Srinivasan Vedantham

Interests

Teaching

My teaching interests are to provide didactic lectures in Medical Imaging Physics for Residents and Fellows, to provide graduate education on x-ray imaging modalities including radiography, mammography, fluoroscopy, tomosynthesis and computed tomography (CT), and to provide continuing education courses through professional organizations.

Research

My research interests are in the design, development and clinical translation of novel x-ray imaging systems and imaging techniques with particular focus on oncological and interventional imaging. Along with my collaborators and colleagues, I have made contributions to breast cancer imaging including small-field digital mammography for stereotactic core-biopsies, full-field digital mammography and digital breast tomosynthesis. Currently, I am working on developing advanced tomographic techniques and systems for breast imaging and its clinical translation. This design, development and clinical translation oriented research is funded by the National Institutes of Health. I also conduct research in interventional imaging with a focus on developing advanced detector technology.

Courses

Scholarly Contributions

Chapters

• Vedantham, S. (2018). Tissue Substitute Materials for Diagnostic X-ray Imaging. In Handbook of X-ray Imaging (Russo P, Ed.)(pp 1107-1132). Boca Raton, FL: Taylor & Francis Group, CRC Press.
• Karellas, A., & Vedantham, S. (2017). The Breast X-ray Imaging Continuum – Mammography, Digital Breast Tomosynthesis and Cone-beam Breast Computed Tomography. In Essentials: Dedicated Cone-beam Breast Computed Tomography (O’Connell AM, Ed.)(pp 9-13). Pittsford, NY: Imaging Science Today, LLC.
• Vedantham, S., Karellas, A., & Vijayaraghavan, G. R. (2017). Dedicated Cone-beam Breast Computed Tomography versus. Digital Breast Tomosynthesis. In Essentials: Dedicated Cone-beam Breast Computed Tomography (O’Connell AM, Ed.)(pp 78-93). Pittsford, NY: Imaging Science Today, LLC.

