and discuss a number of emerging imaging, and non-imaging, tools that have shown promise in providing a more precise quantification of disease burden and treatment response in PDA.
• Warner, J., Desoky, S., Arif Tiwari, H., Morello, F., Gilbertson-Dahdal, D., & Udayasankar, U. (2020). Non-enhanced MRI of the Abdomen and Pelvis in Comprehensive Evaluation of Acute Atraumatic Abdominal Pain in Children. American Journal of Radiology.
• Warner, J., Desoky, S., Tiwari, H. A., Morello, F., Gilbertson, D., & Udayasankar, U. (2020). Unenhanced MRI of the Abdomen and Pelvis in the Comprehensive Evaluation of Acute Atraumatic Abdominal Pain in Children. AJR. American journal of roentgenology, 215(5), 1218-1228.
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  The purpose of this study is to show the utility of rapid unenhanced MRI in the comprehensive assessment of acute atraumatic abdominal pain in children, including appendicitis and alternate diagnoses, and to review the MRI features of common acute abdominal and pelvic conditions in a large, single-institution cohort. Rapid unenhanced MRI is an excellent option for the initial, comprehensive evaluation of acute abdominal emergencies in pediatric patients because it can diagnose the full range of presenting abnormalities, including causes of abdominal pain warranting surgical and nonsurgical management.
• , E. P., Hindman, N. M., Arif-Tiwari, H., Kamel, I. R., Al-Refaie, W. B., Bartel, T. B., Cash, B. D., Chernyak, V., Goldstein, A., Grajo, J. R., Horowitz, J. M., Kamaya, A., McNamara, M. M., Porter, K. K., Srivastava, P. K., Zaheer, A., & Carucci, L. R. (2019). ACR Appropriateness Criteria Jaundice. Journal of the American College of Radiology : JACR, 16(5S), S126-S140.
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  Jaundice is the end result of myriad causes, which makes the role of imaging in this setting particularly challenging. In the United States, the most common causes of all types of jaundice fall into four categories including hepatitis, alcoholic liver disease, blockage of the common bile duct by a gallstone or tumor, and toxic reaction to a drug or medicinal herb. Clinically, differentiating between the various potential etiologies of jaundice requires a detailed history, targeted physical examination, and pertinent laboratory studies, the results of which allow the physician to categorize the type of jaundice into mechanical or nonmechanical causes. Imaging modalities used to evaluate the jaundiced patient (all etiologies) include abdominal ultrasound (US), CT, MR cholangiopancreatography, endoscopic retrograde cholangiopancreatography and endoscopic US. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
• , E. P., Peterson, C. M., McNamara, M. M., Kamel, I. R., Al-Refaie, W. B., Arif-Tiwari, H., Cash, B. D., Chernyak, V., Goldstein, A., Grajo, J. R., Hindman, N. M., Horowitz, J. M., Noto, R. B., Porter, K. K., Srivastava, P. K., Zaheer, A., & Carucci, L. R. (2019). ACR Appropriateness Criteria Right Upper Quadrant Pain. Journal of the American College of Radiology : JACR, 16(5S), S235-S243.
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  Although right upper quadrant pain is a very common clinical presentation, it can be nonspecific. However, acute cholecystitis is very often the diagnosis of exclusion. This review focuses on the recommended imaging evaluation in the most commonly encountered clinical scenarios presenting with right upper quadrant abdominal pain, including suspected biliary disease, suspected acute cholecystitis, and suspected acalculous cholecystitis. This document hopes to clarify the appropriate utilization of the many imaging procedures that are available and commonly employed in these clinical settings. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
• , E. P., Porter, K. K., Zaheer, A., Kamel, I. R., Horowitz, J. M., Arif-Tiwari, H., Bartel, T. B., Bashir, M. R., Camacho, M. A., Cash, B. D., Chernyak, V., Goldstein, A., Grajo, J. R., Gupta, S., Hindman, N. M., Kamaya, A., McNamara, M. M., & Carucci, L. R. (2019). ACR Appropriateness Criteria® Acute Pancreatitis. Journal of the American College of Radiology : JACR, 16(11S), S316-S330.
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  Acute pancreatitis (AP) is divided into two types: interstitial edematous and necrotizing. AP severity is classified clinically into mild, moderately severe, and severe, depending on the presence and persistence of organ failure and local or systemic complications. The revised Atlanta classification divides the clinical course of AP into an early (first week) and late phase (after first week) and the clinical phase determines the role of imaging. Imaging has a limited role in the early phase. In the early phase with typical presentations of AP, ultrasound is usually the only appropriate modality and is used for the detection of gallstones. CT and MRI are appropriate in the early phase in equivocal presentations. In the late phase (or at least 48-72 hours after presentation), CT and MRI play a primary role in the imaging of patients with AP for evaluation of etiology, complications, extent of disease, intervention, and follow-up; CT is particularly useful in patients with suspected acute hemorrhage. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
• Arif Tiwari, H., Taylor, P., Kalb, B., & Martin, D. (2019). Magnetic Resonance Enterography in Inflammatory Bowel Disease. Applied Radiology, 48(1), 9-15.
• Arif-Tiwari, H., Kalb, B. T., Bisla, J. K., & Martin, D. R. (2019). Classification and Diagnosis of Cystic Renal Tumors: Role of MR Imaging Versus Contrast-Enhanced Ultrasound. Magnetic resonance imaging clinics of North America, 27(1), 33-44.
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  Superior soft tissue and contrast resolution of MR imaging benefits sensitivity to kidney cyst features and classification, which may have an impact on patient management and outcomes. Contrast-enhanced ultrasound (CEUS) may have nearly similar sensitivity for detection of cyst features yet is dependent on patient body habitus and adequacy of visualization windows for the kidneys, which does not have the same impact on MR imaging results. Both MR imaging and CEUS may provide superior kidney cyst assessment compared with contrast-enhanced CT; however, further research is needed, particularly for the identification of role of CEUS.
• Bahrami, S., Khatri, G., Sheridan, A. D., Palmer, S. L., Lockhart, M. E., Arif-Tiwari, H., & Glanc, P. (2019). Pelvic floor ultrasound: when, why, and how?. Abdominal radiology (New York).
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  Pelvic floor disorders are a significant medical issue, reportedly affecting nearly one in four women in the United States. Nonetheless, until the last decade, there has been relatively limited imaging research into this highly prevalent disorder. The three major imaging modalities utilized to assess pelvic floor function are ultrasound, MRI and fluoroscopy. Pelvic floor ultrasound is a rapidly emerging technique which takes advantage of the widespread availability of ultrasound, the non-invasive and relatively inexpensive approach and the incorporation of real-time imaging and software advances which permit 3-D volume imaging. Pelvic floor ultrasound provides the opportunity to optimize patient counseling and enhance pre-operative planning by providing an anatomic and functional roadmap for the referring clinician. We recommend the consideration of pelvic floor ultrasound, as described here, as an addition to the imaging armamentarium available to physicians and surgeons serving this patient population.
• Bisla, J. K., Saranathan, M., Martin, D. R., Arif-Tiwari, H., & Kalb, B. T. (2019). MR Imaging Evaluation of the Kidneys in Patients with Reduced Kidney Function: Noncontrast Techniques Versus Contrast-Enhanced Techniques. Magnetic resonance imaging clinics of North America, 27(1), 45-57.
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  MR imaging has been optimized for the evaluation of a multitude of disease processes affecting the kidneys. A wide variety of noncontrast methods are available for the evaluation of both kidney structure and function, which are especially useful in clinical scenarios that obviate the use of intravenous contrast. Contrast-enhanced methods remain important, especially for tumor evaluation, and are used increasingly for functional analysis of quantitative biometrics, such as glomerular filtration rate and kidney blood flow.
• Kanmaniraja, D., Arif-Tiwari, H., Palmer, S. L., Kamath, A., Lewis, S. C., Flusberg, M., Kobi, M., Lockhart, M. E., & Chernyak, V. (2019). MR defecography review. Abdominal radiology (New York).
