Hasan T Ozgur

Interests

Teaching

Brain Imaging, Carotid Imaging, Temporal bone imaging, pain management

Research

Imaging of Invasive fungal sinusitis

Courses

No activities entered.

Scholarly Contributions

Chapters

• Bellon, R., & Özgür, H. T. (2000). Interventional Neuroradiology. In Neuroimaging. doi:10.1007/978-1-4612-1152-5_24

Journals/Publications

• Vilardo, M., Scarramal, J. P., Cardoso, L. J., Günkan, A., Elek, A., Ribeiro Gonçalves, O., Alexandre, A. M., Guenego, A., Dmytriw, A. A., Hanel, R. A., Ozgur, H. T., Kalsoum, E., Pereira, V. M., Clarençon, F., & Scarcia, L. (2026). Silk Vista Baby for intracranial aneurysms: systematic review and proportional meta-analysis. Journal of NeuroInterventional Surgery. doi:10.1136/jnis-2025-024641
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  Background The Silk Vista Baby (SVB) is a low profile flow diverter increasingly used to treat intracranial aneurysms (IAs), especially those in small caliber distal vessels. However, the available evidence remains limited and heterogeneous in terms of design, patient selection, use of adjunctive coiling, and follow-up protocols. Purpose To systematically evaluate the safety and efficacy of SVB for IA treatment. Data sources PubMed, Scopus, and Web of Science were searched following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)guidelines. Study selection Studies were included if they reported ≥5 patients with IAs treated with SVB, and provided clinical and angiographic outcome data. Data analysis Efficacy endpoints included adequate/complete occlusion and retreatment rates. Safety outcomes included good functional outcome (modified Rankin Scale score of 0–2), procedure related complications, morbidity, mortality, in-stent stenosis, and covered branch occlusion. Pooled proportions with 95% CIs were calculated using a random effects model. Results 14 observational studies (13 retrospective; one prospective) including 653 patients (65.4% women; mean age 55.3±4.4 years) with 673 aneurysms were included. Most aneurysms were unruptured (59.6%). Adequate and complete occlusion at the last follow-up was 82.68% (95% CI 75.52 to 89.85) and 71.39% (95% CI 60.78 to 82.00), respectively. Retreatment occurred in 1.46% (95% CI 0.00 to 3.16). Good functional outcome was reported in 92.90% of cases. Procedure related complications occurred in 9.32%, with 0.53% morbidity and 0.37% mortality. In-stent stenosis occurred in 7.18% of cases. Immediate covered branch occlusion occurred in 5.38% of patients, and covered branch occlusion at follow-up in 17.69%, mostly asymptomatic. Conclusions In observational studies, SVB showed favorable angiographic and clinical outcomes for selected distal intracranial aneurysms. However, the available evidence was limited by retrospective study design, substantial heterogeneity, and variable follow-up, and conclusions, particularly in ruptured aneurysms, and should be interpreted with caution pending prospective comparative data.
• Bhandari, A., Rogers, S. N., Vedantham, S., Wruble, R. J., Udayasankar, U., Ozgur, H., & Mushtaq, R. (2025). MRI evaluation of hyperostosis frontalis interna: differentiation and diagnostic insights. Neuroradiology, 67(Issue 11). doi:10.1007/s00234-025-03708-9
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  Introduction: To delineate the MRI characteristics of Hyperostosis Frontalis Interna (HFI) and evaluate its imaging features to aid in accurate diagnosis and differentiation from other pathologies, particularly metastatic disease. Methods: A retrospective analysis of 74 patients with HFI was conducted. MRI sequences, including pre-contrast T1-weighted, post-contrast T1-weighted, and T2-weighted fat-saturation imaging, were evaluated. Quantitative and qualitative assessments of HFI signal intensity and enhancement patterns were performed. The Hershkovitz classification categorized the extent of HFI. Results: Pre-contrast T1-weighted imaging showed varied signal intensities, with hypointense regions more common in advanced HFI stages. Hypointense HFI was associated with a lower likelihood (OR: 0.303, CI: 0.113–0.808) and heterogeneous distribution was associated with a higher likelihood (OR: 5.128, CI: 1.982–13.265) of higher Hershkovitz classification (P = 0.0008). Post-contrast T1-weighted imaging revealed that 31% of subjects demonstrated enhancement, with focal geographic enhancement associated with lower CT attenuation values (P = 0.0138), indicating higher fat content. T2-weighted fat-saturation imaging supported the correlation between hypointense signals on pre-contrast T1 imaging and lower T2 signal intensities (P = 0.0022). No significant differences were found in enhancement patterns between different MRI sequences (P > 0.1326). Conclusions: HFI demonstrates varying appearances on pre- and post-contrast MRI sequences, crucial for differentiating benign HFI from metastatic lesions. Understanding these imaging characteristics can enhance diagnostic accuracy, reduce the risk of misdiagnosis, and improve patient management. Future studies should focus on larger, more diverse populations and explore advanced MRI techniques to further understand HFI.
• Bhandari, A., Vittoria De Martini, I., Rogers, S. N., Nallagangula, A., & Ozgur, H. (2025). Immunotherapy related endocrinopathy of the pineal and pituitary gland that resolved following discontinuation of treatment: case report. Neuroradiology, 67(Issue 9). doi:10.1007/s00234-025-03687-x