Journals/Publications

• Arif-Tiwari, H., Twiss, C. O., Lin, F. C., Funk, J. T., Vedantham, S., Martin, D. R., & Kalb, B. T. (2019). 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. doi:10.1067/j.cpradiol.2018.08.005
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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).
• Deng, L., Yasar, S., Ahmed, M. F., Jayarathna, S., Feng, P., Wei, B., Vedantham, S., Karellas, A., & Cho, S. H. (2019). Investigation of transmission computed tomography (CT) image quality and x-ray dose achievable from an experimental dual-mode benchtop x-ray fluorescence CT and transmission CT system. Journal of X-ray science and technology, 27(3), 431-442. doi:10.3233/XST-180457
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  To investigate the image quality and x-ray dose associated with a transmission computed tomography (CT) component implemented within the same platform of an experimental benchtop x-ray fluorescence CT (XFCT) system for multimodal preclinical imaging applications.
• Kotecha, H. M., Lo, H. S., Vedantham, S., Shin, H., & Cerniglia, C. A. (2019). Abbreviated MRI of the foot in patients with suspected osteomyelitis. Emergency radiology, EPub ahead of print. doi:10.1007/s10140-019-01722-y
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  To determine the diagnostic accuracy of an abbreviated magnetic resonance imaging (MRI) protocol of the foot for the diagnosis of osteomyelitis in patients with acute foot infection.
• Li, Z., Bilgin, A., Johnson, K., Galons, J. P., Vedantham, S., Martin, D. R., & Altbach, M. I. (2019). Rapid High-Resolution T1 Mapping Using a Highly Accelerated Radial Steady-state Free-precession Technique. Journal of magnetic resonance imaging : JMRI, 49(1), 239-252. doi:10.1002/jmri.26170
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  T mapping is often used in some clinical protocols. Existing techniques are limited in slice coverage, and/or spatial-temporal resolution, or require long acquisitions. Here we present a multi-slice inversion-recovery (IR) radial steady-state free precession (radSSFP) pulse sequence combined with a principal component (PC) based reconstruction that overcomes these limitations.
• Mushtaq, R., Desoky, S. M., Morello, F., Gilbertson-Dahdal, D., Leetch, A. N., Vedantham, S., Gopalakrishnan, G., Kalb, B. T., Martin, D. R., & Udayasankar, U. (2019). First-Line Diagnostic Evaluation of Children with Suspected Acute Appendicitis using MRI. Radiology, 291(1), 170-177. doi:10.1148/radiol.2019181959
• 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).
• Sujlana, P. S., Mahesh, M., Vedantham, S., Harvey, S. C., Mullen, L. A., & Woods, R. W. (2019). Digital breast tomosynthesis: Image acquisition principles and artifacts. Clinical imaging, 55, 188-195. doi:10.1016/j.clinimag.2018.07.013
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  Digital breast tomosynthesis (DBT) is a new technology that is being used more frequently for both breast cancer screening and diagnostic purposes and its utilization is likely to continue to increase over time. The major benefit of tomosynthesis over 2D-mammography is that it allows radiologists to view breast tissue using a three-dimensional dataset and improves diagnostic accuracy by facilitating differentiation of potentially malignant lesions from overlap of normal tissue. In addition, image processing techniques allow reconstruction of two dimensional synthesized mammograms (SM) from DBT data, which eliminates the need for acquiring two dimensional full field digital mammography (FFDM) in addition to tomosynthesis and thereby reduces the radiation dose. DBT systems incorporate a moveable x-ray tube, which moves in a prescribed way over a limited angular range to obtain three-dimensional data of patients' breasts, and utilize reconstruction algorithms. The limited angular range for DBT leads to incomplete sampling of the object, and a movable x-ray tube prolongs the imaging time, both of which make DBT and SM susceptible to artifacts. Understanding the etiology of these artifacts should help radiologists in reducing the number of artifacts and in differentiating a true finding from one related to an artifact, thus potentially decreasing recall rates and false positive rates. This is becoming especially important with increased incorporation of DBT in practices around the world. The goal of this article is to review the physics principles behind DBT systems and use these principles to explain the origin of artifacts that can limit diagnostic evaluation.
• Tseng, H. W., Vedantham, S., Cho, S. H., & Karellas, A. (2019). Joint optimization of collimator and reconstruction parameters in x-ray fluorescence computed tomography using analytical point spread function and model observer. IEEE transactions on bio-medical engineering.
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  To jointly optimize collimator design and image reconstruction algorithm in X-ray Fluorescence Computed Tomography (XFCT) for imaging low concentrations of high atomic number (Z) elements in small animal models.
• Vijayaraghavan, G. R., Newburg, A., & Vedantham, S. (2019). Positive Predictive Value of Tomosynthesis-guided Biopsies of Architectural Distortions Seen on Digital Breast Tomosynthesis and without an Ultrasound Correlate. Journal of clinical imaging science, 9, 53.
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  The objective of the study was to determine the positive predictive value (PPV) of architectural distortions (AD) observed on digital breast tomosynthesis (DBT) and without an ultrasound (US) correlate.
• Kalb, B. T., Martin, D. R., Vedantham, S., Funk, J., Lin, F. C., Twiss, C. O., & Arif Tiwari, H. (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.
• Marosfoi, M., Clarencon, F., Langan, E. T., King, R. M., Brooks, O. W., Tamura, T., Wainwright, J. M., Gounis, M. J., Vedantham, S., & Puri, A. S. (2018). Acute thrombus formation on phosphorilcholine surface modified flow diverters. Journal of neurointerventional surgery, 10(4), 406-411.
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  Thromboembolic complications remain a limitation of flow diverting stents. We hypothesize that phosphorilcholine surface modified flow diverters (Pipeline Flex with Shield Technology, sPED) would have less acute thrombus formation on the device surface compared with the classic Pipeline Embolization device (cPED).
• O'Connell, A. M., Karellas, A., Vedantham, S., & Kawakyu-O'Connor, D. T. (2018). Newer Technologies in Breast Cancer Imaging: Dedicated Cone-Beam Breast Computed Tomography. Seminars in ultrasound, CT, and MR, 39(1), 106-113.
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  Dedicated breast computed tomography (CT) is the latest in a long history of breast imaging techniques dating back to the 1960s. Breast imaging is performed both for cancer screening as well as for diagnostic evaluation of symptomatic patients. Dedicated breast CT received US Food and Drug Administration approval for diagnostic use in 2015 and is slowly gaining recognition for its value in diagnostic 3-dimensional imaging of the breast, and also for injected contrast-enhanced imaging applications. Conventional mammography has known limitations in sensitivity and specificity, especially in dense breasts. Breast tomosynthesis was US Food and Drug Administration approved in 2011 and is now widely used. Dedicated breast CT is the next technological advance, combining real 3-dimensional imaging with the ease of contrast administration. The lack of painful compression and manipulation of the breasts also makes dedicated breast CT much more acceptable for the patients.
• Shi, L., Vedantham, S., Karellas, A., & Zhu, L. (2018). The role of off-focus radiation in scatter correction for dedicated cone beam breast CT. Medical physics, 45(1), 191-201.
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  Dedicated cone beam breast CT (CBBCT) suffers from x-ray scatter contamination. We aim to identify the source of the significant difference between the scatter distributions estimated by two recent methods proposed by our group and to investigate its effect on CBBCT image quality.
• Vedantham, S., & Karellas, A. (2018). Emerging Breast Imaging Technologies on the Horizon. Seminars in ultrasound, CT, and MR, 39(1), 114-121.
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  Early detection of breast cancers by mammography in conjunction with adjuvant therapy has contributed to reduction in breast cancer mortality. Mammography remains the "gold-standard" for breast cancer screening but is limited by tissue superposition. Digital breast tomosynthesis and more recently, dedicated breast computed tomography have been developed to alleviate the tissue superposition problem. However, all of these modalities rely upon x-ray attenuation contrast to provide anatomical images, and there are ongoing efforts to develop and clinically translate alternative modalities. These emerging modalities could provide for new contrast mechanisms and may potentially improve lesion detection and diagnosis. In this article, several of these emerging modalities are discussed with a focus on technologies that have advanced to the stage of in vivo clinical evaluation.
• Vijayaraghavan, G. R., Vedantham, S., Santos-Nunez, G., & Hultman, R. (2018). Unifocal Invasive Lobular Carcinoma: Tumor Size Concordance Between Preoperative Ultrasound Imaging and Postoperative Pathology. Clinical breast cancer.
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  We systematically analyzed the extent of disease in unifocal invasive lobular carcinoma (ILC) using ultrasonography, with the histopathologic findings as the reference standard.
• Marosfoi, M., Langan, E. T., Strittmatter, L., van, d., Vedantham, S., Arends, J., Lylyk, I. R., Loganathan, S., Hendricks, G. M., Szikora, I., Puri, A. S., Wakhloo, A. K., & Gounis, M. J. (2017). In situ tissue engineering: endothelial growth patterns as a function of flow diverter design. JOURNAL OF NEUROINTERVENTIONAL SURGERY, 9(10), 994-998.
• Shi, L., Vedantham, S., Karellas, A., & Zhu, L. (2017). X-ray scatter correction for dedicated cone beam breast CT using a forward-projection model. MEDICAL PHYSICS, 44(6), 2312-2320.