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  Pelvic floor dysfunction is a relatively common but often complex condition, presenting with a variety of clinical symptoms, especially when it involves multiple compartments. Clinical exam alone is often inadequate and requires a complementary imaging study. Magnetic resonance defecography (MRD) is an excellent noninvasive diagnostic study with its multiplanar capability, lack of ionizing radiation and excellent soft tissue resolution. It can identify both anatomic and functional abnormalities in the pelvic floor and specifically excels in its ability to simultaneously detect multicompartmental pathology and help with vital pre-operative assessment. This manuscript reviews the relevant anatomical landmarks, describes the optimal technique, highlights an approach to the interpretation of MRD, and provides an overview of the various pelvic floor disorders in the different anatomical compartments.
• Lalwani, N., El Sayed, R. F., Kamath, A., Lewis, S., Arif, H., & Chernyak, V. (2019). Imaging and clinical assessment of functional defecatory disorders with emphasis on defecography. Abdominal radiology (New York).
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  Functional defecation disorders (FDD) encompass causes of constipation associated with anorectal dysfunction, which include dyssynergia or inadequate defecatory propulsion. FDD are frequently encountered in clinical practice and may affect up to 33-50% of patients with chronic constipation. The etiology of FDD is unclear, however, it has been defined as an acquired, but subliminal behavioral disorder. Pathophysiologic mechanisms may include discoordination of rectoanal muscles, paradoxical contraction or insufficient relaxation of puborectalis and/or anal sphincter during defecation, and sluggish colonic transit. A combination of comprehensive clinical assessment, digital rectal examination and a battery of physiologic tests are needed to make an accurate diagnosis of FDD. Defecography may play a crucial role in the evaluation of FDD, especially when a balloon expulsion test (BET) and/or anorectal manometry (ARM) are equivocal or demonstrate contradictory results. In this review, we provide a thorough overview of the epidemiology, pathophysiology, diagnostic criteria, clinical and imaging evaluation, and treatment options for FDD, with an emphasis on available diagnostic imaging tools such as defecography and conventional fluoroscopic methods.
• Lalwani, N., Khatri, G., El Sayed, R. F., Ram, R., Jambhekar, K., Chernyak, V., Kamath, A., Lewis, S., Flusberg, M., Scholz, F., Arif-Tiwari, H., Palmer, S. L., Lockhart, M. E., & Fielding, J. R. (2019). MR defecography technique: recommendations of the society of abdominal radiology's disease-focused panel on pelvic floor imaging. Abdominal radiology (New York).
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  To develop recommendations for magnetic resonance (MR) defecography technique based on consensus of expert radiologists on the disease-focused panel of the Society of Abdominal Radiology (SAR).
• Liau, J., Goldberg, D., & Arif Tiwari, H. (2019). Prostate Cancer Detection and Diagnosis: Role of Ultrasound with MRI Correlates. Current Radiology Reports.
• Pollock, G. R., Twiss, C. O., Chartier, S., Vedantham, S., Funk, J., & Arif Tiwari, H. (2019). Comparison of magnetic resonance defecography grading with POP-Q staging and Baden-Walker grading in the evaluation of female pelvic organ prolapse. Abdominal radiology (New York).
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  The physical examination and pelvic imaging with MRI are often used in the pre-operative evaluation of pelvic organ prolapse. The objective of this study was to compare grading of prolapse on defecography phase of dynamic magnetic resonance imaging (dMRI) with physical examination (PE) grading using both the Pelvic Organ Prolapse Quantification (POP-Q) staging and Baden-Walker (BW) grading systems in the evaluation of pelvic organ prolapse (POP).
• Rubenstein, C. S., Gard, J. M., Wang, M., McGrath, J. E., Ingabire, N., Hinton, J. P., Marr, K. D., Simpson, S. J., Nagle, R. B., Miranti, C. K., Warfel, N. A., Garcia, J. G., Arif-Tiwari, H., & Cress, A. E. (2019). Gene Editing of α6 Integrin Inhibits Muscle Invasive Networks and Increases Cell-Cell Biophysical Properties in Prostate Cancer. Cancer research, 79(18), 4703-4714.
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  Human prostate cancer confined to the gland is indolent (low-risk), but tumors outside the capsule are aggressive (high-risk). Extracapsular extension requires invasion within and through a smooth muscle-structured environment. Because integrins respond to biomechanical cues, we used a gene editing approach to determine if a specific region of laminin-binding α6β1 integrin was required for smooth muscle invasion both and . Human tissue specimens showed prostate cancer invasion through smooth muscle and tumor coexpression of α6 integrin and E-cadherin in a cell-cell location and α6 integrin in a cell-extracellular matrix (ECM) distribution. Prostate cancer cells expressing α6 integrin (DU145 α6WT) produced a 3D invasive network on laminin-containing Matrigel and invaded into smooth muscle both and . In contrast, cells without α6 integrin (DU145 α6KO) and cells expressing an integrin mutant (DU145 α6AA) did not produce invasive networks, could not invade muscle both and , and surprisingly formed 3D cohesive clusters. Using electric cell-substrate impedance testing, cohesive clusters had up to a 30-fold increase in normalized resistance at 400 Hz (cell-cell impedance) as compared with the DU145 α6WT cells. In contrast, measurements at 40,000 Hz (cell-ECM coverage) showed that DU145 α6AA cells were two-fold decreased in normalized resistance and were defective in restoring resistance after a 1 μmol/L S1P challenge as compared with the DU145 α6WT cells. The results suggest that gene editing of a specific α6 integrin extracellular region, not required for normal tissue function, can generate a new biophysical cancer phenotype unable to invade the muscle, presenting a new therapeutic strategy for metastasis prevention in prostate cancer. SIGNIFICANCE: This study shows an innovative strategy to block prostate cancer metastasis and invasion in the muscle through gene editing of a specific α6 integrin extracellular region.
• Steiner, A., Marks, R., Bahrami, S., & Arif-Tiwari, H. (2019). How to develop and sustain a successful pelvic floor MRI practice. Abdominal radiology (New York).
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  Magnetic resonance imaging (MRI) of the pelvic floor has become a commonly requested diagnostic tool for pelvic floor assessment. We provide a practical guide for developing, growing, and troubleshooting a dedicated pelvic floor imaging service.
• Kalb, B. T., Martin, D. R., Vedantham, S., Funk, J., Lin, F. C., Twiss, C. O., Arif Tiwari, H., Arif Tiwari, H., Twiss, C. O., Lin, F. C., Funk, J., Vedantham, S., Martin, D. R., & Kalb, B. T. (2018). Improved Detection of Pelvic Organ Prolapse: Comparative Utility of Defecography Phase Sequence to Nondefecography Valsalva Maneuvers in Dynamic Pelvic Floor Magnetic Resonance Imaging. Current Problems in Diagnostic Radiology.
• Lin, F., Funk, J., Arif Tiwari, H., Kalb, B. T., & Twiss, C. O. (2017). Dynamic Pelvic MRI Evaluation of Pelvic Organ Prolapse Compared to Physical Exam Findings. Journal of Urology.
• Twiss, C. O., Kalb, B. T., Arif Tiwari, H., Funk, J. T., & Lin, F. C. (2018). Dynamic Pelvic MRI Evaluation of Pelvic Organ Prolapse Compared to Physical Exam Findings. Urology, 119, 49-54. doi:https://doi.org/10.1016/j.urology.2018.05.031
• Witte, R. S., Karunakaran, C., Zuniga, A. N., Schmitz, H., & Arif, H. (2018). Frontiers of cancer imaging and guided therapy using ultrasound, light, and microwaves. Clinical & experimental metastasis, 35(5-6), 413-418.
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  This review describes emerging techniques within the last 5 years that employ ultrasound for detecting and staging malignancy, tracking metastasis, and guiding treatment. Ultrasound elastography quantifies soft tissue elastic properties that change as a tumor grows and proliferates. Hybrid imaging modalities that combine ultrasound with light or microwave energy provide novel contrast for mapping blood oxygen saturation, transport of particles through lymphatic vessels and nodes, and real-time feedback for guiding needle biopsies. Combining these methods with smart nanoparticles and contrast agents further promotes new paradigms for cancer imaging and therapy.
