Bio

Clinical Focus

  • Radiology

Academic Appointments

  • Clinical Assistant Professor, Radiology

Professional Education

  • Medical Education: University of Illinois at Chicago College of Medicine Urbana (2011) IL
  • Board Certification: American Board of Radiology, Radiology (2017)
  • Fellowship: Barrow Neurological Institute St Josephs Hospital (2017) AZ
  • Residency: The University of Texas Medical School at Houston (2016) TX
  • Internship: The University of Texas Medical School at Houston (2012) TX

Contact

  • Stanford Neuroimaging and Neurointervention 300 Pasteur Dr Rm S031E MC 5105 Stanford, CA 94305
    • Tel: (650) 723-6767
    Fax: (650) 736-1523
  • Office of Student Affairs 251 Campus Dr Rm 323 MSOB Stanford, CA 94305
    • Tel: (217) 390-4326

Publications

All Publications

  • Pearls and Oy-sters: Dural defect repair as treatment for refractory headache from CSF leak. Neurology Chan, T. L., Kim, D. D., Hashmi, S., Carrol, I. 2020

    View details for DOI 10.1212/WNL.0000000000010476

    View details for PubMedID 32753442

  • Imaging Anatomy of the Vertebral Canal for Trans-Sacral Hiatus Puncture of the Lumbar Cistern. Clinical anatomy (New York, N.Y.) Trinh, A., Hashmi, S. S., Massoud, T. F. 2020

    Abstract

    A standard lumbar puncture may be impossible for many anatomic or technical reasons. Previous accounts of caudal epidural anesthesia and other procedures via the sacral hiatus prompted us to test if image-guided percutaneous trans-sacral hiatus access to the lumbosacral subarachnoid cistern would be anatomically feasible. To study vertebral canal morphometry and curvature, we analyzed midsagittal CT-myelogram images of 40 normal subjects and digitally measured sacral curvatures between S1 to S5 and S2 to S4 using two methods whereby a lower angle signifies a straighter sacrum. We measured midsagittal vertebral canal area, hiatus width, dural sac termination levels, and distance from sacral hiatus to the dural sac tip (needle distance). Subjects were F:M=25:15, with a mean age of 44.9years. The two S1-S5 full sacral curvature mean angles were 57.3° and 60.4°. Almost all sacral hiatuses were at S4, and dural sac terminations were at S1-S2. The mean S2-S4 sacral curvature was 25.1°, and the mean needle distance was 57.7mm. Using two-way ANOVA, there were significant sex differences for needle distances (p=.001), and full and limited sacral curvatures (p=.02, and p=.046, respectively). There were no significant linear regression correlations between age and sacral curvature, needle distance, canal area, or hiatus width. Therefore, despite a frequently prominent full sacral curvature, the combination of S1-S2 dural sac termination plus a relatively straight trajectory of the lower vertebral canal between S2 and S4 support the theoretical feasibility of percutaneous trans-sacral hiatus and vertebral canal access to the lumbosacral cistern using a standard spinal needle. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1002/ca.23612

    View details for PubMedID 32323367

  • Cerebrospinal Fluid Leak in the context of Pars Interarticularis Fracture: A Case Series Chan, L., Cowan, R., Hindiyeh, N., Hashmi, S., Lanzman, B., Carroll, I. LIPPINCOTT WILLIAMS & WILKINS. 2020

    View details for Web of Science ID 000536058001010

  • A within-coil optical prospective motion-correction system for brain imaging at 7T. Magnetic resonance in medicine DiGiacomo, P. n., Maclaren, J. n., Aksoy, M. n., Tong, E. n., Carlson, M. n., Lanzman, B. n., Hashmi, S. n., Watkins, R. n., Rosenberg, J. n., Burns, B. n., Skloss, T. W., Rettmann, D. n., Rutt, B. n., Bammer, R. n., Zeineh, M. n. 2020