• Shrestha, S., Vedantham, S., & Karellas, A. (2017). Towards standardization of x-ray beam filters in digital mammography and digital breast tomosynthesis: Monte Carlo simulations and analytical modelling. Physics in medicine and biology, 62(5), 1969-1993.
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  In digital breast tomosynthesis and digital mammography, the x-ray beam filter material and thickness vary between systems. Replacing K-edge filters with Al was investigated with the intent to reduce exposure duration and to simplify system design. Tungsten target x-ray spectra were simulated with K-edge filters (50 µm Rh; 50 µm Ag) and Al filters of varying thickness. Monte Carlo simulations were conducted to quantify the x-ray scatter from various filters alone, scatter-to-primary ratio (SPR) with compressed breasts, and to determine the radiation dose to the breast. These data were used to analytically compute the signal-difference-to-noise ratio (SDNR) at unit (1 mGy) mean glandular dose (MGD) for W/Rh and W/Ag spectra. At SDNR matched between K-edge and Al filtered spectra, the reductions in exposure duration and MGD were quantified for three strategies: (i) fixed Al thickness and matched tube potential in kilovolts (kV); (ii) fixed Al thickness and varying the kV to match the half-value layer (HVL) between Al and K-edge filtered spectra; and, (iii) matched kV and varying the Al thickness to match the HVL between Al and K-edge filtered spectra. Monte Carlo simulations indicate that the SPR with and without the breast were not different between Al and K-edge filters. Modelling for fixed Al thickness (700 µm) and kV matched to K-edge filtered spectra, identical SDNR was achieved with 37-57% reduction in exposure duration and with 2-20% reduction in MGD, depending on breast thickness. Modelling for fixed Al thickness (700 µm) and HVL matched by increasing the kV over (0,4) range, identical SDNR was achieved with 62-65% decrease in exposure duration and with 2-24% reduction in MGD, depending on breast thickness. For kV and HVL matched to K-edge filtered spectra by varying Al filter thickness over (700, 880) µm range, identical SDNR was achieved with 23-56% reduction in exposure duration and 2-20% reduction in MGD, depending on breast thickness. These simulations indicate that increased fluence with Al filter of fixed or variable thickness substantially decreases exposure duration while providing for similar image quality with moderate reduction in MGD.
• Taschner, C. A., Vedantham, S., de, V. J., Biondi, A., Boogaarts, J., Sakai, N., Lylyk, P., Szikora, I., Meckel, S., Urbach, H., Kan, P., Siekmann, R., Bernardy, J., Gounis, M. J., & Wakhloo, A. K. (2017). Surpass Flow Diverter for Treatment of Posterior Circulation Aneurysms. AMERICAN JOURNAL OF NEURORADIOLOGY, 38(3), 582-589.
• Ulano, A. C., Vedantham, S., & Takhtani, D. (2017). Revisiting the indirect signs of a temporal bone fracture: air, air, everywhere. Emergency radiology, 24(5), 497-503.
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  The standard head CT protocol makes detection of a temporal bone fracture difficult. The purposes of our study are to revisit the finding of air in various locations around the temporal bone as an indirect sign of fracture and determine if findings could predict fracture pattern.
• Vijayaraghavan, G. R., Vedantham, S., Kataoka, M., DeBenedectis, C., & Quinlan, R. M. (2017). The Relevance of Ultrasound Imaging of Suspicious Axillary Lymph Nodes and Fine-needle Aspiration Biopsy in the Post-ACOSOG Z11 Era in Early Breast Cancer. ACADEMIC RADIOLOGY, 24(3), 308-315.
• van, d., Vedantham, S., van, d., Howk, M., Narain, T., Ty, K., Karellas, A., Gounis, M. J., Puri, A. S., & Wakhloo, A. K. (2017). Reduced Patient Radiation Exposure during Neurodiagnostic and Interventional X-Ray Angiography with a New Imaging Platform. AMERICAN JOURNAL OF NEURORADIOLOGY, 38(3), 442-449.
• Michaelsen, K. E., Krishnaswamy, V., Shi, L., Vedantham, S., Karellas, A., Pogue, B. W., Paulsen, K. D., & Poplack, S. P. (2016). Effects of breast density and compression on normal breast tissue hemodynamics through breast tomosynthesis guided near-infrared spectral tomography. Journal of biomedical optics, 21(9), 91316.
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  Optically derived tissue properties across a range of breast densities and the effects of breast compression on estimates of hemoglobin, oxygen metabolism, and water and lipid concentrations were obtained from a coregistered imaging system that integrates near-infrared spectral tomography (NIRST) with digital breast tomosynthesis (DBT). Image data were analyzed from 27 women who underwent four IRB approved NIRST/DBT exams that included fully and mildly compressed breast acquisitions in two projections—craniocaudal (CC) and mediolateral-oblique (MLO)—and generated four data sets per patient (full and moderate compression in CC and MLO views). Breast density was correlated with HbT (r=0.64, p=0.001), water (r=0.62, p=0.003), and lipid concentrations (r=?0.74, p
• Shi, L., Vedantham, S., Karellas, A., & Zhu, L. (2016). Library based x-ray scatter correction for dedicated cone beam breast CT. MEDICAL PHYSICS, 43(8), 4529-4544.
• Vedantham, S., Shrestha, S., Karellas, A., Shi, L., Gounis, M. J., Bellazzini, R., Spandre, G., Brez, A., & Minuti, M. (2016). Photon-counting hexagonal pixel array CdTe detector: Spatial resolution characteristics for image-guided interventional applications. MEDICAL PHYSICS, 43(5).
• Chueh, J. Y., Vedantham, S., Wakhloo, A. K., Carniato, S. L., Puri, A. S., Bzura, C., Coffin, S., Bogdanov, A. A., & Gounis, M. J. (2015). Aneurysm permeability following coil embolization: packing density and coil distribution. Journal of neurointerventional surgery, 7(9), 676-81.
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  Rates of durable aneurysm occlusion following coil embolization vary widely, and a better understanding of coil mass mechanics is desired. The goal of this study is to evaluate the impact of packing density and coil uniformity on aneurysm permeability.
• Dundamadappa, S. K., Thangasamy, S., Resteghini, N., Vedantham, S., Chen, A., & Takhtani, D. (2015). Skull fractures in pediatric patients on computerized tomogram: comparison between routing bone window images and 3D volume-rendered images. Emergency radiology, 22(4), 367-72.
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  Skull fracture is a common finding following head trauma. It has a prognostic significance and its presence points to severe trauma. Additionally, there is a greater possibility of detecting associated small underlying extra-axial hematomas and subtle injuries to the brain parenchyma. In pediatric patients, the presence of multiple open sutures often makes fracture evaluation challenging. In our experience, 3D volume (3DV)-rendered CT images complement routine axial bone window (RBW) images in detection and characterization of fractures. This is a multi-reader, multi-case, paired retrospective study to compare the sensitivity and specificity of RBW and 3DV images in detection of calvarial fractures in pediatric patients. A total of 60 cases (22 with fractures and 38 without) were analyzed. Two experienced neuroradiologists and a radiology trainee were the readers of the study. For all readers, the sensitivity was not statistically different between the RBW and the 3DV interpretations. For each reader, there was a statistically significant difference in the interpretation times between the RBW and the 3DV viewing formats. A greater number of sutural diastasis was identified on 3DV. We propose that 3DV images should be part of routine head trauma imaging, especially in the pediatric age group. It requires minimal post-processing time and no additional radiation. Furthermore, 3DV images help in reducing the interpretation time and also enhance the ability of the radiologist to characterize the calvarial fractures.
• Marosfoi, M. G., Korin, N., Gounis, M. J., Uzun, O., Vedantham, S., Langan, E. T., Papa, A. L., Brooks, O. W., Johnson, C., Puri, A. S., Bhatta, D., Kanapathipillai, M., Bronstein, B. R., Chueh, J. Y., Ingber, D. E., & Wakhloo, A. K. (2015). Shear-Activated Nanoparticle Aggregates Combined With Temporary Endovascular Bypass to Treat Large Vessel Occlusion. Stroke, 46(12), 3507-13.
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  The goal of this study is to combine temporary endovascular bypass (TEB) with a novel shear-activated nanotherapeutic (SA-NT) that releases recombinant tissue-type plasminogen activator (r-tPA) when exposed to high levels of hemodynamic stress and to determine if this approach can be used to concentrate r-tPA at occlusion sites based on high shear stresses created by stent placement.
• Michaelsen, K. E., Krishnaswamy, V., Shi, L., Vedantham, S., Poplack, S. P., Karellas, A., Pogue, B. W., & Paulsen, K. D. (2015). Calibration and optimization of 3D digital breast tomosynthesis guided near infrared spectral tomography. Biomedical optics express, 6(12), 4981-91.
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  Calibration of a three-dimensional multimodal digital breast tomosynthesis (DBT) x-ray and non-fiber based near infrared spectral tomography (NIRST) system is challenging but essential for clinical studies. Phantom imaging results yielded linear contrast recovery of total hemoglobin (HbT) concentration for cylindrical inclusions of 15 mm, 10 mm and 7 mm with a 3.5% decrease in the HbT estimate for each 1 cm increase in inclusion depth. A clinical exam of a patient's breast containing both benign and malignant lesions was successfully imaged, with greater HbT was found in the malignancy relative to the benign abnormality and fibroglandular regions (11 μM vs. 9.5 μM). Tools developed improved imaging system characterization and optimization of signal quality, which will ultimately improve patient selection and subsequent clinical trial results.
• Vedantham, S., Karellas, A., Vijayaraghavan, G. R., & Kopans, D. B. (2015). Digital Breast Tomosynthesis: State of the Art. Radiology, 663-684.