• , E. P., Horowitz, J. M., Kamel, I. R., Arif-Tiwari, H., Asrani, S. K., Hindman, N. M., Kaur, H., McNamara, M. M., Noto, R. B., Qayyum, A., & Lalani, T. (2017). ACR Appropriateness Criteria Chronic Liver Disease. Journal of the American College of Radiology : JACR, 14(11S), S391-S405.
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  Because liver fibrosis can be treated, it is important to diagnose liver fibrosis noninvasively and monitor response to treatment. Although ultrasound (grayscale and Doppler) can diagnose cirrhosis, it does so unreliably using morphologic and sonographic features and cannot diagnose the earlier, treatable stages of hepatic fibrosis. Transient elastography, ultrasound elastography with acoustic radiation force impulse, and MR elastography are modalities that can assess for hepatic fibrosis. Although all international organizations recommend ultrasound for screening for hepatocellular carcinoma, ultrasound is particularly limited for identifying hepatocellular carcinoma in patients with obesity, nonalcoholic fatty liver disease, and nodular cirrhotic livers. In these patient groups as well as patients who are on the liver transplant wait list, ultrasound is so limited that consideration can be made for screening for hepatocellular carcinoma with either MRI or multiphase CT. Additionally, patients who have been previously diagnosed with and treated for hepatocellular carcinoma require continued surveillance for recurrent hepatocellular carcinoma. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
• , E. P., Horowitz, J. M., Kamel, I. R., Arif-Tiwari, H., Asrani, S. K., Hindman, N. M., Kaur, H., McNamara, M. M., Noto, R. B., Qayyum, A., & Lalani, T. (2017). ACR Appropriateness Criteria Chronic Liver Disease. Journal of the American College of Radiology : JACR, 14(5S), S103-S117.
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  Because liver fibrosis can be treated, it is important to diagnose liver fibrosis noninvasively and monitor response to treatment. Although ultrasound (grayscale and Doppler) can diagnose cirrhosis, it does so unreliably using morphologic and sonographic features and cannot diagnose the earlier, treatable stages of hepatic fibrosis. Transient elastography, ultrasound elastography with acoustic radiation force impulse, and MR elastography are modalities that can assess for hepatic fibrosis. Although all international organizations recommend ultrasound for screening for hepatocellular carcinoma, ultrasound is particularly limited for identifying hepatocellular carcinoma in patients with obesity, nonalcoholic fatty liver disease, and nodular cirrhotic livers. In these patients, as well as patients who are on the liver transplant wait list, ultrasound is so limited that consideration can be made for screening for hepatocellular carcinoma with either MRI or multiphase CT. Additionally, patients who have been previously diagnosed with and treated for hepatocellular carcinoma require continued surveillance for recurrent hepatocellular carcinoma. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
• , E. P., Kaur, H., Hindman, N. M., Al-Refaie, W. B., Arif-Tiwari, H., Cash, B. D., Chernyak, V., Farrell, J., Grajo, J. R., Horowitz, J. M., McNamara, M. M., Noto, R. B., Qayyum, A., Lalani, T., & Kamel, I. R. (2017). ACR Appropriateness Criteria Suspected Liver Metastases. Journal of the American College of Radiology : JACR, 14(5S), S314-S325.
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  Liver metastases are the most common malignant liver tumors. The accurate and early detection and characterization of liver lesions is the key to successful treatment strategies. Increasingly, surgical resection in combination with chemotherapy is effective in significantly improving survival if all metastases are successfully resected. MRI and multiphase CT are the primary imaging modalities in the assessment of liver metastasis, with the relative preference toward multiphase CT or MRI depending upon the clinical setting (ie, surveillance or presurgical planning). The optimization of imaging parameters is a vital factor in the success of either modality. PET/CT, intraoperative ultrasound are used to supplement CT and MRI. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
• , E. P., Qayyum, A., Tamm, E. P., Kamel, I. R., Allen, P. J., Arif-Tiwari, H., Chernyak, V., Gonda, T. A., Grajo, J. R., Hindman, N. M., Horowitz, J. M., Kaur, H., McNamara, M. M., Noto, R. B., Srivastava, P. K., & Lalani, T. (2017). ACR Appropriateness Criteria Staging of Pancreatic Ductal Adenocarcinoma. Journal of the American College of Radiology : JACR, 14(11S), S560-S569.
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  Pancreatic adenocarcinoma is associated with poor overall prognosis. Complete surgical resection is the only possible option for cure. As such, increasingly complex surgical techniques including sophisticated vascular reconstruction are being used. Continued advances in surgical techniques, in conjunction with use of combination systemic therapies, and radiation therapy have been suggested to improve outcomes. A key aspect to surgical success is reporting of pivotal findings beyond absence of distant metastases, such as tumor size, location, and degree of tumor involvement of specific vessels associated with potential perineural tumor spread. Multiphase contrast-enhanced multidetector CT and MRI are the imaging modalities of choice for pretreatment staging and presurgical determination of resectability. Imaging modalities such as endoscopic ultrasound and fluorine-18-2-fluoro-2-deoxy-D-glucose imaging with PET/CT are indicated for specific scenarios such as biopsy guidance and confirmation of distant metastases, respectively. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
• Arif Tiwari, H., Horowitz, J., Kamel, I., Asrani, S., Hindman, N., Kaur, H., McNamara, M., Noto, R., Qayyum, A., & Lalani, T. (2017). Chronic Liver disease. Expert Panel on Gastrointestinal Imaging: ACR Appropriateness Criteria. Journal of the American College of Radiology, 14(5), Supplement, S1-S380.
• Czeyda-Pommersheim, F., Czeyda-Pommersheim, F., Kalb, B. T., Kalb, B. T., Costello, J. R., Costello, J. R., Liau, J., Liau, J., Meshksar, A., Meshksar, A., Arif Tiwari, H., Arif Tiwari, H., Martin, D. R., & Martin, D. R. (2017). MRI in Pelvic Inflammatory Disease: a Pictorial Review. Abdominal Radiology.
• Czeyda-Pommersheim, F., Kalb, B., Costello, J., Liau, J., Meshksar, A., Arif Tiwari, H., & Martin, D. (2017). MRI in pelvic inflammatory disease: a pictorial review. Abdominal radiology (New York), 42(3), 935-950.
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  Pelvic inflammatory disease (PID) is an ascending infection of the female genital tract caused by the spread of bacteria from the vagina to the pelvic reproductive organs and occasionally the peritoneum. The most common causative organisms are sexually transmitted. PID is a significant source of morbidity among reproductive age women both as a cause of abdominal pain and as a common cause of infertility. Its clinical presentation is often nonspecific, and the correct diagnosis may first come to light based on the results of imaging studies. MRI is well suited for the evaluation of PID and its complications due to its superior soft tissue contrast and high sensitivity for inflammation. MRI findings in acute PID include cervicitis, endometritis, salpingitis/oophoritis, and inflammation in the pelvic soft tissues. Acute complications include pyosalpinx, tuboovarian abscess, peritonitis, and perihepatitis. Hydrosalpinx, pelvic inclusion cysts and ureteral obstruction may develop as chronic sequela of PID. The pathophysiology, classification, treatment, and prognosis of PID are reviewed, followed by case examples of the appearance of acute and subclinical PID on MR images.
• Kaur, H., Hindman, N., Al-Refaie, W., Arif Tiwari, H., Cash, B., Chernyak, V., Farrell, J., Grajo, J., Horowitz, J., McNamara, M., Noto, R., Qayyum, A., Lalani, T., & Kamel, I. (2017). Suspected liver metastases. Expert Panel on Gastrointestinal Imaging: ACR Appropriateness Criteria. Journal of the American College of Radiology, 14(5), Supplement, S1-S380.
• Scali, H., Walshe, T., Arif Tiwari, H., Harris, A., & Chang, S. (2017). A Pictorial Review of Hepatobiliary Magnetic Resonance Imaging With Hepatocyte-Specific Contrast Agents: Uses, Findings, and Pitfalls of Gadoxetate Disodium and Gadobenate Dimeglumine. Canadian Association of Radiologists Journal, 68(3), 293-307. doi:10.1016/j.carj.2016.10.008
• Duke, E., Kalb, B., Arif Tiwari, H., Zhongyin, J. D., Gilbertson-Dahdal, D., Keim, S. M., & Martin, D. R. (2016). A systematic review and meta-analysis of diagnostic performance of MRI for evaluation of acute appendicitis. American Journal of Roentgenology.
