Bio

Clinical Focus


  • Radiology

Academic Appointments


  • Clinical Assistant Professor, Radiology

Professional Education


  • Fellowship:Stanford University Radiology Fellowships (2016) CA
  • Fellowship:Stanford University Radiology Fellowships (2014) CA
  • Board Certification: Radiology, American Board of Radiology (2013)
  • Residency:Beth Israel Deaconess Medical Center Radiology Residency (2013) MA
  • Residency:Stanford University Radiology Residency (2010) CA
  • Internship:Mary Hitchcock Memorial Hospital (2009) NH
  • Medical Education:Dartmouth Geisel School of Medicine Office of the Registrar (2008) NH

Publications

All Publications


  • Early Cerebral Vein After Endovascular Ischemic Stroke Treatment Predicts Symptomatic Reperfusion Hemorrhage STROKE Cartmell, S. D., Ball, R. L., Kaimal, R., Telischak, N. A., Marks, M. P., Do, H. M., Dodd, R. L., Albers, G. W., Lansberg, M. G., Heit, J. J. 2018; 49 (7): 1741?46
  • Sofia intermediate catheter and the SNAKE technique: safety and efficacy of the Sofia catheter without guidewire or microcatheter construct. Journal of neurointerventional surgery Heit, J. J., Wong, J. H., Mofaff, A. M., Telischak, N. A., Dodd, R. L., Marks, M. P., Do, H. M. 2018; 10 (4): 401?6

    Abstract

    Neurointerventional surgeries (NIS) benefit from supportive endovascular constructs. Sofia is a soft-tipped, flexible, braided single lumen intermediate catheter designed for NIS. Sofia advancement from the cervical to the intracranial circulation without a luminal guidewire or microcatheter construct has not been described.To evaluate the efficacy and safety of the new Sofia Non-wire Advancement techniKE (SNAKE) for advancement of the Sofia into the cerebral circulation.Consecutive patients who underwent NIS using Sofia were identified. Patient information, SNAKE use, and patient outcome were determined from electronic medical records. Sofia advancement to the cavernous internal carotid artery or the V2/V3 segment junction of the vertebral artery was the primary outcome measure. Secondary outcomes included arterial vasospasm and arterial dissection.263 Patients (181 females, 69%) who underwent a total of 305 NIS using Sofia were identified. SNAKE (SNAKE+) was used in 187 procedures (61%). Two hundred and ninety-three procedures (96%) were technically successful, which included 184 SNAKE+ NIS and 109 SNAKE- NIS. Primary outcome was achieved in all SNAKE+ procedures, but not in five SNAKE- procedures (2%). No arterial dissections were identified among 305 interventions. In the intracranial circulation, a single SNAKE+ patient (0.5%) had non-flow limiting arterial vasospasm involving the petrous internal carotid. Three SNAKE+ patients (1.6%) and one SNAKE- patient (0.8%) demonstrated external carotid artery branch artery vasospasm during dural arteriovenous fistula or facial arteriovenous malformation treatment.SNAKE is a safe and effective technique for Sofia advancement. Sofia is a highly effective and safe intermediate catheter for a variety of NIS.

    View details for PubMedID 28768818

  • Early Cerebral Vein After Endovascular Ischemic Stroke Treatment Predicts Symptomatic Reperfusion Hemorrhage. Stroke Cartmell, S. C., Ball, R. L., Kaimal, R., Telischak, N. A., Marks, M. P., Do, H. M., Dodd, R. L., Albers, G. W., Lansberg, M. G., Heit, J. J. 2018

    Abstract

    Parenchymal hemorrhage (PH) after endovascular mechanical thrombectomy in acute ischemic stroke leads to worse outcomes. Better clinical and imaging biomarkers of symptomatic reperfusion PH are needed to identify patients at risk. We identified clinical and imaging predictors of reperfusion PH after endovascular mechanical thrombectomy with attention to early cerebral veins (ECVs) on postreperfusion digital subtraction angiography.We performed a retrospective cohort study of consecutive acute ischemic stroke patients undergoing endovascular mechanical thrombectomy at our neurovascular referral center. Clinical and imaging characteristics were collected from patient health records, and random forest variable importance measures were used to identify predictors of symptomatic PH. Predictors of secondary outcomes, including 90-day mortality, functional dependence (modified Rankin Scale score, >2), and National Institutes of Health Stroke Scale shift, were also determined. Diagnostic test characteristics of ECV for symptomatic PH were determined using a receiver operating characteristic analysis. Differences between patients with and without symptomatic PH were assessed with Fisher exact test and the Wilcoxon rank sum (Mann-Whitney U test) test at the 0.05 significance level.Of 64 patients with anterior circulation large-vessel occlusion identified, 6 (9.4%) developed symptomatic PH. ECV was the strongest predictor of symptomatic PH with more than twice the importance of the next best predictor, male sex. Although ECV was also predictive of 90-day mortality and functional dependence, other characteristics were more important than ECV for these outcomes. The sensitivity and specificity of ECV alone for subsequent hemorrhage were both 0.83, with an area under the curve of 0.83 and 95% confidence interval of 0.66 to 1.00.ECV on postendovascular mechanical thrombectomy digital subtraction angiography is highly diagnostic of subsequent symptomatic reperfusion hemorrhage in this data set. This finding has important implications for post-treatment management of blood pressure and anticoagulation.