• Vedantham, S., Shi, L., Michaelsen, K. E., Krishnaswamy, V., Pogue, B. W., Poplack, S. P., Karellas, A., & Paulsen, K. D. (2015). Digital Breast Tomosynthesis guided Near Infrared Spectroscopy: Volumetric estimates of fibroglandular fraction and breast density from tomosynthesis reconstructions. Biomedical physics & engineering express, 1(4), 045202 (13 pages).
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  A multimodality system combining a clinical prototype digital breast tomosynthesis with its imaging geometry modified to facilitate near-infrared spectroscopic imaging has been developed. The accuracy of parameters recovered from near-infrared spectroscopy is dependent on fibroglandular tissue content. Hence, in this study, volumetric estimates of fibroglandular tissue from tomosynthesis reconstructions were determined. A kernel-based fuzzy c-means algorithm was implemented to segment tomosynthesis reconstructed slices in order to estimate fibroglandular content and to provide anatomic priors for near-infrared spectroscopy. This algorithm was used to determine volumetric breast density (VBD), defined as the ratio of fibroglandular tissue volume to the total breast volume, expressed as percentage, from 62 tomosynthesis reconstructions of 34 study participants. For a subset of study participants who subsequently underwent mammography, VBD from mammography matched for subject, breast laterality and mammographic view was quantified using commercial software and statistically analyzed to determine if it differed from tomosynthesis. Summary statistics of the VBD from all study participants were compared with prior independent studies. The fibroglandular volume from tomosynthesis and mammography were not statistically different (p=0.211, paired t-test). After accounting for the compressed breast thickness, which were different between tomosynthesis and mammography, the VBD from tomosynthesis was correlated with (r =0.809, p0.99, paired t-test), and was linearly related to, the VBD from mammography. Summary statistics of the VBD from tomosynthesis were not statistically different from prior studies using high-resolution dedicated breast computed tomography. The observation of correlation and linear association in VBD between mammography and tomosynthesis suggests that breast density associated risk measures determined for mammography are translatable to tomosynthesis. Accounting for compressed breast thickness is important when it differs between the two modalities. The fibroglandular volume from tomosynthesis reconstructions is similar to mammography indicating suitability for use during near-infrared spectroscopy.
• Vijayaraghavan, G. R., Vedantham, S., Rangan, V., Karam, A., Zheng, L., Roychowdhury, A., & Hussain, S. (2015). Effect of needle gauge and lobe laterality on parenchymal liver biopsy outcome: a retrospective analysis. Abdominal imaging, 40(5), 1223-9.
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  To analyze the effect of lobe selection, needle gauge, and number of passes on procedure outcomes in terms of specimen length and post-procedure complications.
• Gounis, M. J., Vedantham, S., Weaver, J. P., Puri, A. S., Brooks, C. S., Wakhloo, A. K., & Bogdanov Jr., A. A. (2014). Myeloperoxidase in Human Intracranial Aneurysms Preliminary Evidence. STROKE, 45(5), 1474-1477.
• O'Connell, A. M., Karellas, A., & Vedantham, S. (2014). The Potential Role of Dedicated 3D Breast CT as a Diagnostic Tool: Review and Early Clinical Examples. BREAST JOURNAL, 20(6), 592-605.
• Vedantham, S., O'Connell, A. M., Shi, L., Karellas, A., Huston, A. J., & Skinner, K. A. (2014). Dedicated Breast CT: Feasibility for Monitoring Neoadjuvant Chemotherapy Treatment. Journal of clinical imaging science, 4, 64 (9 pages).
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  In this prospective pilot study, the feasibility of non-contrast dedicated breast computed tomography (bCT) to determine primary tumor volume and monitor its changes during neoadjuvant chemotherapy (NAC) treatment was investigated.
• Vedantham, S., Shi, L., & Karellas, A. (2014). Large-angle x-ray scatter in Talbot-Lau interferometry for breast imaging. Physics in medicine and biology, 59(21), 6387-400.
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  Monte Carlo simulations were used to investigate large-angle x-ray scatter at design energy of 25 keV during small field of view (9.6 cm × 5 cm) differential phase contrast imaging of the breast using Talbot-Lau interferometry. Homogenous, adipose and fibroglandular breasts of uniform thickness ranging from 2 to 8 cm encompassing the field of view were modeled. Theoretically determined transmission efficiencies of the gratings were used to validate the Monte Carlo simulations, followed by simulations to determine the x-ray scatter reaching the detector. The recorded x-ray scatter was classified into x-ray photons that underwent at least one Compton interaction (incoherent scatter) and Rayleigh interaction alone (coherent scatter) for further analysis. Monte Carlo based estimates of transmission efficiencies showed good correspondence [Formula: see text] with theoretical estimates. Scatter-to-primary ratio increased with increasing breast thickness, ranging from 0.11 to 0.22 for 2-8 cm thick adipose breasts and from 0.12 to 0.28 for 2-8 cm thick fibroglandular breasts. The analyzer grating reduced incoherent scatter by ~18% for 2 cm thick adipose breast and by ~35% for 8 cm thick fibroglandular breast. Coherent scatter was the dominant contributor to the total scatter. Coherent-to-incoherent scatter ratio ranged from 2.2 to 3.1 for 2-8 cm thick adipose breasts and from 2.7 to 3.4 for 2-8 cm thick fibroglandular breasts.
• Shi, L., Vedantham, S., Karellas, A., & O'Connell, A. M. (2013). Technical Note: Skin thickness measurements using high-resolution flat-panel cone-beam dedicated breast CT. MEDICAL PHYSICS, 40(3).
• Vedantham, S., & Karellas, A. (2013). X-ray phase contrast imaging of the breast: Analysis of tissue simulating materials. MEDICAL PHYSICS, 40(4).
• Vedantham, S., Karellas, A., Emmons, M. M., Moss, L. J., Hussain, S., & Baker, S. P. (2013). Dedicated breast CT: geometric design considerations to maximize posterior breast coverage. Physics in medicine and biology, 58(12), 4099-118.
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  An Institutional Review Board-approved protocol was used to quantify breast tissue inclusion in 52 women, under conditions simulating both craniocaudal (CC) and mediolateral oblique (MLO) views in mammography, dedicated breast CT in the upright subject position, and dedicated breast CT in the prone subject position. Using skin as a surrogate for the underlying breast tissue, the posterior aspect of the breast that is aligned with the chest-wall edge of the breast support in a screen-film mammography system was marked with the study participants positioned for CC and MLO views. The union of skin marks with the study participants positioned for CC and MLO views was considered to represent chest-wall tissue available for imaging with mammography and served as the reference standard. For breast CT, a prone stereotactic breast biopsy unit and a custom-fabricated barrier were used to simulate conditions during prone and upright breast CT, respectively. For the same breast marked on the mammography system, skin marks were made along the breast periphery that was just anterior to the apertures of the prone biopsy unit and the upright barrier. The differences in skin marks between subject positioning simulating breast CT (prone, upright) and mammography were quantified at six anatomic locations. For each location, at least one study participant had a skin mark from breast CT (prone, upright) posterior to mammography. However for all study participants, there was at least one anatomic location where the skin mark from mammography was posterior to that from breast CT (prone, upright) positioning. The maximum amount by which the skin mark from mammography was posterior to breast CT (prone and upright) over all six locations was quantified for each study participant and pair-wise comparison did not exhibit statistically significant difference between prone and upright breast CT (paired t- test, p = 0.4). Quantitatively, for 95% of the study participants the skin mark from mammography was posterior to breast CT (prone or upright) by at the most 9 mm over all six locations. Based on the study observations, geometric design considerations targeting chest-wall coverage with breast CT equivalent to mammography, wherein part of the x-ray beam images through the swale during breast CT are provided. Assuming subjects can extend their chest in to a swale, the optimal swale-depth required to achieve equivalent coverage with breast CT images as mammograms for 95% of the subjects varies in the range of ~30-50 mm for clinical prototypes and was dependent on the system geometry.
• Vedantham, S., Shi, L., Glick, S. J., & Karellas, A. (2013). Scaling-law for the energy dependence of anatomic power spectrum in dedicated breast CT. MEDICAL PHYSICS, 40(1).
• Vedantham, S., Shi, L., Karellas, A., O'Connell, A. M., & Conover, D. L. (2013). Personalized estimates of radiation dose from dedicated breast CT in a diagnostic population and comparison with diagnostic mammography. PHYSICS IN MEDICINE AND BIOLOGY, 58(22), 7921-7936.
• van, d., Hou, S. Y., Puri, A. S., Spilberg, G., Ruijters, D., van, d., Carelsen, B., Vedantham, S., Gounis, M. J., & Wakhloo, A. K. (2013). Reduction of Coil Mass Artifacts in High-Resolution Flat Detector Conebeam CT of Cerebral Stent-Assisted Coiling. AMERICAN JOURNAL OF NEURORADIOLOGY, 34(11), 2163-2170.
• Vedantham, S., Shi, L., Karellas, A., & Noo, F. (2012). Dedicated breast CT: radiation dose for circle-plus-line trajectory. MEDICAL PHYSICS, 39(3), 1530-1541.
• Vedantham, S., Shi, L., Karellas, A., & O'Connell, A. M. (2012). Dedicated breast CT: Fibroglandular volume measurements in a diagnostic population. MEDICAL PHYSICS, 39(12), 7317-7328.
• Vedantham, S., & Karellas, A. (2010). Modeling the Performance Characteristics of Computed Radiography (CR) Systems. IEEE TRANSACTIONS ON MEDICAL IMAGING, 29(3), 790-806.
• Karellas, A., & Vedantham, S. (2008). Breast cancer imaging: a perspective for the next decade. Medical physics, 35(11), 4878-97.
  More info