• Duke, E., Kalb, B., Arif-Tiwari, H., Daye, Z. J., Gilbertson-Dahdal, D., Keim, S. M., & Martin, D. R. (2016). A Systematic Review and Meta-Analysis of Diagnostic Performance of MRI for Evaluation of Acute Appendicitis. AJR. American journal of roentgenology, 206(3), 508-17.
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  A meta-analysis was performed to determine the accuracy of MRI in the diagnosis of acute appendicitis in the general population and in subsets of pregnant patients and children.
• Gimber, L. H., Melville, D., Klauser, A., Witte, R., Arif Tiwari, H., & Taljanovic, M. (2016). Artifacts at Musculoskeletal US: Resident and Fellow Education Feature. Radiographics, 36(2), 479-80. doi:10.1148/rg.2016150200
• Majeed, A., Ullah, W., Hamadani, A., Georgescu, A., & Arif Tiwari, H. (2016). First reported case of peroneal tenosynovitis caused by Coccidioides immitis successfully treated with fluconazole. BMJ Case Reports.
• Petkovska, I., Duke, E., Martin, D. R., Irani, Z., Geffre, C. P., Cragun, J. M., Costello, J. R., Arif-Tiwari, H., Czeyda-Pommersheim, F., Udayasankar, U., & Kalb, B. (2016). MRI of ovarian torsion: Correlation of imaging features with the presence of perifollicular hemorrhage and ovarian viability. European journal of radiology, 85(11), 2064-2071.
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  The purpose of our study is to test for: (a) correlation between the presence of a perifollicular T2-hypointense rim on MRI with the presence of perifollicular hemorrhage on histology; and (b) correlation between this finding and diminished ovarian viability after intra-operative detorsion.
• Petkovska, I., Martin, D. R., Covington, M. F., Urbina, S., Duke, E., Daye, Z. J., Stolz, L. A., Keim, S. M., Costello, J. R., Chundru, S., Arif-Tiwari, H., Gilbertson-Dahdal, D., Gries, L., & Kalb, B. (2016). Accuracy of Unenhanced MR Imaging in the Detection of Acute Appendicitis: Single-Institution Clinical Performance Review. Radiology, 279(2), 451-60.
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  To determine the accuracy of unenhanced magnetic resonance (MR) imaging in the detection of acute appendicitis in patients younger than 50 years who present to the emergency department with right lower quadrant (RLQ) pain.
• Petkovska, I., Martin, D. R., Covington, M. F., Urbina, S., Duke, E., Daye, Z. J., Stolz, L. A., Keim, S. M., Costello, J., Chundru, S., Arif-Tiwari, H., Gilbertson-Dahdal, D., Gries, L., & Kalb, B. (2016). Accuracy of unenhanced MR Imaging in the detection of acute appendicitis: Single institution clinical performance review. Radiology.
• Arif-Tiwari, H., Kalb, B., Chundru, S., Sharma, P., Costello, J., Guessner, R. W., & Martin, D. R. (2015). MRI of hepatocellular carcinoma: an update of current practices. Diagnostic and interventional radiology (Ankara, Turkey), 20(3), 209-21.
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  Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and liver transplantation is the optimal treatment for selected patients with HCC and chronic liver disease (CLD). Accurate selection of patients for transplantation is essential to maximize patient outcomes and ensure optimized allocation of donor organs. Magnetic resonance imaging (MRI) is a powerful tool for the detection, characterization, and staging of HCC. In patients with CLD, the MRI findings of an arterial-enhancing mass with subsequent washout and enhancing capsule on delayed interstitial phase images are diagnostic for HCC. Major organizations with oversight for organ donor distribution, such as The Organ Procurement and Transplantation Network (OPTN), accept an imaging diagnosis of HCC, no longer requiring tissue biopsy. In patients that are awaiting transplantation, or are not candidates for liver transplantation, localized therapies such as transarterial chemoembolization and radiofrequency ablation may be offered. MRI can be used to monitor treatment response. The purpose of this review article is to describe the role of imaging methods in the diagnosis, staging, and follow-up of HCC, with particular emphasis on established and evolving MRI techniques employing nonspecific gadolinium chelates, hepatobiliary contrast agents, and diffusion weighted imaging. We also briefly review the recently developed Liver Imaging Reporting and Data System (LI-RADS) formulating a standardized terminology and reporting structure for evaluation of lesions detected in patients with CLD.
• Becker-Weidman, D., Kalb, B., Mittal, P. K., Harri, P. A., Arif-Tiwari, H., Farris, A. B., Chen, Z., Sungjin, K., & Martin, D. R. (2015). Differentiation of lipid-poor adrenal adenomas from non-adenomas with magnetic resonance imaging: Utility of dynamic, contrast enhancement and single-shot T2-weighted sequences. European journal of radiology, 84(11), 2045-51.
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  To evaluate the utility of dynamic, contrast-enhanced magnetic resonance imaging (MRI) in combination with single-shot T2-weighted (ssT2) sequences in the differentiation of lipid-poor adrenal adenomas from non-adenomas.
• Chundru, S., Kalb, B., Arif-Tiwari, H., Sharma, P., Costello, J., & Martin, D. R. (2015). MRI of diffuse liver disease: the common and uncommon etiologies. Diagnostic and interventional radiology (Ankara, Turkey), 19(6), 479-87.
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  Diffuse liver disease, including all causes of chronic liver disease, affects tens of millions of people worldwide. There is a growing need for diagnostic evaluation as treatments become more readily available, particularly for viral liver disease. Magnetic resonance imaging (MRI) provides unique capabilities for noninvasive characterization of liver tissue that rival or surpass the diagnostic utility of liver biopsies. There has been incremental improvement in the use of standardized MRI sequences, acquired before and after administration of contrast for the evaluation of diffuse liver disease, and this includes study of the liver parenchyma and blood supply. More recent developments have led to methods for quantifying important liver metabolites, including fat and iron, and liver fibrosis, which is the hallmark for chronic liver disease. In this study, we review the MRI techniques and diagnostic features associated with common and uncommon etiologies of diffuse liver diseases, including processes that lead to abnormal perfusion (e.g. Budd-Chiari syndrome, congestive hepatomegaly), deposition diseases (e.g. fatty liver, hemochromatosis, Wilson's disease), and abnormalities that are related to inflammation and fibrosis (e.g. primary sclerosing cholangitis, sarcoidosis).
• Goyal, U., Arif, H., Stea, B., Kim, Y., Goyal, U., & Arif, H. (2015). Ultrasound-Aided Electronic Brachytherapy for Nonmelanomatous Skin Cancers. Brachytherapy, 14, S45-S46. doi:10.1016/j.brachy.2015.02.267
• Goyal, U., Kim, Y., Arif Tiwari, H., Witte, R., & Stea, B. (2015). A pilot study of ultrasound-guided electronic brachytherapy for skin cancer. J Contemp Brachytherapy, 7(5), 374-80. doi:10.5114/jcb.2015.55538
• Kulvantunyou, N., Pandit, V., Moutamn, S., Inaba, K., Chouliaras, K., DeMoya, M., Naraghi, L., Kalb, B., Arif Tiwari, H., Sravanthi, R., Joseph, B., Gries, L., Tang, A. L., & Rhee, P. (2015). A multi-institution prospective observational study of small bowel obstruction: Clinical and computerized tomography predictors of which patients may require early surgery. Journal of Trauma Acute Care Surgery, 79(3), 393-398.
• Lalwani, N., Mannelli, L., Ganeshan, D. M., Shanbhogue, A. K., Dighe, M. K., Tiwari, H. A., Maximin, S., Monti, S., Ragucci, M., & Prasad, S. R. (2015). Uncommon pancreatic tumors and pseudotumors. Abdominal imaging, 40(1), 167-80.
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  A heterogeneous group of uncommon neoplastic and non-neoplastic pancreatic pathologies exists that can mimic pancreatic adenocarcinoma. These "imitators" are unique and may demonstrate characteristic clinical and imaging features. Imaging characteristics of some of these diverse lesions are not well described in the literature, and erroneous diagnoses of these entities as pancreatic carcinoma may be responsible for unnecessary surgeries. Knowledge of these selected pancreatic pathologies is essential to facilitate optimal patient management.
