Jai Shankar

University of Manitoba | UMN · Department of Radiology

Women, especially following menopause, are known to have worse outcomes following acute ischemic stroke. One primary postulated biological mechanism for worse outcomes in older women is a reduction in the vasculoprotective effects of estrogen. Using the INTERRseCT cohort, a multicentre international observational cohort studying recana-lization in...

Importance: It is unknown whether intravenous thrombolysis using tenecteplase is noninferior or preferable compared with alteplase for patients with acute ischemic stroke. Objective: To examine the safety and efficacy of tenecteplase compared to alteplase among patients with large vessel occlusion (LVO) stroke. Design, setting, and participants...

Introduction: Cardiac arrest remains one of the most common causes of death with the majority occurring outside of hospitals (out of hospital cardiac arrest). Despite advancements in resuscitation management, approximately 50% of comatose cardiac arrest patients (CCAP) will suffer a severe unsurvivable brain injury. To assess brain injury, a neuro...

Background: The Alteplase compared to Tenecteplase (AcT) randomized controlled trial (RCT) showed that tenecteplase is non-inferior to alteplase in treating acute ischemic stroke within 4.5 hours of symptom onset. The effect of time to treatment on clinical outcomes with alteplase is well known, however the nature of this relationship is yet to be...

Introduction Chronic subdural hematoma (CSDH) is one of the most encountered neurosurgical cases. CSDH is defined as the accumulation of liquified blood products in the space between the dura and the arachnoid. A reported incidence of 17.6/100,000/year has more than doubled in the past 25 years in parallel with an aging population. Surgical drainag...

The purpose of this systematic review was to analyze evidence based on existing studies on the ability of initial CT imaging to predict mortality in severe traumatic brain injuries (TBIs) in pediatric patients. An experienced librarian searched for all existing studies based on the inclusion and exclusion criteria. The studies were screened by two...

Introduction: Termed the "silent epidemic," traumatic brain injury (TBI) is one of the greatest global contributors not only to post-traumatic death but also to post-traumatic long-term disability. This systematic review and meta-analysis aims to specifically evaluate the prognostic value of features on initial imaging completed within 24 h of arr...

Background and aims: Recent evidence from thrombolysis trials indicate the non-inferiority of the Tenecteplase (TNK) to the Alteplase (TPA) with respect to functional outcomes in acute stroke patients. This study examines the predictors of patient-reported health-related quality of life (HRQOL) in acute stroke patients who received thrombolysis the...

Background Intravenous thrombolysis with alteplase is widely used in patients with acute ischemic stroke presenting early after symptom onset. Recent phase II trials have suggested that intravenous tenecteplase may be safer and associated with higher early reperfusion rates as compared with alteplase. This study investigates whether intravenous ten...

Background: Intravenous thrombolysis with alteplase bolus followed by infusion is a global standard of care for patients with acute ischaemic stroke. We aimed to determine whether tenecteplase given as a single bolus might increase reperfusion compared with this standard of care. Methods: In this multicentre, open-label, parallel-group, registry...

Purpose: The goal of this study was to understand the impact of COVID-19 pandemic and associated lockdown measures on the volume, rate, and type of trauma presenting to the emergency department (ED) by using trauma-initiated CT studies to capture patient data. Materials and methods: We performed a retrospective observational study comparing pati...

2041 Background: Patients with glioblastoma are often treated with radiation and chemotherapy following surgery. Disease recurrence often occurs early in the disease course and during initial therapy, yet assessment of treatment response with MRI is highly variable in some situations. We sought to describe the clinical and imaging assessment and ou...

Background : Intravenous thrombolysis with alteplase is widely used in acute ischemic stroke patients presenting early after symptom onset. Recent phase II trials have suggested that intravenous tenecteplase may be safer and associated with higher early reperfusion rates as compared to alteplase. This study investigates whether intravenous tenectep...

Dural arteriovenous fistulas (DAVFs) are direct shunts between extracranial or meningeal arteries and dural sinuses, dural veins, or cortical veins. They account for 10%–15% of all intracranial vascular malformations. DAVFs are classified according to two classification systems, Borden and Cognard, both of which are based on the venous drainage pat...

Background The Low-profile Visible Intraluminal Support device (LVIS Jr) has become a commonly used intracranial stent for the treatment of intracranial aneurysms. However long-term stability and effectiveness remains to be seen. The purpose of the study was to assess the long-term efficacy, safety and durability of LVIS Jr. in a retrospective mult...