  Breast imaging is largely indicated for detection, diagnosis, and clinical management of breast cancer and for evaluation of the integrity of breast implants. In this work, a prospective view of techniques for breast cancer detection and diagnosis is provided based on an assessment of current trends. The potential role of emerging techniques that are under various stages of research and development is also addressed. It appears that the primary imaging tool for breast cancer screening in the next decade will be high-resolution, high-contrast, anatomical x-ray imaging with or without depth information. MRI and ultrasonography will have an increasingly important adjunctive role for imaging high-risk patients and women with dense breasts. Pilot studies with dedicated breast CT have demonstrated high-resolution three-dimensional imaging capabilities, but several technological barriers must be overcome before clinical adoption. Radionuclide based imaging techniques and x-ray imaging with intravenously injected contrast offer substantial potential as a diagnostic tools and for evaluation of suspicious lesions. Developing optical and electromagnetic imaging techniques hold significant potential for physiologic information and they are likely to be of most value when integrated with or adjunctively used with techniques that provide anatomic information. Experimental studies with breast specimens suggest that phase-sensitive x-ray imaging techniques can provide edge enhancement and contrast improvement but more research is needed to evaluate their potential role in clinical breast imaging. From the technological perspective, in addition to improvements within each modality, there is likely to be a trend towards multi-modality systems that combine anatomic with physiologic information. We are also likely to transition from a standardized screening, where all women undergo the same imaging exam (mammography), to selection of a screening modality or modalities based an individual-risk or other classification.
• Sechopoulos, I., Suryanarayanan, S., Vedantham, S., D'Orsi, C. J., & Karellas, A. (2008). Radiation dose to organs and tissues from mammography: Monte Carlo and phantom study. RADIOLOGY, 246(2), 434-443.
• Sechopoulos, I., Vedantham, S., Suryanarayanan, S., D'Orsi, C. J., & Karellas, A. (2008). Monte Carlo and phantom study of the radiation dose to the body from dedicated CT of the breast. RADIOLOGY, 247(1), 98-105.
• Sechopoulos, I., Suryanarayanan, S., Vedantham, S., D'Orsi, C. J., & Karellas, A. (2007). Scatter radiation in digital tomosynthesis of the breast. MEDICAL PHYSICS, 34(2), 564-576.
• Sechopoulos, I., Suryanarayanan, S., Vedantham, S., D'Orsi, C., & Karellas, A. (2007). Computation of the glandular radiation dose in digital tomosynthesis of the breast. MEDICAL PHYSICS, 34(1), 221-232.
• Suryanarayanan, S., Karellas, A., Vedantham, S., Sechopoulos, I., & D'Orsi, C. J. (2007). Detection of simulated microcalcifications in a phantom with digital mammography: Effect of pixel size. RADIOLOGY, 244(1), 130-137.
• Suryanarayanan, S., Karellas, A., Vedantham, S., & Sechopoulos, I. (2006). Theoretical analysis of high-resolution digital mammography. PHYSICS IN MEDICINE AND BIOLOGY, 51(12), 3041-3055.
• Suryanarayanan, S., Karellas, A., Vedantham, S., & Onishi, S. K. (2005). High-resolution imager for digital mammography: physical characterization of a prototype sensor. Physics in medicine and biology, 50(17), 3957-69.
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  The physical performance characteristics of a high-resolution sensor module for digital mammography were investigated. The signal response of the imager was measured at various detector entrance air kerma and was found to be linear. The spatial resolution was determined by measuring the presampling modulation transfer function, MTF(f), of the system. The noise power spectra, NPS(f), of the system were estimated using 26 kVp: Mo/Mo, 28 kVp: Mo/Rh and 30 kVp: Rh/Rh, with polymethyl methacrylate (PMMA) 'tissue equivalent material' of thickness 20, 45 and 57 mm for each of three x-ray spectra at detector entrance air kerma in the range between approximately 80.2 and 92.3 microGy. The noise equivalent quanta, NEQ(f), and detective quantum efficiencies, DQE(f), for the various spectral conditions were computed. In addition, dose dependence of NPS(f) and DQE(f) was studied at various detector entrance air kerma ranging from 9.4 to 169.7 microGy. A spatial resolution of about 10 cycles mm(-1) was obtained at the 10% MTF(f) level. A small increase in NEQ(f)was observed under higher energy spectral conditions while the DQE(f) decreased marginally. For a given spectrum, increasing PMMA filtration produced negligible change in DQE(f). The estimated DQE values at zero frequency were in the range between 0.45 and 0.55 under the conditions investigated in this study.
• Suryanarayanan, S., Karellas, A., Vedantham, S., Waldrop, S. M., & D'Orsi, C. (2005). Detection of simulated lesions on data-compressed digital mammograms. RADIOLOGY, 236(1), 31-36.
• Suryanarayanan, S., Karellas, A., & Vedantham, S. (2004). Physical characteristics of a full-field digital mammography system. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 533(3), 560-570.
• Suryanarayanan, S., Karellas, A., Vedantham, S., Waldrop, S. M., & D'Orsi, C. (2004). A perceptual evaluation of JPEG 2000 image compression for digital mammography: Contrast-detail characteristics. JOURNAL OF DIGITAL IMAGING, 17(1), 64-70.
• Vedantham, S., Karellas, A., & Suryanarayanan, S. (2004). Solid-state fluoroscopic imager for high-resolution angiography: Parallel-cascaded linear systems analysis. MEDICAL PHYSICS, 31(5), 1258-1268.
• Vedantham, S., Karellas, A., Suryanarayanan, S., & Onishi, S. K. (2004). Solid-state fluoroscopic imager for high-resolution angiography: Physical characteristics of an 8cmX8cm experimental prototype. MEDICAL PHYSICS, 31(6), 1462-1472.
• Vedantham, S., Karellas, A., & Suryanarayanan, S. (2003). Attenuation characteristics of fiberoptic plates for digital mammography and other X-ray imaging applications. Journal of X-ray science and technology, 11(4), 219-30.
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  Spatially coherent fiberoptic plates are important components of some charge-coupled device (CCD)-based x-ray imaging systems. These plates efficiently transmit scintillations from the phosphor, and also filter out x-rays not absorbed by the phosphor, thus protecting the CCD from direct x-ray interaction. The thickness of the fiberoptic plate and the CCD package present a significant challenge in the design of a digital x-ray cassette capable of insertion into the existing film-screen cassette holders of digital mammography systems. This study was performed with an aim to optimize fiberoptic plate thickness. Attenuation measurements were performed on nine fiberoptic plates varying in material composition that exhibit desirable optical characteristics such as good coupling efficiency. Mammographic spectra from a clinical mammographic system and an Americium-241 (Am-241) source (59.54 KeV) were used. The spectra were recorded with a high-resolution cadmium zinc telluride (CZT)-based spectrometer and corrected for dead time and pile-up. The linear attenuation coefficients varied by a factor of 3 in the set of tested fiberoptic plates at both mammographic energies and 59.54 keV. Our results suggest that a 3-mm thick high-absorption plate might provide adequate for shielding at mammographic energies. A thickness of 2-mm is feasible for mammographic applications with further optimization of the fiberoptic plate composition by incorporating non-scintillating, high-atomic number material. This would allow more space for cooling components of the cassette and for a more compact device, which is critical for clinical implementation of the technology.
• Suryanarayanan, S., Karellas, A., Vedantham, S., Ved, H., Baker, S. P., & D'Orsi, C. (2002). Flat-panel digital mammography system: Contrast-detail comparison between screen-film radiographs and hard-copy images. RADIOLOGY, 225(3), 801-807.
• Suryanarayanan, S., Karellas, A., Vedantham, S., Baker, S. P., Glick, S. J., D'Orsi, C., & Webber, R. L. (2001). Evaluation of linear and nonlinear tomosynthetic reconstruction methods in digital mammography. ACADEMIC RADIOLOGY, 8(3), 219-224.
• Suryanarayanan, S., Karellas, A., Vedantham, S., Glick, S. J., D'Orsi, C., Baker, S. P., & Webber, R. L. (2000). Comparison of tomosynthesis methods used with digital mammography. ACADEMIC RADIOLOGY, 7(12), 1085-1097.