    View details for PubMedID 29739912

  • Fluoroscopic C-Arm and CT-Guided Selective Radiofrequency Ablation for Trigeminal and Glossopharyngeal Facial Pain Syndromes. Pain medicine (Malden, Mass.) Telischak, N. A., Heit, J. J., Campos, L. W., Choudhri, O. A., Do, H. M., Qian, X. 2017

    Abstract

    ?Percutaneous radiofrequency ablation (RFA) of the gasserian ganglion through the foramen ovale and the glossopharyngeal nerve at the jugular foramen is a classical approach to treating trigeminal neuralgia (TN) and glossopharyngeal neuralgia (GPN), respectively. However, it can be technically challenging with serious complications. We have thus developed a novel technique utilizing C-arm and computerized tomography (CT) guidance to block TN and GPN. Our goals were to describe a three-dimensional image-based technique to improve patient comfort and to decrease procedural time associated with needle guidance.Consecutive procedures were reviewed.?Academic hospital.Three patients with classical TN and GPN and 15 patients with atypical facial pain (AFP) were treated. Numeric rating scale (NRS) scores for pain at pretreatment and at one, three, and 12?months post-treatment were recorded. The primary clinical outcome (50% or more reduction in NRS) and secondary adverse clinical outcome (hematoma, facial numbness, etc.) were monitored.?We had a 100% technical success with respect to appropriate needle positioning. All three classical TN/GPN patients had both immediate and sustained pain relief. Complications were minimal. The 15 AFP patients, however, showed more variable results, with only five (33%) having sustained pain relief, while in the other 10 (67%) patients, we observed suboptimal response.?We present a novel method and single-center experience with C-arm and CT-guided RFA of facial pain. Quick and accurate needle placement will help future advancements in the RFA algorithm so that more durable and consistent effects can be attained, reducing uncertainty with respect to needle placement as a confounder. The RFA procedure in our study had a satisfying effect for classical TN/GPN patients but was less successful for AFP patients, though it did mirror the results from previous studies.This study is limited by its small sample size and nonrandomized design.

    View details for DOI 10.1093/pm/pnx088

    View details for PubMedID 28472393

  • Pipeline embolization device retraction and foreshortening after internal carotid artery blister aneurysm treatment. Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences Heit, J. J., Telischak, N. A., Do, H. M., Dodd, R. L., Steinberg, G. K., Marks, M. P. 2017; 23 (6): 614?19

    Abstract

    Background Subarachnoid hemorrhage (SAH) secondary to rupture of a blister aneurysm (BA) results in high morbidity and mortality. Endovascular treatment with the pipeline embolization device (PED) has been described as a new treatment strategy for these lesions. We present the first reported case of PED retraction and foreshortening after treatment of a ruptured internal carotid artery (ICA) BA. Case description A middle-aged patient presented with SAH secondary to ICA BA rupture. The patient was treated with telescoping PED placement across the BA. After 5 days from treatment, the patient developed a new SAH due to re-rupture of the BA. Digital subtraction angiography revealed an increase in caliber of the supraclinoid ICA with associated retraction and foreshortening of the PED that resulted in aneurysm uncovering and growth. Conclusions PED should be oversized during ruptured BA treatment to prevent device retraction and aneurysm regrowth. Frequent imaging follow up after BA treatment with PED is warranted to ensure aneurysm occlusion.

    View details for PubMedID 28758549

  • Clinical and Arterial Spin Labeling Brain MRI Features of Transitional Venous Anomalies. Journal of neuroimaging : official journal of the American Society of Neuroimaging Zhang, M., Telischak, N. A., Fischbein, N. J., Steinberg, G. K., Marks, M., Zaharchuk, G., Heit, J. J., Iv, M. 2017