• Malangone, S., Patel, H., Kurtin, S., Arif Tiwari, H., & Elquza, E. (2015). Grand Rounds: Multidisciplinary Management of the Patient with Metastatic Colorectal Adenocarcinoma. J Adv Pract Oncol, 6(2), 144–152.
• Taljanovic, M., Melville, D., Klauser, A., Latt, D., Arif Tiwari, H., Gao, L., & Witte, R. (2015). Advances in Lower Extremity Ultrasound. Current Radiology Reports, 3(6). doi:https://doi.org/10.1007/s40134-015-0100-5
• Arif Tiwari, H., Kalb, B., Funk, J., Martin, D. R., & Twiss, C. (2014). Addition of a defecography phase to a dynamic pelvic MRI enhances detection and visualization of pelvic organ prolapse. Neurourol Urodyn, 33(2), 232.
• Arif Tiwari, H., Kalb, B., Funk, J., Martin, D. R., & Twiss, C. (2014). Addition of a defecography phase to dynamic pelvic MRI enhances detection and visualization of pelvic organ prolapse. J Urol, 191(4), (suppl):e782. doi:http://dx.doi.org/10.1016/j.juro.2014.02.2141
• Chundru, S., Kalb, B., Arif-Tiwari, H., Sharma, P., Costello, J., & Martin, D. R. (2014). MRI of diffuse liver disease: characteristics of acute and chronic diseases. Diagnostic and interventional radiology (Ankara, Turkey), 20(3), 200-8.
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  Diffuse liver disease, including chronic liver disease, affects tens of millions of people worldwide, and there is a growing need for diagnostic evaluation as treatments become more readily available, particularly for viral liver diseases. Magnetic resonance imaging (MRI) provides unique capabilities for noninvasive characterization of the liver tissue that rival or surpass the diagnostic utility of liver biopsies. There has been incremental improvement in the use of standardized MRI sequences, acquired before and after administration of a contrast agent, for the evaluation of diffuse liver disease and the study of the liver parenchyma and blood supply. More recent developments have led to methods for quantifying important liver metabolites, including lipids and iron, and liver fibrosis, the hallmark of chronic liver disease. Here, we review the MRI techniques and diagnostic features associated with acute and chronic liver disease.
• Costello, J. R., Kalb, B., Chundru, S., Arif, H., Petkovska, I., & Martin, D. R. (2014). MR imaging of benign and malignant biliary conditions. Magnetic resonance imaging clinics of North America, 22(3), 467-88.
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  MR imaging is a noninvasive, radiation-free imaging method for evaluation of the biliary system. Continued advancements in MR imaging system hardware and sequence design, coupled with novel gadolinium chelate agents, allow for a detailed evaluation of the bile ducts and surrounding soft tissues. New hepatocyte-specific contrast agents may hold utility in the anatomic and functional evaluation of bile duct injury. MR imaging is also the imaging method of choice for bile duct tumor diagnosis, staging, and presurgical planning. Familiarity with the proper methodology of MR image acquisition and interpretation is critical for optimized diagnostic assessment.
• Lalwani, N., Mannelli, L., Ganeshan, D., Shanbhogue, K. A., Dighe, M., Arif Tiwari, H., Maximin, S., Monti, S., Ragucci, M., & Srinivasa, P. R. (2014). Uncommon pancreatic tumors and pseudotumors. Abdominal Imaging, 40(1).
• Arif Tiwari, H., Kalb, B., Chundru, S., Costello, J., Ghishan, F., Sauer, C. G., Goldschmid, S., & Martin, D. R. (2013). The diagnostic role of magnetic resonance enterography in Crohn’s disease: an updated review of techniques, interpretation and application. Applied Radiology, 42(12), 5-15.

Proceedings Publications

• Bilgin, A., Altbach, M. I., Martin, D. R., Arif Tiwari, H., Shareef, F., Unger, W., & Umapathy, L. (2019, May). A Cascaded Residual UNET for Fully Automated Segmentation of Prostate and Peripheral Zone in T2-weighted 3D Fast Spin Echo Images. In Proc. of 2019 Annual Meeting of the ISMRM, Montreal, QC, Canada.
• Altbach, M. I., Martin, D. R., Arif Tiwari, H., Johnson, K., Bilgin, A., & Li, Z. (2018, June). High-resolution 3D T1 mapping of the prostate with an efficient inversion-recovery radial FLASH. In 2018 Meeting of the International Society for Magnetic Resonance in Medicine.

Presentations

• Pedapati, S., Murugapandian, S., Arif Tiwari, H., & Thajudeen, B. (2023, Fall). Truly a catastrophe: A case of severe antiphospholipid syndrome in the setting of Lupus. ASN National Meeting Kidney Week. Philadelphia, PA.
• Arif Tiwari, H., De La Rosa, J., Min, A., Coull, B., Valenzuela, C., Kelso, A., Fain, M., Glas, K., & Abecassis, M. (2023, November). Spurring Success for Women in Medicine & Science (SSWIMS). AAMC Annual Meeting. Seattle Washington.
• Arif Tiwari, H., Vedantham, S., Trujillo, M., Elcic, L., Rounseville, B., & Greenhill, M. (2023, April). Implementation of an abbreviated venous duplex ultrasound protocol for detection of deep vein thrombus in hospitalized COVID-19 (+) patients. Annual Meeting of the American Roentgen Ray Society (ARRS 2023). Honolulu, HI: American Roentgen Ray Society.
• Duhancioglu, G., Gupta, K., Reynolds, C., Vedantham, S., & Arif Tiwari, H. (2023, April). Multiparametric MRI characterization for diagnosing acute cholecystitis.. 2023 American Roentgen Ray Society (ARRS) Annual Meeting.
• Duhancioglu, G., Reynolds, C., & Arif Tiwari, H. (2023, April). .  The Traveling Gallstone
  . 2023 American Roentgen Ray Society (ARRS) Annual Meeting.
• Gupta, K., & Arif Tiwari, H. (2023, April). MR Imaging of early parenchymal complications of renal allografts: Added value of DWI to Dynamic Contrast Enhanced MR and T2W Images
  . 2023 American Roentgen Ray Society (ARRS) Annual Meeting.
• Reynolds, C., Duhancioglu, G., & Arif Tiwari, H. (2023, April). Tuberous Sclerosis: Radiologic Manifestations and Recommended Imaging Surveillance
  . 2023 American Roentgen Ray Society (ARRS) Annual Meeting.
• Greenhill, M., & Arif Tiwari, H. (2022). Benign Prostatic Hyperplasia: Post-Treatment MRI Findings. American Roentgen Ray Society Annual Meeting 2022.
• Greenhill, M., & Arif Tiwari, H. (2022, March). Review of Surgical Technique and Correlative MRI Imaging of BPH Interventions. Society of Abdominal Radiology. Phoenix.
• Anthony, M., & Arif Tiwari, H. (2021, October). Spectrum of MR Imaging Findings of Gallstone-related Complications. Society of Advanced Body Imaging.
• Anthony, M., & Arif Tiwari, H. (2021, October). Traveling Gallstones: Spectrum of MR Imaging Findings of Gallstone-related Complications. Society of Advanced Body Imaging.
• Struycken, L., & Arif Tiwari, H. (2021, April). Acute Hepatobiliary Emergencies: Spectrum of MR Imaging. American Roentgen Ray Society.
• Al Bayati, S., Dufenberg, M., Reddy, D., Lalwani, N., Lall, C., & Arif Tiwari, H. (2020, May). Spectrum of Magnetic Resonance Imaging in Complicated Choledochal Cysts. Medical Imaging Annual Research Day Online. Tucson, AZ: University of Arizona, College of Medicine.
• Al Bayati, S., Nolte, D., Kalb, B., Sowby, J., Reddy, D., Lalwani, N., Lall, C., & Arif Tiwari, H. (2020, May). Role of MR imaging in accurate diagnosis of primary peritoneal serous carcinoma. Medical Imaging Annual Research Day Online. Tucson, AZ: University of Arizona, College of Medicine.