• Vedantham, S., Karellas, A., Suryanarayanan, S., Albagli, D., Han, S., Tkaczyk, E. J., Landberg, C. E., Opsahl-Ong, B., Granfors, P. R., Levis, I., D'Orsi, C., & Hendrick, R. E. (2000). Full breast digital mammography with an amorphous silicon-based flat panel detector: Physical characteristics of a clinical prototype. MEDICAL PHYSICS, 27(3), 558-567.
• Vedantham, S., Karellas, A., Suryanarayanan, S., D'Orsi, C., & Hendrick, R. E. (2000). Breast imaging using an amorphous silicon-based full-field digital mammographic system: Stability of a clinical prototype. JOURNAL OF DIGITAL IMAGING, 13(4), 191-199.
• Vedantham, S., Karellas, A., Suryanarayanan, S., Levis, I., Sayag, M., Kleehammer, R., Heidsieck, R., & D'Orsi, C. (2000). Mammographic imaging with a small format CCD-based digital cassette: Physical characteristics of a clinical system. MEDICAL PHYSICS, 27(8), 1832-1840.
• Suryanarayanan, S., Karellas, A., Vedantham, S., Glick, S. J., D'Orsi, C., & Webber, R. L. (1999). Comparison of contrast-detail characteristics of tomosynthetic reconstruction techniques for digital mammography. RADIOLOGY, 213P, 368-369.
• Giakos, G. C., Dasgupta, A., Suryanarayanan, S., Chowdhury, S., Guntupalli, R. K., Vedantham, S., Pillai, B., Passalaqua, A., & Kollipara, S. (1998). Sensitometric response of Cd1-xZnxTe detectors for chest radiography. IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, 47(1), 252-255.
• Giakos, G. C., Vedantham, S., Chowdhury, S., Odogba, J., Dasgupta, A., Pillai, B., Sheffer, D. B., Nemer, R. E., Guntupalli, R. K., Suryanarayanan, S., Vega-Lozada, V., Endorf, R. J., & Passalaqua, A. (1998). Study of detection efficiency of Cd(1-x)Zn(x)Te detectors for digital radiography. IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, 47(1), 244-251.
• Giakos, G. C., Pillai, B., Chowdhury, S., Vedantham, S., Dasgupta, A., Kollipara, S., Passalaqua, A., & Endorf, R. J. (1997). Cd1-xZnx Te Detectors for Digital X-Ray Chest Imaging. Journal of X-ray science and technology, 7(3), 305-15.
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  Radiographic studies with the aim of optimizing the imaging potential of Cd1-xZnxTe detectors for digital chest radiography have been performed. A geometrical chest phantom has been designed, and the dependence of both the signal-to-noise ratio and contrast resolution of a planar Cd1-xZnxTe detector on the phantom thickness has been experimentally determined. Specifically, the detected signal and noise contributions were measured and related to phantom thickness. The results of this study indicate that Cd1-xZnxTe detectors exhibit both high signal-to-noise ratio and contrast resolution. At present time, several studies are in process to experimentally identify and quantify the imaging potential of Cd1-xZnxTe detectors for digital radiographic applications.
• Giakos, G. C., Pillai, B., Chowdhury, S., Vedantham, S., Dasgupta, A., Sheffer, D. B., Davros, W. J., Passalaqua, A., & Endorf, R. J. (1997). Contrast Study of CdZnTe Detectors for Digital Mammography. Journal of X-ray science and technology, 7(3), 317-26.
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  Experiments have been performed with the aim of optimizing the image quality parameters of CdZnTe detectors for digital mammography. A geometrical breast phantom has been designed, and the dependence of the contrast resolution of a planar CdZnTe detector on the phantom thickness has been experimentally determined. Specifically, the detected signal and noise contributions were measured and related to phantom thickness. The results of this study indicate that the CdZnTe detectors exhibit a high contrast resolution. On the other hand, the dynamic range of this detector can be improved significantly by further implementation of the data acquisition electronics.
• Giakos, G. C., Pillai, B., Vedantham, S., Chowdhuri, S., Dasgupta, A., Richardson, R. B., Ghotra, P., Endorf, R. J., Passalaqua, A., & Davros, W. J. (1997). Optimization of Cd1-xZnxTe Detectors for Digital Radiography. Journal of X-ray science and technology, 7(1), 37-49.
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  In this study, measurements of the electrical and detection parameters of the Cd1-xZnxTe detectors, within the x-ray diagnostic energy range, have been performed with the aim of optimizing the image quality parameters of these solid-state-ionization detectors. Namely, the leakage current and system capacitance of the x-ray imaging system have been measured as they relate to signal parameters. Similarly, the detected signal and noise contributions were measured and related to the radiation exposure and tube current setting. Furthermore, the detector contrast has been experimentally determined. The experimental results indicate that Cd1-xZnxTe detectors have low leakage current, high resistivity, and high detector contrast resolution. Therefore, they appear to be very attractive for imaging applications with applications in x-ray digital radiography.
• Giakos, G. C., Pillai, B., Vedantham, S., Chowdhuri, S., Odogba, J., Dasgupta, A., Vega-Lozada, V., Guntupalli, R., Suryanarayanan, S., Endorf, R. J., Passalaqua, A., & Kollipara, S. (1997). Electric Field Dependence on Charge Collection of CdZnTe X-Ray Detectors. Journal of X-ray science and technology, 7(2), 198-210.
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  In this study, the electric field dependence on the charge collection process of CdZnTe detectors, at different x-ray tube settings, within the x-ray diagnostic energy range, is investigated. In addition, the detector contrast at different applied bias voltages and x-ray tube settings have been experimentally determined. The experimental results suggest that an efficient charge collection process is obtained by increasing the applied bias voltage. Once the applied bias voltage is sufficiently high, charge collection becomes complete and the detector operates in the saturation region. This is a prerequisite for high contrast and spatial resolution. As a result, the detector contrast is enhanced significantly. Therefore, CdZnTe detectors appear to be potential candidates for digital radiographic applications.
• Giakos, G. C., Vedantham, S., Pillai, B., Chowdhury, S., Sheffer, D. B., Dasgupta, A., Endorf, R. J., Passalaqua, A., & Kollipara, S. (1997). Signal Dependence on Irradiation Geometry of Cd1-xZnxTe Detectors for Digital X-Ray Imaging. Journal of X-ray science and technology, 7(3), 295-304.
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  CdZnTe is one of the most promising semiconductor material in the field of digital X-ray imaging, and may be operated at room temperature. To improve the detector characteristics, ternary systems such as Cd1-xZnxTe were grown by the high pressure Bridgman (HPG) technique. The signal performance characteristics of quasi-resistive Cd1-xZnxTe semiconductor detectors, was studied at different directions of irradiation, within the X-ray diagnostic energy range. The experimental results suggest that the total efficiency of these semiconductor detectors depends upon the energy absorption efficiency as well as the charge collection efficiency. This imaging detector allows one to investigate methods to improve the detection and imaging performance parameters as part of the development of an X-ray imaging system.
• Giakos, G. C., Ghotra, P., Pillai, B., Chowdhury, S., Vedantham, S., Dibianca, F. A., Jordan, L. M., Devidas, S., Nagarajan, S., & Endorf, R. J. (1996). Line spread function study of kinestatic charge detectors operating at high gas pressures. Journal of X-ray science and technology, 6(4), 343-58.
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  A systematic study of the line spread function (LSF) in the drift direction of a high-pressure ionization chamber for x-ray detection and imaging is presented. Experimental results, obtained by operating a KCD krypton-filled detector at pressures up to 60 atm and constant electric field-to-gas pressure ratio, indicate that the width of the LSF increases with the drift distance and decreases with increasing pressure, both effects being quite large. The hypothesis of this paper is that, at sufficiently high pressures, formation of clusters of molecular ions with a unique or narrowed mobility distribution take place by means of energy exchange mechanisms. Therefore, the LSF of the ionic signal becomes narrower and the FWHM of the ionic signal improves significantly with increasing gas pressure. This research is aimed at investigating methods to improve the spatial resolution as part of the development of a large field-of-view prototype digital radiographic scanner operating on kinestatic charge detection principles.