    Abstract

    Motion artifact limits the clinical translation of high-field MR. We present an optical prospective motion correction system for 7 Tesla MRI using a custom-built, within-coil camera to track an optical marker mounted on a subject.The camera was constructed to fit between the transmit-receive coils with direct line of sight to a forehead-mounted marker, improving upon prior mouthpiece work at 7 Tesla MRI. We validated the system by acquiring a 3D-IR-FSPGR on a phantom with deliberate motion applied. The same 3D-IR-FSPGR and a 2D gradient echo were then acquired on 7 volunteers, with/without deliberate motion and with/without motion correction. Three neuroradiologists blindly assessed image quality. In 1 subject, an ultrahigh-resolution 2D gradient echo with 4 averages was acquired with motion correction. Four single-average acquisitions were then acquired serially, with the subject allowed to move between acquisitions. A fifth single-average 2D gradient echo was acquired following subject removal and reentry.In both the phantom and human subjects, deliberate and involuntary motion were well corrected. Despite marked levels of motion, high-quality images were produced without spurious artifacts. The quantitative ratings confirmed significant improvements in image quality in the absence and presence of deliberate motion across both acquisitions (P < .001). The system enabled ultrahigh-resolution visualization of the hippocampus during a long scan and robust alignment of serially acquired scans with interspersed movement.We demonstrate the use of a within-coil camera to perform optical prospective motion correction and ultrahigh-resolution imaging at 7 Tesla MRI. The setup does not require a mouthpiece, which could improve accessibility of motion correction during 7 Tesla MRI exams.

    View details for DOI 10.1002/mrm.28211

    View details for PubMedID 32077521

  • Spinal cerebrospinal fluid leak in the context of pars interarticularis fracture. BMC neurology Chan, T. L., Cowan, R. n., Hindiyeh, N. n., Hashmi, S. n., Lanzman, B. n., Carroll, I. n. 2020; 20 (1): 162

    Abstract

    Spinal cerebrospinal fluid (CSF) leak can lead to intracranial hypotension and is an important differential diagnosis to consider in patients with sudden-onset chronic daily headaches. Pars interarticularis (PI) fracture is a potential rare cause of suspected spinal CSF leak.This is a retrospective case series of 6 patients with suspected spinal CSF leak evaluated between January 2016 and September 2019. All patients received a magnetic resonance imaging (MRI) of the brain with and without gadolinium, MRI whole spine and full spine computed tomography (CT) myelogram. Targeted epidural patches with fibrin sealant were performed. Treatment response at return visit (3?months post-patch) was documented.Six patients (4 females, 2 males) were diagnosed with a suspected spinal CSF leak and PI fracture. Mean age at the time of headache onset was 39?years old, and a range from 32 to 50?years old. Mean time to targeted epidural patches with fibrin sealant was 4.5?years. All 6 patients had PI fractures identified on CT myelogram and received targeted epidural patches with fibrin sealant at the site of the PI fracture. All patients had significant improvement in their headache intensity.Our study highlights: 1) the importance of PI fracture as a possible culprit of suspected spinal CSF leak in patients with intracranial hypotension; 2) the added benefit of CT imaging for detecting bony abnormalities such as fractures in patients with intracranial hypotension; and 3) the successful treatment of suspected spinal CSF leak when targeting the fracture site.

    View details for DOI 10.1186/s12883-020-01740-1

    View details for PubMedID 32349710

  • MR Diffusion Concepts and Value in Brain Imaging Glioblastoma: State-of-the-Art Clinical Neuroimaging Hsu, K., Liu, X., Singh, R., Hashmi, S., Iv, M. 2019
  • Structural MRI and CT Features of Glioblastomas and Differential Diagnosis Glioblastoma: State-of-the-Art Clinical Neuroimaging Yoon, B., Liu, X., Singh, R., Hashmi, S., Iv, M. 2019
  • Central Nervous System and Head and Neck Histiocytoses: A Comprehensive Review on the Spectrum of Imaging Findings. Neurographics (2011) Hashmi, S. S., Guha-Thakurta, N. n., Ketonen, L. n., Williams, M. D., Shah, S. n., Debnam, J. M. 2016; 6 (2): 114?22

    Abstract

    The histiocytoses are a rare group of varied but related disorders characterized by abnormal tissue proliferation of macrophages and dendritic cells within tissues. The purpose of this article was to review the imaging findings in patients presenting with CNS and with head and neck manifestations of these disorders. Histiocytoses include but are not limited to Rosai-Dorfman disease, Erdheim Chester disease, Langerhans cell histiocytosis, histiocytic sarcoma, and juvenile xanthogranuloma. A review of the literature was performed to determine the sites of disease involvement. This article includes the demographics, histopathologic criteria for diagnosis, and imaging features of these histiocytoses, and describes the manifestations in locations known to harbor disease: intraaxial and extra-axial intracranial regions, the calvaria, skull base, hypothalamopituitary axis, orbits, paranasal sinuses, spine, and the head and neck region. Histiocytoses have variable imaging appearances in the CNS and in the head and neck region, and radiologists should be aware of the spectrum of findings to avoid mistaking them for other disease processes.To understand the general pathophysiology, clinical presentation, and typical imaging characteristics of the most common histiocytoses; comprehend the morphologic and immunohistochemical characteristics of these histiocytoses and the hallmark findings on pathology; and be able to differentiate between these disorders based on their most common presentations.