• Arif Tiwari, H. (2020, August). Imaging of Pelvic Anatomy. Life cycle speakerCollege of Medicine, University of Arizona.
• Arif Tiwari, H., Chartier, S., Tiwari, T., Kalb, B., & Saranathan, M. (2020, August). Effect of continuous table movement (CTM) on fat saturation quality in T2 weighted imaging. International Society for Magnetic Resonance in Medicine.
• Arif Tiwari, H., Kalb, B. T., Vedantham, S., & Spicer, C. (2020, March). Diagnostic Performance of MR Imaging in the Detection of Ovarian Torsion. SAR 2020 Annual Scientific Meeting and Educational Course. Maui, HI: Society of Abdominal Radiology.
• Garnica, J., & Arif Tiwari, H. (2020, July). Imaging methods to diagnose ovarian torsion. FRONTERA- Closing Ceremony online. Tucson, AZ.
• Larson, M., Gudi, H., Bozdogan, E., Khriess, M., Zarvos, Y., Shroff, R., Riall, T., & Arif Tiwari, H. (2020, November). Morphological and Functional Magnetic Resonance Imaging (MRI) evaluation of Pancreatic Ductal Adenocarcinoma (PDAC): Diagnosis, Treatment Response, and Prognosis. University of Arizona Cancer Center Annual Scientific RetreatUniversity of Arizona Cancer Center.
• Marr, K., Arif Tiwari, H., Gard, J., Warfel, N., Nagle, R., & Cress, A. (2020). Cancer cell invasion through a complex and dynamic smooth muscle microenvironment. American Society for Cell Biology.
• Marr, K., Arif Tiwari, H., Ingabire, N., Wang, M., Gard, J., Garcia, J., & Cress, A. (2020, March). Smooth muscle invasion by prostate cancer requires laminin-binding integrins. AACR Advances in Prostate Cancer Research 2020. Denver, CO.
• Marr, K., Arif Tiwari, H., Manzi, N., Wang, M., Gard, J., Warfel, N., Garcia, J., & Cress, A. (2020, Fall). Laminin-binding integrins are required for cancer cell invasion through a complex and dynamic smooth muscle microenvironment.. American Society for Cell Biology Cell Bio Virtual 2020 - an Online ASCB|EMBO Meeting.
• Muse, A., Sloss, M., Shah, S., Sandberg, D., Wong, A., Lwin, A., Hinkel, C., Arif Tiwari, H., & Tzou, D. (2020, October). Understanding the Barriers to Implementing and Achieving Low-Dose Computerized Tomography for Patients with Nephrolithiasis. Western Section of the American Urological Association (WSAUA).
• Pollack, G., Arif Tiwari, H., Chartier, S., Vedantham, S., Funk, J., & Twiss, C. (2020, February). Comparison of magnetic resonance defecography grading with pop‐q staging and baden‐walker grading in the evaluation of female pelvic organ prolapse. SUFU. Scottsdale, AZ.
• Spicer, C., Vedantham, S., Kalb, B., & Arif Tiwari, H. (2020, March). Diagnostic Performance of MR Imaging in the Detection of Ovarian Torsion. Society of Abdominal Radiology. Maui, HI.
• Spicer, C., Vedantham, S., Kalb, B., & Arif Tiwari, H. (2020, May). Diagnostic Performance of MR Imaging in the Detection of Ovarian Torsion. Medical Imaging Annual Research Day Online. Tucson, AZ: University of Arizona, College of Medicine.
• Zapien, A., & Arif Tiwari, H. (2020, July). Understanding the primary peritoneal cancer and peritoneal metastasis from ovarian cancer using advanced magnetic resonance imaging. FRONTERA- Closing Ceremony online. Tucson, AZ: College of Medicine, University of Arizona.
• Al Bayati, S., Dufenberg, M., Reddy, D., Lalwani, N., Lall, C., & Arif Tiwari, H. (2019, December). Spectrum of Magnetic Resonance Imaging in Complicated Choledochal Cysts. Radiologic Society of North America. Chicago.
• Al Bayati, S., Nolte, D., Kalb, B., Sowby, J., Reddy, D., Lalwani, N., Lall, C., & Arif Tiwari, H. (2019, December). Role of MR imaging in accurate diagnosis of primary peritoneal serous carcinoma. Radiologic Society of North America. Chicago.
• Arif Tiwari, H. (2019, February). Data Blitz- Novel MR-directed Ultrasound-guided (MRdUSg) Prostate Biopsy Technique. Annual Research Day. Tucson: University of Arizona, College of Medicine.
• Arif Tiwari, H. (2019, February). Women in Medicine- Panelist. American Medical Women’s Association. Tucson: University of Arizona, College of Medicine.
• Arif Tiwari, H., & Vedantham, S. (2019, June/Summer). Advances in Multiparametric MRI and Fusion Prostate Biopsy for Prostate Adenocarcinoma: A Changing Paradigm.. Prostate Cancer Working Group Annual Meeting, University of Arizona Cancer Center. Tucson, AZ: University of Arizona Cancer Center.
• Arif Tiwari, H., Warfa, M., Goyal, A., Burke, L., Kielar, A., & Lalwani, N. (2019, December). Should We Use Oral Contrast in CT Imaging?. Radiologic Society of North America.
• Gopireddy, D., Jayagurunathan, U., Arif Tiwari, H., Lall, C., Kalb, B., Martin, D., & Sharma, S. (2019, December). Twists, Turns, and Flames on MRI of the Adnexa: Pearls & Pitfalls in Evaluating Adnexal Emergencies. Radiologic Society of North America. Chicago.
• Marr, K. D., Arif Tiwari, H., Hinton, J. P., Nagle, R. B., Martin, D. R., & Cress, A. E. (2019, November). Characterizing the Molecular Tumor Landscape in Prostate Cancer Patients. APSA Western Regional Meeting. Loma Linda.
• Sharma, S., Nwachukwu, C., Gopireddy, D., Lall, C., Elsayes, K., Arif Tiwari, H., & Kassam, Z. (2019, December). Ano-Rectal Tumors: Radiologist to the Rescue. Radiologic Society of North America. Chicago.
• Spicer, C., Arif Tiwari, H., Martin, D., & Kalb, B. (2019, May). Performance of non-contrast magnetic resonance pulmonary angiogram to exclude pulmonary thromboembolism in pregnant patients.. American Roentgen Ray Society. Honolulu.
• Spicer, C., Kalb, B., Martin, D., & Arif Tiwari, H. (2019, May). Diagnostic accuracy of shear wave elastography combined with standard ultrasound imaging in thyroid nodule evaluation. American Roentgen Ray Society. Honolulu.
• Spicer, C., Spicer, C., Kalb, B. T., Kalb, B. T., Martin, D. R., Martin, D. R., Vedantham, S., Vedantham, S., Arif Tiwari, H., & Arif Tiwari, H. (2019, May). Diagnostic accuracy of shear-wave elastography combined with standard ultrasound imaging in thyroid nodule evaluation.. Annual Meeting of the American Roentgen Ray Society (ARRS 2019). Honolulu, HI: American Roentgen Ray Society (ARRS 2019).
• Umapathy, L., Unger, E., Shareef, F., Arif Tiwari, H., Martin, D., Altbach, M., & Bilgrin, A. (2019, May). A Cascaded Residual UNET for Fully Automated Segmentation of prostate and peripheral zone in T2-weighted 3D Fast Spin Echo Images. International Society for Magnetic Resonance in Medicine. Montreal, Canada.
• Arif Tiwari, H. (2018, December). Genetically Determined Integrin α6 Variant Converts Muscle Invasive Prostate Cancer Networks into Non-Invasive Cohesive Clusters. The American Society for Cell Biology Annual Meeting. San Diego, CA.
• Arif Tiwari, H. (2018, June). High-resolution 3D T1 mapping of the prostate with an efficient inversion-recovery radial FLASH pulse sequence. International Society for Magnetic Resonance in Medicine Meeting. Melbourne, Australia: ISMRM.
• Arif Tiwari, H., Martin, D., & Kalb, B. (2018, March). MR directed US guided (MRdUSg) Fusion Prostate biopsy- Improved and accurate detection, localization and staging of Prostate Adenocarcinoma (PCa). Society of Abdominal Radiology. Phoenix, AZ.