    Abstract

    Transitional venous anomalies (TVAs) are rare cerebrovascular lesions that resemble developmental venous anomalies (DVAs), but demonstrate early arteriovenous shunting on digital subtraction angiography (DSA) without the parenchymal nidus of arteriovenous malformations (AVMs). We investigate whether arterial spin labeling (ASL) magnetic resonance imaging (MRI) can distinguish brain TVAs from DVAs and guide their clinical management.We conducted a single-center retrospective review of patients with brain parenchymal DVA-like lesions with increased ASL signal on MRI. Clinical histories and follow-up information were obtained. Two readers assessed ASL signal location relative to the vascular lesion on MRI and, if available, the presence of arteriovenous shunting on DSA.Thirty patients with DVA-like lesions with increased ASL signal were identified. Clinical symptoms prompted MRI evaluation in 83%. Symptoms did not localize to the venous anomaly in 90%. Ten percent presented with acute symptoms, only one of whom presented with hemorrhage. ASL signal in relation to the venous anomaly was identified in: 50% in the adjacent parenchyma, 33% in the lesion, 7% in a distal draining vein/sinus, and 10% in at least two of these sites. Follow-up DSA confirmed arteriovenous shunting in 71% of ASL-positive venous anomalies. Interrater agreement was very good (? = .81-1.0, P < .001).A DVA-like lesion with increased ASL signal likely represents a TVA with arteriovenous shunting. Our study indicates that these lesions are usually incidentally detected and have a lower risk of hemorrhage than AVMs. ASL-MRI may be a useful tool to identify TVAs and guide further management of patients with TVAs.

    View details for PubMedID 29205641

  • Headway Duo microcatheter for cerebral arteriovenous malformation embolization with n-BCA. Journal of neurointerventional surgery Heit, J. J., Faisal, A. G., Telischak, N. A., Choudhri, O., Do, H. M. 2016; 8 (11): 1181-1185

    Abstract

    Cerebral arteriovenous malformations (AVMs) are uncommon vascular lesions, and hemorrhage secondary to AVM rupture results in significant morbidity and mortality. AVMs may be treated by endovascular embolization, and technical advances in microcatheter design are likely to improve the success and safety of endovascular embolization of cerebral AVMs.To describe our early experience with the Headway Duo microcatheter for embolization of cerebral AVMs with n-butyl-cyanoacrylate (n-BCA).Consecutive patients treated by endovascular embolization of a cerebral AVM with n-BCA delivered intra-arterially through the Headway Duo microcatheter (167?cm length) were identified. Patient demographic information, procedural details, and patient outcome were determined from electronic medical records.Ten consecutive patients undergoing cerebral AVM embolization using n-BCA injected through the Headway Duo microcatheter were identified. Presenting symptoms included headache, hemorrhage, seizures, and weakness. Spetzler Martin grades ranged from 1 to 5, and AVMs were located in the basal ganglia (2 patients), parietal lobe (4 patients), frontal lobe (1 patient), temporal lobe (1 patient), an entire hemisphere (1 patient), and posterior fossa (1 patient). 50 arterial pedicles were embolized, and all procedures were technically successful. There was one post-procedural hemorrhage that was well tolerated by the patient, and no other complications occurred. Additional AVM treatment was performed by surgery and radiation therapy.The Headway Duo microcatheter is safe and effective for embolization of cerebral AVMs using n-BCA. The trackability and high burst pressure of the Headway Duo make it an important and useful tool for the neurointerventionalist during cerebral AVM embolization.

    View details for DOI 10.1136/neurintsurg-2015-012094

    View details for PubMedID 26603031

  • Initial experience with SOFIA as an intermediate catheter in mechanical thrombectomy for acute ischemic stroke. Journal of neurointerventional surgery Wong, J. H., Do, H. M., Telischak, N. A., Moraff, A. M., Dodd, R. L., Marks, M. P., Ingle, S. M., Heit, J. J. 2016

    Abstract

    The benefits of mechanical thrombectomy for emergent large vessel occlusion (ELVO) have been established. Combined mechanical/aspiration (Solumbra) and a direct aspiration as a first pass technique (ADAPT) are valid procedures requiring an intermediate catheter for clot suction. Recently, SOFIA (Soft torqueable catheter Optimized For Intracranial Access) was developed as a single lumen flexible catheter with coil and braid reinforcement, but its suitability for mechanical thrombectomy had not been evaluated.To describe our initial experience with SOFIA in acute stroke intervention and evaluate its efficacy and safety.All patients with ELVO undergoing endovascular stroke intervention with SOFIA were identified. Demographic, presentation, treatment, and complication data were recorded. Primary outcome was Thrombolysis in Cerebral Infarction (TICI) 2b/3 revascularization rate and the number of passes required. Secondary outcomes included complication rates and discharge National Institute of Health Stroke Scale (NIHSS) score.33 patients with a mean age of 72?years were treated for ELVO with SOFIA and IV tissue plasminogen activator was administered in 67%. Vessel occlusion involved the internal carotid artery (15.2%), M1 (48.5%), and M2 (24.2%) segments, and posterior circulation (12.1%). Median presentation NIHSS score was 14 (IQR 11-19) and discharge NIHSS 4 (IQR 2-14). The Solumbra technique represented 94% of treatments and ADAPT 3%. The TICI 2b/3 revascularization rate was 94%, including 48.5% TICI 3 with an average of 1.6 passes. The symptomatic reperfusion hemorrhage rate was 6%. Procedural complications occurred in four patients, but were unrelated to SOFIA. Mortality was 21%, secondary to failed revascularization, hemorrhagic transformation, and baseline medical condition.Mechanical and aspiration thrombectomy with SOFIA is safe and effective with high revascularization rates. Its trackability, stability, and luminal size make SOFIA suitable for stroke intervention.