    View details for DOI 10.3174/ng.2160150

    View details for PubMedID 30417172

    View details for PubMedCentralID PMC6221469

  • Multicenter imaging outcomes study of The Cancer Genome Atlas glioblastoma patient cohort: imaging predictors of overall and progression-free survival. Neuro-oncology Wangaryattawanich, P., Hatami, M., Wang, J., Thomas, G., Flanders, A., Kirby, J., Wintermark, M., Huang, E. S., Bakhtiari, A. S., Luedi, M. M., Hashmi, S. S., Rubin, D. L., Chen, J. Y., Hwang, S. N., Freymann, J., Holder, C. A., Zinn, P. O., Colen, R. R. 2015; 17 (11): 1525-1537

    Abstract

    Despite an aggressive therapeutic approach, the prognosis for most patients with glioblastoma (GBM) remains poor. The aim of this study was to determine the significance of preoperative MRI variables, both quantitative and qualitative, with regard to overall and progression-free survival in GBM.We retrospectively identified 94 untreated GBM patients from the Cancer Imaging Archive who had pretreatment MRI and corresponding patient outcomes and clinical information in The Cancer Genome Atlas. Qualitative imaging assessments were based on the Visually Accessible Rembrandt Images feature-set criteria. Volumetric parameters were obtained of the specific tumor components: contrast enhancement, necrosis, and edema/invasion. Cox regression was used to assess prognostic and survival significance of each image.Univariable Cox regression analysis demonstrated 10 imaging features and 2 clinical variables to be significantly associated with overall survival. Multivariable Cox regression analysis showed that tumor-enhancing volume (P = .03) and eloquent brain involvement (P < .001) were independent prognostic indicators of overall survival. In the multivariable Cox analysis of the volumetric features, the edema/invasion volume of more than 85 000 mm(3) and the proportion of enhancing tumor were significantly correlated with higher mortality (Ps = .004 and .003, respectively).Preoperative MRI parameters have a significant prognostic role in predicting survival in patients with GBM, thus making them useful for patient stratification and endpoint biomarkers in clinical trials.

    View details for DOI 10.1093/neuonc/nov117

    View details for PubMedID 26203066

  • Percutaneous Cholecystostomy for Acute Cholecystitis: Ten-Year Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Joseph, T., Unver, K., Hwang, G. L., Rosenberg, J., Sze, D. Y., Hashimi, S., Kothary, N., Louie, J. D., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M. 2012; 23 (1): 83-88

    Abstract

    To review the clinical course of patients with acute cholecystitis treated by percutaneous cholecystostomy, and to identify risk factors retrospectively that predict outcome.A total of 106 patients diagnosed with acute cholecystitis were treated by percutaneous cholecystostomy during a 10-year period. Seventy-one (67%) presented to the emergency department (ED) specifically for acute cholecystitis, and 35 (23%) were inpatients previously admitted for other conditions. Outcomes of the two groups were compared with respect to severity of illness, leukocytosis, bile culture, liver function tests, imaging features, time intervals from onset of symptoms to medical and percutaneous intervention, and whether surgical cholecystectomy was later performed.Overall, 72 patients (68%) showed an improvement clinically, whereas 34 (32%) showed no improvement or a clinically worsened condition after cholecystostomy. Patients who presented to the ED primarily with acute cholecystitis fared better (84% of patients showed improvement) than inpatients (34% showed improvement; P < .0001). Gallstones were identified in 54% of patients who presented to the ED, whereas acalculous cholecystitis was more commonly diagnosed in inpatients (54%). Patients with sepsis had worse outcomes overall (P < .0001). Bacterial bile cultures were analyzed in 95% of patients and showed positive results in 52%, with no overall effect on outcome. There was no correlation between the time of onset of symptoms until antibiotic therapy or cholecystostomy in either group. Long-term outcomes for both groups were better for those who later underwent cholecystectomy (P < .0001).Outcomes after percutaneous cholecystostomy for acute cholecystitis are better when the disease is primary and not precipitated by concurrent illness.

    View details for DOI 10.1016/j.jvir.2011.09.030

    View details for PubMedID 22133709

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