Traumatic brain injury is a major catastrophic event occurring primarily in young and healthy population who previously had excellent quality of life. It is estimated that more than 1.7 million cases of TBI occurs in the United States every year and approximately 5.4 billion people live with disabilities because of TBI in the United States alone. T...

Importance Some patients have poor outcomes despite small infarcts after endovascular therapy (EVT), while others with large infarcts do well. Understanding why these discrepancies occur may help to optimize EVT outcomes. Objective To validate exploratory findings from the Endovascular Treatment for Small Core and Anterior Circulation Proximal Occ...

Background and purpose: Various imaging paradigms are used for endovascular treatment (EVT) decision-making and outcome estimation in acute ischemic stroke (AIS). We aim to compare how these imaging paradigms perform for EVT patient selection and outcome estimation. Methods: Prospective multi-center cohort study of patients with AIS symptoms wit...

Background: Collateral status is an indicator of favorable outcome in stroke. Leptomeningeal collaterals provide alternative routes for brain perfusion following an arterial occlusion or flow-limiting stenosis. Using a large cohort of ischemic stroke patients, we examined the relative contribution of various demographic, laboratory and clinical var...

Despite changes in guideline-based management of moderate/severe traumatic brain injury (TBI) over the preceding decades, little impact on mortality and morbidity have been seen. This argues against the “one-treatment fits all” approach to such management strategies. With this, some preliminary advances in the area of personalized medicine in TBI c...

Key points: • Computed tomographic perfusion (CTP) is increasingly being used in the characterization of brain ischemia.• Variations in post-processing protocols continue to be a challenge, resulting in a slight variation of CTP results.• We need to adopt a universal acquisition protocol to help optimize output of CTP.

Background and purpose: Noninvasive angiography is commonly used to assess the outcome of surgical or endovascular treatment of intracranial aneurysms in clinical series or randomized trials. We sought to assess whether a standardized 3-grade classification system could be reliably used to compare the CTA and MRA results of both treatments. Mater...

Hemorrhagic transformation is caused by extravasation of blood products from vessels after acute ischemic stroke. It is an undesirable and potentially devastating complication, which occurs in 10%-40% of clinical cases. Hemorrhagic transformation is classified into four subtypes based on European cooperative acute stroke study II. Predicting hemorr...

Introduction Severe traumatic brain injury (TBI) is a catastrophic neurological condition with significant economic burden. Early in-hospital mortality (<48 hours) with severe TBI is estimated at 50%. Several clinical examinations exist to determine brain death; however, most are difficult to elicit in the acute setting in patients with severe TBI....

Background The effectiveness and safety of endovascular thrombectomy (EVT) for medium vessel occlusions (MeVO) in the anterior intracranial circulation for patients with acute ischemic stroke (AIS) has yet to be definitively established. We compared outcomes in patients undergoing EVT for large vessel occlusion (LVO) versus those with MeVO. Method...

Importance The benefits of endovascular thrombectomy (EVT) are time dependent. Prior studies may have underestimated the time-benefit association because time of onset is imprecisely known. Objective To assess the lifetime outcomes associated with speed of endovascular thrombectomy in patients with acute ischemic stroke due to large-vessel occlusi...

Purpose Endovascular thrombectomy (EVT) significantly improves outcomes for acute ischemic stroke patients with large vessel occlusion (LVO) who present in a time sensitive manner. Prolonged EVT access times may reduce benefits for eligible patients. We evaluated the efficiency of EVT services including EVT rates, onset-to-CTA time and onset-to-gro...

Objective Chronic subdural hematoma (CSDH) is a common and debilitating neurological condition whose treatments, including burr hole drainage and craniotomy, suffer from high rates of recurrence and complication. Embolization of the middle meningeal artery (EMMA) is a promising minimally invasive approach to manage CSDH in a broad set of patients....

Background Orbital and peri-orbital venolymphatic malformations (VLM) are low flow vascular malformations. Intralesional bleomycin is now commonly being used to treat such malformations. Objective The purpose of this systematic review is to synthesize evidence on the safety and efficacy of bleomycin/pingyangmycin sclerotherapy for the treatment of...

Endovascular thrombectomy (EVT) has revolutionized the care of patients with acute ischemic stroke. The efficacy of EVT is dependent on the optimal setup of a stroke system. Extrapolating the results of clinical trials to any individual stroke center should be done with caution. This is more important for centers with suboptimal stroke systems of c...