Proceedings Publications

• Vedantham, S., & Karellas, A. (2017, July). Dedicated breast CT: Numerical evaluation of improvement in x-ray fluence uniformity using 3D beam-shaping x-ray filter.. In 59th Annual Meeting of the AAPM, Medical Physics 44-6, 2017 AAPM Annual Meeting Program, 3177.
• Vedantham, S., & Karellas, A. (2017, Sep). Scintillator performance considerations for dedicated breast computed tomography. In Radiation Detectors in Medicine, Industry, and National Security XVIII, SPIE, Proc. SPIE 10393, 103930M (7 pages).
• Vedantham, S., Shrestha, S., Karellas, A., & Cho, S. H. (2017, Sep). A framework for optimizing micro-CT in dual-modality micro-CT/XFCT small-animal imaging system. In Radiation Detectors in Medicine, Industry, and National Security XVIII, SPIE, Proc. SPIE 10393, 103930R.
• Marosfoi, M., Langan, E., Vedantham, S., Clarencon, F., King, R., Wainwright, J., Gounis, M. J., & Puri, A. (2016, July). Acute thrombus formation on flow diverters imaged in vivo using optical coherence tomography. In 13th Annual Meeting SNIS, J NeuroIntervent Surg 8: Suppl 1, A19-A20.
• Marya, N. B., Shrestha, S., Vedantham, S., Patel, K., Rupawala, A. H., Aldrugh, S., Karam, A. R., Zacharias, I., & Karellas, A. (2016, APR). Radiomics of Computed Tomography (CT) Liver Scans: A Novel Method to Evaluate Liver Cirrhosis and Steatosis. In GASTROENTEROLOGY, 150, S1166-S1167.
• Shi, L., Vedantham, S., Karellas, A., & Zhu, L. (2016, February). Library-based scatter correction for dedicated cone beam breast CT: a feasibility study. In MEDICAL IMAGING 2016: PHYSICS OF MEDICAL IMAGING, 9783.
• Shi, L., Vedantham, S., Karellas, A., & Zhu, L. (2016, JUN). Library-Based X-Ray Scatter Correction for Dedicated Cone-Beam Breast CT: Clinical Validation. In MEDICAL PHYSICS, 43.
• Shi, L., Vedantham, S., Karellas, A., & Zhu, L. (2016, JUN). Scatter Correction for Dedicated Cone Beam Breast CT Based On a Forward Projection Model. In MEDICAL PHYSICS, 43, 3820-+.
• Shrestha, S., Vedantham, S., & Karellas, A. (2016, JUN). Alternative K-Edge Filters for Low-Energy Image Acquisition in Contrast Enhanced Spectral Mammography. In MEDICAL PHYSICS, 43, 3716-+.
• Shrestha, S., Vedantham, S., & Karellas, A. (2016, JUN). Towards Standardization of X-Ray Filters in Digital Mammography-Enabled Breast Tomosynthesis Systems. In MEDICAL PHYSICS, 43.
• Vedantham, S., Shrestha, S., Shi, L., Vijayaraghavan, G., & Karellas, A. (2016, JUN). Task-Specific Optimization of Scintillator Thickness for CMOS-Detector Based Cone-Beam Breast CT. In MEDICAL PHYSICS, 43, 3346-3346.
• Shi, L., Vedantham, S., & Karellas, A. (2015, JUN). Dedicated Cone-Beam Breast CT with Laterally-Shifted Detector: Monte Carlo Evaluation of X-Ray Scatter Distribution and Scatter-To-Primary Ratio. In MEDICAL PHYSICS, 42, 3682-3682.
• Shrestha, S., Vedantham, S., Karellas, A., Bellazzini, R., Spandre, G., & Brez, A. (2015, JUN). Photon-Counting Hexagonal Pixel Array CdTe Detector: Optimal Resampling to Square Pixels. In MEDICAL PHYSICS, 42, 3694-3694.
• Vedantham, S., Shi, L., & Karellas, A. (2015, JUN). Dedicated Cone-Beam Breast CT: Design of a 3-D Beam-Shaping Filter. In MEDICAL PHYSICS, 42, 3612-3612.
• Vedantham, S., Shi, L., Karellas, A., & O'Connell, A. (2015, JUN). Accuracy of Radiologists Interpretation of Mammographic Breast Density. In MEDICAL PHYSICS, 42, 3574-3575.
• Vedantham, S., Shi, L., Karellas, A., Michaelsen, K. E., Krishnaswamy, V., Pogue, B. W., & Paulsen, K. D. (2011, AUG). Semi-automated Segmentation and Classification of Digital Breast Tomosynthesis Reconstructed Images. In 2011 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC), 6188-6191.
• Nagarkar, V. V., Tipnis, S. V., Gaysinskiy, V. B., Miller SR, ., Karellas, A., & Vedantham, S. (2003, FEB). New design of a structured CsI(Tl) screen for digital mammography. In MEDICAL IMAGING 2003: PHYSICS OF MEDICAL IMAGING, PTS 1 AND 2, 5030, 541-546.
• Glick, S. J., Vedantham, S., & Karellas, A. (2002, FEB). Investigation of optimal kVp settings for CT mammography using a flat-panel imager. In MEDICAL IMAGING 2002: PHYSICS OF MEDICAL IMAGING, 4682, 392-402.
• Giakos, G. C., Chowdhury, S., Vedantham, S., Dasgupta, A., Pillai, B., Ghotra, P., Suryanarayanan, S., & Odogba, J. (1997, FEB). Feasibility study of a gas microstrip detector for medical applications. In PHYSICS OF MEDICAL IMAGING - MEDICAL IMAGING 1997, 3032, 459-468.
• Giakos, G. C., Vedantham, S., Chowdhury, S., & Pillai, B. (1997, FEB). Novel hybrid imaging modalities. In PHYSICS OF MEDICAL IMAGING - MEDICAL IMAGING 1997, 3032, 476-487.
• Giakos, G. C., Chowdhury, S., Pillai, B., Ghotra, P., Vedantham, S., & Dasgupta, A. (1996, FEB). Novel multimedia detectors for medical imaging. In PHYSICS OF MEDICAL IMAGING, 2708, 759-770.