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  Immune checkpoint inhibitors (ICI) have been integrated into various tumor treatment protocols, including melanoma. Endocrinopathies related to ICI have been well-documented, with most common sites of involvement being thyroid, pituitary, adrenal, and pancreas. We report a 65-year-old female with metastatic melanoma who developed endocrinopathy of the pineal gland and pituitary gland following treatment with ICI. Although metastatic disease was considered in the differential diagnosis, the MRI findings in conjunction with resolution upon discontinuation of immunotherapy was most consistent with inflammatory etiology. A comprehensive literature search yielded no reports of immunotherapy-induced endocrinopathy of the pineal gland, suggesting that this may be potentially the first reported case. Understanding the clinical and imaging findings of immune-related adverse events in patients undergoing immunotherapy is crucial to ensure proper diagnosis and subsequent treatment plans.
• Nguyen, A. D., Rayasam, K., Kaimal, G., Ozgur, H., & Rogers, S. N. (2025). Distinguishing Optic Neuritis and Optic Perineuritis: A Pictorial Review. Neurographics, 15(Issue 3). doi:10.3174/ng.2400072
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  Both optic neuritis (ON) and optic perineuritis (OPN) are distinct entities with the idiopathic forms having different clinical presentations, imaging appearances, and treatment courses. Additionally, they are both associated with different diseases, each with different underlying pathophysiology and appropriate management. ON is associated with multiple sclerosis, neuromyelitis optica, and myelin oligodendrocyte glycoprotein antibody–associated disease. OPN is associated with giant cell arteritis and infectious neuritis. In this article, we review these common entities, their etiologies, imaging appearance, mimics, and lesser known vasculitis and rheumatologic associations, to ultimately provide a comprehensive review on ON and OPN. Learning Objective: To describe the distinguishing imaging characteristics of both ON and OPN.
• Ozgur, H. (2024). Extramedullary Plasmacytoma of the Maxillary Sinuses in a Patient With Multiple Myeloma.. OTO Open American Academy of Otolaryngology-Head and Neck Surgery Foundation. doi:doi: 10.1002/oto2.144
• Ramkumar, S. P., Narendran, N., Gallego, C. J., Ozgur, H., Samargandy, S., & Le, C. H. (2025). MRI Versus CT in Acute Invasive Fungal Sinusitis: Mapping Diagnostic Accuracy Across Sinonasal Subsites. International Forum of Allergy and Rhinology. doi:10.1002/alr.70087
• Sheldon, B. L., Brown, J. M., Ozgur, H., & Chua, R. V. (2025). Symptomatic cerebral spinal fluid leak (or intracranial hypotension) due to sacral extradural cyst rupture after sacral fracture: illustrative case. Journal of Neurosurgery: Case Lessons, 9(Issue 24). doi:10.3171/case2555
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  BACKGROUND Intracranial hypotension due to a CSF leak has many possible etiologies including traumatic dural tears, CSF-venous fistulas, iatrogenic causes, and elevated intracranial pressure. An example of traumatic rupture of a preexisting congenital spinal cyst (SC) in the sacrum causing a symptomatic CSF leak has not been described in the literature; therefore, the authors present the case of a 13-year-old female with a previously undiagnosed SC (Nabor type IB, sacral meningocele) found to have symptomatic intracranial hypotension following a ground-level fall. OBSERVATIONS Traumatic rupture of SCs may cause a dural tear, resulting in stigmata of intracranial hypotension. LESSONS SCs are rare entities that are often asymptomatic but should be carefully considered in the differential diagnoses for intracranial hypotension, even following low-impact trauma. Symptoms resolve with definitive treatment of dural tear, and recurrence rates are low.
• Ozgur, H. (2024). Musculoskeletal and CNS coccidiomycosis in an individual with multiple sclerosis on fingolimod.. ID Cases. doi:doi = "10.1016/j.idcr.2024.e02021
• Ozgur, H. (2024). Syndrome of inappropriate antidiuretic hormone release secondary to central nervous system coccidioidomycosis with vasculitis.. BMJ Case Reports. doi:doi: 10.1136/bcr-2023-258915
• Ozgur, H. (2024). A Rare Presentation of Unilateral Idiopathic Hypertrophic Olivary Degeneration . Cureus. doi:DOI: 10.7759/cureus.52251
• Gates, G. F., Aronsky, A., & Özgür, H. T. (2006). Intracardiac Extension of Lung Cancer Demonstrated on PET Scanning. Clinical Nuclear Medicine. doi:10.1097/01.rlu.0000197051.74922.02
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  Intracardiac tumors are unusual and can originate within the heart or spread from other sites. This is a report of a patient who presented with a TIA, and during the subsequent stroke workup, a right hilar nonsmall cell lung carcinoma was discovered. The tumor had extended into the left atrium through a pulmonary vein. The hilar tumor as well as intracardiac extension were demonstrated by PET scanning using FDG.
• Krupinski, E. A., Labadie, E. L., Masaryk, A. M., Melgar, M., Ozgur, H. T., Seeger, J. F., Walsh, T. K., & Williams, W. (2001).