• Frankl, J., Kalb, B., Liau, J., Gopireddy, D., Bisla, J., & Arif Tiwari, H. (2018, November). Cholangiocarcinoma: Role of Magnetic Resonance Imaging in diagnosis, staging and management. Radiologic Society of North America Annual Meeting. Chicago, IL: RSNA.
• Abdelaziz, A., Kalb, B. T., Liau, J., Meshksar, A., Czeyda-Pommersheim, F., Arif Tiwari, H., Martin, D. R., & Costello, J. R. (2017, March). Magnetic Resonance Findings of Uterine Sarcoma. SAR. Hollywood, CA.
• Hannallah, J., Meshksar, A., Kalb, B. T., Czeyda-Pommersheim, F., Liau, J., Arif Tiwari, H., Martin, D. R., & Costello, J. R. (2017, March). Accurate Magnetic Resonance Imaging (MRI) Diagnosis of Ascending Cholangitis. Society of Abdominal Radiology. Hollywood, CA.
• Lin, F., Arif Tiwari, H., Kalb, B., Funk, J., & Twiss, C. (2017, March). Dynamic MRI Defecography Phase in the Evaluation of Pelvic Organ Prolapse and Correlation with Physical Exam Findings. SUFU Society of Urodynamics, Female Pelvic Medicine. San Francisco.
• Lin, F., Arif Tiwari, H., Kalb, B., Funk, J., & Twiss, C. (2017, October). Dynamic MRI Defecography Phase in the Evaluation of Pelvic Organ Prolapse and Correlation with Physical Exam Findings. AUA American Urological Association's Annual Meeting. San Francisco.
• Arif Tiwari, H., Costello, J. R., Funk, J., Kalb, B. T., Martin, D. R., Meshksar, A., Petkovska, I., Czeyda-Pommersheim, F., & Twiss, C. O. (2016, April). Comparative Evalution of Defecography Phase to Non-Defecography Valsalva Maneuver in Dynamic Pelvic Floor MRI. Canadian Association of Radiologists, 79th Annual Scientific Meeting (ASM). Montreal, QC.
• Hershman, M., Kalb, B. T., Petkovska, I., Arif Tiwari, H., Czeyda-Pommersheim, F., Duke, E., Meshkar, A., Martin, D. R., & Costello, J. R. (2016, MARCH). MRI Diagnosis of Pheochromocytomas and Paragangliomas. SAR 2016.
• Ho, P., Hur, S., Kalb, B. T., Petkovska, I., Arif Tiwari, H., Czeyda-Pommersheim, F., Martin, D. R., Costello, J. R., Ho, P., Hur, S., Kalb, B. T., Petkovska, I., Arif Tiwari, H., Czeyda-Pommersheim, F., Martin, D. R., & Costello, J. R. (2016, MARCH). Comparison of Contrast Enhanced MRI versus Hepatobiliary Scintigraphy in the Diagnosis of Chronic Cholecystitis. SAR 2016.
• Ho, P., Kalb, B. T., Petkovska, I., Arif Tiwari, H., Czeyda-Pommersheim, F., Martin, D. R., & Costello, J. R. (2016, June). Comparison of Contrast Enhanced MRI versus Hepatobiliary Scintigraphy in the Diagnosis of Chronic Cholecystitis. Department of Medical Imaging Research Day.
• Patel, V., Kalb, B. T., Arif Tiwari, H., Czeyda-Pommersheim, F., Petkovska, I., Martin, D. R., & Costello, J. R. (2016, November). Accurate Magnetic Resonance Imaging Diagnosis of Splenic Pathology. RSNA.
• Sowby, J., Kalb, B. T., Petkovska, I., Arif Tiwari, H., Czeyda-Pommersheim, F., Duke, E., Meshkar, A., Martin, D. R., & Costello, J. R. (2016, MARCH). Accurate Diagnosis of Fibromas and Fibrothecomas using Advanced MRI Techniques.. SAR 2016.
• Arif Tiwari, H., Sharma, P., Kalb, B., Arif-Tiwari, H., Petkovska, I., Czeyda-Pommersheim, F., Chundru, S., Woodhead, G., & Martin, D. R. (2015, December). Magnetic Resonance Angiography of the Lower Extremity Arterial Vasculature. RSNA 2015.
• Irani, Z., Petkovska, I., Kalb, B. T., Geffre, C., Cragun, J. M., Arif Tiwari, H., Czeyda-Pommersheim, F., & Martin, D. R. (2015, MARCH). MRI’s tale of Ovary Twist.. RSNA.
• Petkovska, I., Irina, Z., Kalb, B. T., Geffre, C., Cragun, J. M., Arif Tiwari, H., Czeyda-Pommersheim, F., & Martin, D. R. (2015, MARCH). The “Onyx Rim” sign in pelvic MRI: Perifollicular Hemorrhage as a Potential Predictor of viability in the setting of ovarian torsion.. RSNA2015.
• Petkovska, I., Kalb, B., Hur, J., Ott, P., Lata, K., Dherange, P., Oliva, I., Urbina, S., Arif Tiwari, H., Chundru, S., Costello, J., & Martin, D. R. (2015, June). MRI in Patients with Cardiac Implantable Electronic Devices: Our Institutional Experience. ISMRM 2015.
• Petkovska, I., Martin, D. R., Arif Tiwari, H., Czeyda-Pommersheim, F., & Hur, J. (2015, March). MR imaging of common ED renal pathologies.. RSNA 2015.
• Petkovska, I., Martin, D. R., Kalb, B. T., Costello, J. R., Arif Tiwari, H., & Chundru, S. (2015, March). Non-contrast MRI accuracy for the evaluation of suspected acute appendicitis in patients ≤ 40 years. SAR 2015.
• Petkovska, I., Martin, D. R., Kalb, B. T., Costello, J. R., Arif Tiwari, H., & Chundru, S. (2015, March). Staging of Gastrointestinal Malignancies: Converting from CT to MRI. SAR 2015.
• Arif Tiwari, H., Kalb, B. T., Funk, J., Twiss, C. O., & Martin, D. R. (2014, February). Addition of a Defecography Phase to Dynamic Pelvic MRI Enhances Detection and Visualization of Pelvic Organ Prolapse. Society of Urodynamics, Female Pelvic Medicine, and Urogenital Reconstruction Meeting. Miami, FL.
• Arif Tiwari, H., Kalb, B. T., Twiss, C. O., Funk, J., & Martin, D. R. (2014, May). Addition of a Defecography Phase to Dynamic Pelvic MRI Enhances Detection and Visualization of Pelvic Organ Prolapse. American Urological Association Meeting. Orlando, FL.
• Chundru, S., Kalb, B. T., Arif Tiwari, H., Sharma, P., Costello, J. R., & Martin, D. R. (2014, November). MRI of diffuse liver disease: the common and uncommon etiologies. RSNA. Chicago, IL.
• Gimber, L. H., Melville, D. M., Klauser, A. S., Witte, R. S., Arif Tiwari, H., & Taljanovic, M. S. (2014, November). Artifacts at Musculoskeletal US. RSNA Annual Meeting. Chicago, IL.
• Arif Tiwari, H., Becker-Weidman, D., Kalb, B., & Martin, D. R. (2013, April). Differentiating Lipid Poor Adrenal Adenomas and Malignant Adrenal Neoplasms by a Combination of Dynamic Contrast Enhanced T1-Weighted 3D Gradient Echo Sequences and Single Shot T2-Weighted Images: Preliminary Results. International Society for Magnetic Resonance in Medicine. Salt Lake City, UT.
• Arif Tiwari, H., Covington, M., Urbina, S., Krupinski, E., Stolz, L., Martin, D. R., Chundru, S., Costello, J., & Kalb, B. (2013, October). Diagnostic Performance of Noncontrast Abdominopelvic MRI for the Evaluation of Suspected Acute Appendicitis in Patients < 40 Years Old: Cost considerations and impact on emergency department patient throughput. Society of Computed Body Tomography & Magnetic Resonance. Tucson, AZ.