Presentations

• 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.
• Fu, Z., Tseng, H., Vedantham, S., Karellas, A., & Bilgin, A. (2019, Dec/Fall). Deep Learning-Driven Sparse-View Reconstruction for Radiation Dose Reduction in Dedicated Breast CT: Quantitative Evaluation.. 105th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA), 2019 RSNA Annual Meeting Program, Abstract # SSC13-05.. Chicago, IL: Radiological Society of North America (RSNA).
• Spicer, C., Kalb, B. T., Martin, D. R., Vedantham, S., & 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).
• Tseng, H., Vedantham, S., & Karellas, A. (2019, February). Radiation dose reduction in dedicated breast computed tomography.. 2019 University of Arizona College of Medicine Research Day. Tucson, AZ: University of Arizona, College of Medicine.
• Tseng, H., Vedantham, S., & Karellas, A. (2019, February). System design in X-ray Fluorescence Computed Tomography (XFCT) using analytical point spread function system matrix.. 2019 University of Arizona College of Medicine Research Day. Tucson, AZ: University of Arizona, College of Medicine.
• Tseng, H., Vedantham, S., Cho, S., & Karellas, A. (2019, Aug 2019). Expedient System Optimization of X-Ray Fluorescence Computed Tomography (XFCT) Using Analytical Point Spread Function and Model Observer. 61st Annual Meeting of the American Association of Physicists in Medicine (AAPM), MEDICAL PHYSICS 46 (6), E191-E191. San Antonio, TX: American Association of Physicists in Medicine (AAPM).
• Vedantham, S. (2019, April/Spring). Quantitative Whole-breast X-ray Imaging. Cancer Prevention & Control (CPC)/Cancer Imaging Program (CIP) Joint Retreat, University of Arizona Cancer Center. Tucson, AZ: University of Arizona Cancer Center.
• Vedantham, S. (2019, Sep 16). Beyond Tomosynthesis: Advancing Fully 3D, Quantitative, Breast Cancer X-ray Imaging. BME Seminar Series. Tucson, AZ: Department of Biomedical Engineering, University of Arizona.
• Vedantham, S. (2019, Sep 2019). Quantitative measurement of breast density. Cancer Prevention and Control Seminar, University of Arizona Cancer Center. Tucson, AZ: University of Arizona Cancer Center.
• Vedantham, S., & Karellas, A. (2019, February). Automated notification: Radiomics of non-contrast CT scans.. 2019 University of Arizona College of Medicine Research Day. Tucson, AZ: University of Arizona College of Medicine.
• Vedantham, S., & Karellas, A. (2019, February). Interventional Radiology: Dual-energy dynamic imaging.. 2019 University of Arizona College of Medicine Research Day. Tucson, AZ: University of Arizona, College of Medicine.
• Arif, H., Kalb, B., Funk, J., Cress, A., Vedantham, S., & Martin, D. R. (2018, March). Magnetic Resonance-directed Ultrasound-guided (MRdUSg) prostate biopsies using a new real-time registration and image display system to improve tumor-targeting accuracy. Annual Scientific Meeting and Educational Course, Society of Abdominal Radiology, 2018. Scottsdale, Arizona: Society of Abdominal Radiology.
• Bhowra, A., Petkovska, I., Martin, D. R., Kalb, B. T., & Vedantham, S. (2018, JUN). The Diagnostic Accuracy of MR Imaging for Acute Pyelonephritis. Joint Annual Meeting ISMRM-ESMRMB 2018. Paris, France: ISMRM.
• Desoky, S. M., Arteaga, V., Vedantham, S., & Taljanovic, M. S. (2018, May). Comparison of Assessment of Medical Student Knowledge Following a Radiology Rotation by Radiology ExamWeb and Institutionally-created Final Examinations: Are the Exams Comparable and Does a Subspecialty Rotation Make a Difference in Performance?. 66th Annual Meeting of the Association of University Radiologists (AUR). Orlando, FL: Association of University Radiologists (AUR).
• Tseng, H., Vedantham, S., & Karellas, A. (2018, Summer). Dedicated Breast CT: Impact of Short-Scan Source Trajectory and Sparse-View Acquisition on Image Quality. 60th Annual Meeting of the American Association of Physicists in Medicine (AAPM), Medical Physics 45 (6), E479-E480. Nashville, TN: AAPM.
• Tseng, H., Vedantham, S., & Karellas, A. (2018, Summer). Impact of GPU-Accelerated Sparse-View Reconstruction for Radiation Dose Reduction in Dedicated Breast CT. 60th Annual Meeting of the American Association of Physicists in Medicine (AAPM), Medical Physics 45 (6), E555-E555. Nashville, TN: AAPM.
• Vedantham, S. (2018, July). Let There Be Light! Photon Counting Detectors as the Next Step. 15th Annual Meeting of the Society of NeuroInterventional Surgery (SNIS 2018). San Francisco, CA: SNIS.
• Vedantham, S. (2018, March). Advances in 3D X-ray Breast Imaging. Cancer Imaging Program Meeting. University of Arizona Cancer Center.
• Litchman, J., Chueh, J. Y., Arslanian, R., Vedantham, S., Carniato, S., Rex, D. E., Howk, M., Gounis, M. J., & Puri, A. S. (2017, Spring). Clot characterization in acute ischemic stroke.. 2017 UMass Center for Clinical and Translational Science Research Retreat. Worcester, MA: UMass Medical School.
• Santos-Nunez, G. A., Kipervasser, E., Vedantham, S., Dundamadappa, S. K., & Takhtani, D. (2017, Dec). Presence of temporal lobe lesions help differentiate multiple sclerosis from small vessel ischemic changes.. 103rd Scientific Assembly and Annual Meeting of the Radiological Society of North America, 2017 RSNA Annual Meeting Program. Chicago, IL: Radiological Society of North America (RSNA).
• Vedantham, S. (2017, Apr). Towards breast cancer screening with dedicated breast computed tomography.. Arizona Research Institute for Biomedical Imaging Spring Workshop. Tucson, AZ: University of Arizona.
• Vedantham, S. (2017, Dec). X-ray imaging of the breast in 3D. 103rd Scientific Assembly and Annual Meeting of the Radiological Society of North America, 2017 RSNA Annual Meeting Program. Chicago, IL: Radiological Society of North America (RSNA).
• Vedantham, S. (2017, Oct). BIG-CT: Overview of research opportunities.. Medical Imaging Grand Rounds, University of Arizona. Tucson, AZ.
• Vedantham, S. (2016, JUN). Introduction to Dedicated Breast CT - Early Studies. MEDICAL PHYSICS.
• Karellas, A., Molloi, S., Zhou, O., Zhao, W., & Vedantham, S. (2015, JUN). Advances in Breast Imaging. MEDICAL PHYSICS.

Poster Presentations

• Tseng, H., Vedantham, S., & Karellas, A. (2019, Aug 2019). Impact of Uniform and Nonuniform Angular Sampling in Short-Scan Dedicated Breast Computed Tomography. 61st Annual Meeting of the American Association of Physicists in Medicine (AAPM), MEDICAL PHYSICS 46 (6), E428-E428. San Antonio, TX: American Association of Physicists in Medicine (AAPM).