  Correlation of Cerebrovascular Reserve as Measured by Acetazolamide-challenged SPECT with Angiographic Flow Patterns and Intra- or Extracranial Arterial Stenosis

  . American Journal of Neuroradiology.
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  BACKGROUND AND PURPOSE: The ability to identify patients at increased risk for stroke from cerebral hemodynamic ischemia may help guide treatment planning. We tested the correlation between regional cerebrovascular reserve (rCVR) on acetazolamide-challenged single-photon emission CT (SPECT) brain scans and intracranial collateral pathways as well as extra- or intracranial (EC-IC) arterial stenosis on cerebral angiography. METHODS: A retrospective analysis of 27 patients who underwent cerebral angiography and acetazolamide-challenged SPECT brain imaging was performed. With cerebral angiography, the anterior, middle, and posterior cerebral artery (ACA, MCA, PCA) territories were evaluated for patterns of flow, including the ipsilateral carotid or basilar arteries, the circle of Willis collaterals, the EC-IC collaterals, and the leptomeningeal collaterals. With acetazolamide-challenged SPECT, the ACA, MCA, and PCA territories were classified as either showing or not showing evidence of decreased rCVR. Statistical significance was determined by the χ2 test. RESULTS: Patients with decreased rCVR had significantly greater dependence on either the EC-IC or leptomeningeal collaterals (42%) than did patients without decreased rCVR (7%). Similarly, the cerebral hemispheres with decreased rCVR showed a higher prevalence of 70% or greater stenosis or occlusion of the ipsilateral EC-IC arteries in the anterior circulation (74%) than did hemispheres with no evidence of decreased rCVR (16%), and this difference was also statistically significant. CONCLUSION: Acetazolamide-challenged SPECT brain scanning provides additional information regarding rCVR that is not reliably provided by cerebral angiography.
• Borders, G. T., Carmody, R. F., Erly, W. K., Gabaeff, D. R., Ozgur, H. T., Seeger, J. F., & Zaetta, J. M. (2000).

  Gadopentetate dimeglumine as a contrast agent in common carotid arteriography.

  . American Journal of Neuroradiology.
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  BACKGROUND AND PURPOSE: Despite improvements in noninvasive imaging, some patients with contraindications to iodine-based contrast material still require angiography for the evaluation of carotid stenosis. Our aim was to assess the utility of gadopentetate dimeglumine as an intraarterial contrast agent in common carotid angiography. METHODS : Twelve patients with suspected carotid artery stenosis were enrolled in the study. In addition to the standard injection sequences with iohexol, common carotid arteriograms were obtained after administration of gadopentetate dimeglumine. Neurologic status and vital signs were monitored during and for 6 hours after the examination. For each injection, five independent observers, blinded to the contrast agent used, measured the percentage of carotid stenosis and assessed their confidence in grading the stenosis, the overall quality of the examination, and, in cases of decreased quality, the reason(s) for it. Statistical analysis was done with paired and unpaired t -tests with equal variances. RESULTS : No patient had an adverse clinical outcome, and measurements of carotid artery stenosis showed no statistically significant differences between the gadopentetate dimeglumine and iohexol examinations. Overall image quality and observer confidence in measurements of stenosis on the gadolinium-based studies were slightly but significantly lower than those of identical iodine-based studies. CONCLUSION : Gadopentetate dimeglumine may be an alternative to iodine in selected patients undergoing carotid angiography. Although overall image quality of the gadolinium studies is slightly inferior to that of the iohexol studies, measurements of carotid artery stenosis are similar for the two examinations.
• Pereles, F. S., Özgür, H. T., Lund, P. J., & Unger, E. C. (1998). Potentials of a new laser guidance system for percutaneous musculoskeletal procedures. Skeletal Radiology. doi:10.1007/s002560050328
• Pereles, F. S., Özgür, H. T., Lund, P. J., & Unger, E. C. (1998). Potentials of laser guidance system for percutaneous musculoskeletal procedures. Skeletal Radiology. doi:10.1007/s002560050304
• Hulett, R. L., & Ozgur, H. T. (1997).

  Double blind ureteral duplication

  . Pediatric Radiology. doi:10.1007/s002470050183
• Ozgur, H. T., Unger, E. C., & Wright, W. H. (1996).

  Portal venous gas in a cardiac transplant patient.

  . American Journal of Roentgenology. doi:10.2214/ajr.166.4.8610594
• Özgür, H. T., Aytadar, S., & Ozgur, M. (1993). CT and US findings in a rarely seen case of cardiac echinococcosis: A case report. European Radiology. doi:10.1007/bf00167475

Poster Presentations

• Ainapurapu, B. B., Ozgur, H. T., Khona, N., Stillman, J., Gong, X., Huff, T., Baber, K., & Chen, J. (2025).

  A Unique Case of Granulomatosis with Polyangiitis Presenting with Myositis. 

   

  . Poster presented at: 2025 Arizona Chapter Annual Scientific Meeting; Mesa, AZ; 11/2025.