• Arif Tiwari, H., Covington, M., Urbina, S., Krupinski, E., Stolz, L., Martin, D. R., Gilbertson-Dahdal, D., Desoky, S. M., & Kalb, B. (2013, October). Diagnostic Performance of Noncontrast Abdominopelvic MRI for the Evaluation of Suspected Acute Appendicitis in Patients < 40 Years Old. Society of Computed Body Tomography & Magnetic Resonance. Tucson, AZ.
• Arif Tiwari, H., Kalb, B., & Martin, D. R. (2013, April). Autoimmune Pancreatitis Revisited: MR Imaging Characteristics and Differentiating Features from Pancreatic Carcinoma. International Society for Magnetic Resonance in Medicine. Salt Lake City, UT.
• Arif Tiwari, H., Kalb, B., & Martin, D. R. (2013, April). MR Imaging of Infiltrative Hepatocellular Carcinoma: Characterization of Imaging Features and Tumor Conspicuity. American Roentgen Ray Society. Washington, D.C..
• Costello, J. R., Schreibmann, E., Cortopassi, F., Sharma, P., Oliva, I., Salman, K., Chundru, S., Arif Tiwari, H., Fox, T., Kalb, B. T., & Martin, D. R. (2013, October). Quantitative Measurement of Pulmonary Biomechanics with MRI Lung Volumetry. Society of Computed Body Tomography & Magnetic Resonance. Tucson, AZ.
• Kumar, S., Arif Tiwari, H., Costello, J., Chundru, S., Kalb, B., Rilo, H., Gruessner, R., & Martin, D. R. (2013, October). The Role of MRI in Islet Cell Transplantation. Society of Computed Body Tomography & Magnetic Resonance. Tucson, AZ.
• Lalwani, N., Shanbhogue, K., Arif Tiwari, H., & Srinivas, P. (2013, November). H Mimics and Confounders in Abdominal Imaging. RSNA. Chicago, IL.
• Arif Tiwari, H., Becker-Weidman, D., Kalb, B., & Martin, D. R. (2012, December). Utility of Single Shot T2W Images and Dynamic Contrast Enhanced MRI in Differentiating Atypical Adrenal Adenomas and Malignant Adrenal Neoplasms. RSNA Annual Meeting. Chicago, IL.
• Arif Tiwari, H., Kalb, B., Funk, J., Twiss, C., & Martin, D. R. (2012, December). Defecography Phase in Dynamic Pelvic Floor MRI: Is There an Added Advantage?. RSNA Annual Meeting. Chicago, IL.
• Arif Tiwari, H., Kalb, B., Sarmiento, J. M., & Martin, D. R. (2012, December). Spectrum of Magnetic Resonance Imaging Features of Autoimmune Pancreatitis: A Pictoral Essay. RSNA Annual Meeting. Chicago, IL.

Poster Presentations

• Marr, K. D., Arif Tiwari, H., Hinton, J. P., Nagle, R. B., Martin, D. R., & Cress, A. E. (2019, April). Retrospective correlation of ultrasound-guided prostate biopsy and multiparametric MRI with tumor pathology. ARCS Scholar Awards Banquet. Phoenix.
• Marr, K. D., Arif Tiwari, H., Hinton, J. P., Nagle, R. B., Martin, D. R., & Cress, A. E. (2019, October). Characterizing the Molecular Tumor Landscape in Prostate Cancer Patients. ACP Arizona Chapter Annual Meeting. Tucson.
• Anderson, J., Kalb, B. T., Liau, J., Meshksar, A., Czeyda-Pommersheim, F., Arif Tiwari, H., Martin, D. R., & Costello, J. R. (2017, March). MRI Evaluation of Ectopic Pregnancies. SAR.
• Austen, T., Czeyda-Pommersheim, F., Meshksar, A., Kalb, B. T., Liau, J., Arif Tiwari, H., Martin, D. R., & Costello, J. R. (2017, March). Magnetic Resonance and Computed Tomography Imaging in the Accurate Diagnosis of Internal Hernias. SAR. Hollywood, CA.
• Hansra, H., Kalb, B. T., Petkovska, I., Czeyda-Pommersheim, F., Arif Tiwari, H., Martin, D. R., & Costello, J. R. (2016, November). Accurate Diagnosis of Acute and Chronic Cholecystitis using Magnetic Resonance Imaging. RSNA.
• Harms, C., Kalb, B. T., Martin, D. R., Czeyda-Pommersheim, F., Petkovska, I., Arif Tiwari, H., & Costello, J. R. (2016, November). Imaging Features of Gestational Trophoblastic Disease. RSNA.
• Johnston, S., Kalb, B. T., Petkovska, I., Martin, D. R., Arif Tiwari, H., Czeyda-Pommersheim, F., & Costello, J. R. (2016, November). MRI Diagnosis of Endometriosis. RSNA.
• Liu, A., Kalb, B. T., Arif Tiwari, H., Czeyda-Pommersheim, F., Petkovska, I., Martin, D. R., & Costello, J. R. (2016, Novemeber). Identification of Atypical Presentation of Pancreatic Neuroendocrine Tumor (NET).. RSNA.
• Taylor, P., Kalb, B. T., Arif Tiwari, H., Czeyda-Pommersheim, F., Petkovska, I., Martin, D. R., & Costello, J. R. (2016, November). Accurate Diagnosis of Lipid Rich and Lipid Poor Angiomyolipomas. RSNA.
• Costello, J., Kalb, B., Chundru, S., Arif Tiwari, H., Salman, K., Cortopassi, F., & Martin, D. R. (2013, November). MRI Diagnosis of Inflammatory Pseudotumor. RSNA Annual Meeting. Chicago, IL.
• Covington, M., Urbina, S., Stolz, L., Martin, D. R., Gilbertson-Dahdal, D., Desoky, S. M., Arif Tiwari, H., & Kalb, B. (2013, November). Diagnostic Performance of Noncontrast Abdominopelvic MRI for the Evaluation of Suspected Acute Appendicitis in Patients < 40 Years Old. RSNA Annual Meeting. Chicago, IL.
• Duke, E., Kalb, B., Chundru, S., Arif Tiwari, H., Martin, D. R., & Costello, J. (2013, November). Magnetic Resonance Imaging of Retroperitoneal Tumors: A Comprehensive Pictorial Review.. RSNA Annual Meeting. Chicago, IL.

Creative Productions

• Arif Tiwari, H. (2020. Approach to Abdominal MRI. Video recording for MRI technologistUniversity of Arizona, College of Medicine.
• Arif Tiwari, H. (2020. FRONTERA (Focusing Research on the Border Area program). Summer internshipUniversity of Arizona, College of Medicine.
• Arif Tiwari, H. (2020. MR Defecography: How we do it- Tips and Tricks. Video recording for MRI technologistUniversity of Arizona, College of Medicine.

Others

• Martin, D. R., Czeyda-Pommersheim, F., Arif Tiwari, H., Cragun, J. M., Geffre, C., Kalb, B. T., Petkovska, I., & Irani, Z. (2015, MARCH). MRI’s tale of Ovary Twist.. Abstract; RSNA.
• Petkovska, I., Irina, Z., Kalb, B. T., Geffre, C., Cragun, J. M., Arif Tiwari, H., Czeyda-Pommersheim, F., & Martin, D. R. (2015, MARCH). The “Onyx Rim” sign in pelvic MRI: Perifollicular Hemorrhage as a Potential Predictor of viability in the setting of ovarian torsion.. Abstract; RSNA2015.
• Arif Tiwari, H. (2020, January). Distinguished Reviewer Acknowledgements. Abdom Radiol.
• Arif Tiwari, H. (2019, January). Report from the pancreatic ductal adenocarcinoma disease focused panel. Abdom Radiol.
• Arif Tiwari, H. (2019, January). SAR DFP on pelvic floor dysfunction: annual report. Abdom Radiol.
• Martin, D., Kalb, B., Arif Tiwari, H., Costello, J., Chundru, S., & Petkovska, I. (2016, April). CPI MRI Self-Assessment Module. American College of Radiology.
• Irani, Z., Petkovska, I., Kalb, B. T., Geffre, C., Cragun, J. M., Arif Tiwari, H., Czeyda-Pommersheim, F., & Martin, D. R. (2015, MARCH). MRI’s tale of Ovary Twist.. Abstract; RSNA.