    View details for DOI 10.1136/neurintsurg-2016-012750

    View details for PubMedID 27789787

  • Cerebral vascular findings in PAPA syndrome: cerebral arterial vasculopathy or vasculitis and a posterior cerebral artery dissecting aneurysm. Journal of neurointerventional surgery Khatibi, K., Heit, J. J., Telischak, N. A., Elbers, J. M., Do, H. M. 2016; 8 (8)

    Abstract

    A young patient with PAPA (pyogenic arthritis, pyoderma gangrenosum, and acne) syndrome developed an unusual cerebral arterial vasculopathy/vasculitis (CAV) that resulted in subarachnoid hemorrhage from a ruptured dissecting posterior cerebral artery (PCA) aneurysm. This aneurysm was successfully treated by endovascular coil sacrifice of the affected segment of the PCA. The patient made an excellent recovery with no significant residual neurologic deficit.

    View details for DOI 10.1136/neurintsurg-2015-011753.rep

    View details for PubMedID 26122324

  • Arterial Spin Labeling MRI: Clinical Applications in the Brain JOURNAL OF MAGNETIC RESONANCE IMAGING Telischak, N. A., Detre, J. A., Zaharchuk, G. 2015; 41 (5): 1165-1180

    Abstract

    Visualization of cerebral blood flow (CBF) has become an important part of neuroimaging for a wide range of diseases. Arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) sequences are increasingly being used to provide MR-based CBF quantification without the need for contrast administration, and can be obtained in conjunction with a structural MRI study. ASL MRI is useful for evaluating cerebrovascular disease including arterio-occlusive disease, vascular shunts, for assessing primary and secondary malignancy, and as a biomarker for neuronal metabolism in other disorders such as seizures and neurodegeneration. In this review we briefly outline the various ASL techniques including advantages and disadvantages of each, methodology for clinical interpretation, and clinical applications with specific examples.

    View details for DOI 10.1002/jmri.24751

    View details for Web of Science ID 000353641600003

    View details for PubMedID 25236477

  • Clinical applications of iron oxide nanoparticles for magnetic resonance imaging of brain tumors NANOMEDICINE Iv, M., Telischak, N., Feng, D., Holdsworth, S. J., Yeom, K. W., Daldrup-Link, H. E. 2015; 10 (6): 993-1018

    Abstract

    Current neuroimaging provides detailed anatomic and functional evaluation of brain tumors, allowing for improved diagnostic and prognostic capabilities. Some challenges persist even with today's advanced imaging techniques, including accurate delineation of tumor margins and distinguishing treatment effects from residual or recurrent tumor. Ultrasmall superparamagnetic iron oxide nanoparticles are an emerging tool that can add clinically useful information due to their distinct physiochemical features and biodistribution, while having a good safety profile. Nanoparticles can be used as a platform for theranostic drugs, which have shown great promise for the treatment of CNS malignancies. This review will provide an overview of clinical ultrasmall superparamagnetic iron oxides and how they can be applied to the diagnostic and therapeutic neuro-oncologic setting.

    View details for DOI 10.2217/NNM.14.203

    View details for Web of Science ID 000352806000009

    View details for PubMedID 25867862

  • Cerebral vascular findings in PAPA syndrome: cerebral arterial vasculopathy or vasculitis and a posterior cerebral artery dissecting aneurysm. BMJ case reports Khatibi, K., Heit, J. J., Telischak, N. A., Elbers, J. M., Do, H. M. 2015; 2015

    Abstract

    A young patient with PAPA (pyogenic arthritis, pyoderma gangrenosum, and acne) syndrome developed an unusual cerebral arterial vasculopathy/vasculitis (CAV) that resulted in subarachnoid hemorrhage from a ruptured dissecting posterior cerebral artery (PCA) aneurysm. This aneurysm was successfully treated by endovascular coil sacrifice of the affected segment of the PCA. The patient made an excellent recovery with no significant residual neurologic deficit.

    View details for DOI 10.1136/bcr-2015-011753

    View details for PubMedID 26109622

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