BACKGROUND According to the updated RANO criteria, MRI contrast enhancement and peritumoral edema during the initial 12 weeks within the radiation field following chemoradiation may be pseudoprogression (PP) or true progression (TP). This ambiguity results in diagnostic uncertainty and delays in effective therapies. MRI perfusion and permeability i...

Background and Purpose Available data on the clinical course of patients with acute ischemic stroke due to medium vessel occlusion (MeVO) are mostly limited to those with M2 segment occlusions. Outcomes are generally better compared with more proximal occlusions, but many patients will still suffer from severe morbidity. We aimed to determine the c...

Study design: Retrospective cohort study. Objective: To examine the relationship between preoperative Modic change (MC) and postoperative clinical assessment scores for patients receiving lumbar discectomy or transforaminal lumbar interbody fusion for lumbar disk herniation. Summary of background data: Lumbar disk herniation is a risk factor f...

The trigeminocardiac reflex is a well-described brainstem reflex that clinically manifests as bradycardia, hypotension, or apnea. This physiological phenomenon is extensively reported during open neurosurgical procedures, but very few data exist for trigeminocardiac reflex occurrence during neurointerventional procedures. This systematic review aim...

Background Venolymphatic malformations are rare benign vascular lesions of the head and neck. Sclerotherapy has become the first-line therapy of these lesions with bleomycin being a sclerosing agent commonly used. Purpose To perform a systematic review of the published literature to synthesize evidence on the safety and efficacy of bleomycin for t...

Background Simulation training has been used in the aviation industry and surgical specialties for many years, but integration into neurointerventional practice is lagging behind. Objective To investigate how neurointerventionalists perceive the usefulness and limitations of simulation tools for the treatment of unruptured intracranial aneurysms (...

Background In the absence of randomized evidence the optimal management of patients with unruptured intracranial aneurysms (UIA) remains uncertain. Methods CAM is an all-inclusive care trial combined with a registry. Any patient with a UIA (no history of intracranial hemorrhage within the previous 30 days) can be recruited and treatment allocation...

Background Whether transverse venous sinus stenosis (TVSS) causes idiopathic intracranial hypertension (IIH) or is an effect of the increased intracranial pressures is controversial. The purpose of this study was to assess the feasibility of serial imaging in patients with IIH on medical management. Methods Patients found to have IIH and TVSS on c...

Purpose: Contrast-enhanced magnetic resonance imaging (CEMRI) of the head is frequently employed in investigations of sensorineural hearing loss (SNHL). The yield of these studies is perceptibly low and seemingly at odds with the aims of wise resource allocation and risk reduction within the Canadian healthcare system. The purpose of our study was...

Arterial recanalization to restore the blood supply and limit the brain damage is the primary goal in the management of acute ischemic stroke (AIS). Since the publication of pivotal randomized clinical trials in 2015, endovascular thrombectomy has become part of the standard of care in selected cases of AIS from large‐vessel occlusions up to 6 hour...

OBJECTIVE. The purposes of this study were to assess the feasibility and safety of perfusion CT of patients with severe traumatic brain injury (TBI) at hospital admission and to examine whether early in-hospital mortality could be characterized with perfusion CT (PCT). The hypothesis was that PCT can be used to characterize brain death, when presen...

Spontaneous intracranial hypotension (SIH) is a significant cause of chronic, postural headaches. Spontaneous intracranial hypotension is generally believed to be associated with cerebrospinal fluid (CSF) leaks, and these leaks can be posttraumatic, iatrogenic, or idiopathic in origin. An integral part of the management of patients with this condit...

Purpose Endovascular thrombectomy (EVT) treatment for acute ischemic stroke is now recommended as a standard of care. However, implementing EVT in routine clinical practice poses many challenges, even in countries with advanced health-care systems. The aim of the current study is to delineate if EVT at our institution is an effective treatment for...

Background and purpose: The impact of increased aneurysm packing density on angiographic outcomes has not been studied in a randomized trial. We sought to determine the potential for larger caliber coils to achieve higher packing densities and to improve the angiographic results of embolization of intracranial aneurysms at 1 year. Materials and m...

Purpose Although several studies have reported imaging findings associated with idiopathic intracranial hypertension (IIH), less is known about the correlation between imaging findings and IIH-related symptoms or signs. Our study aimed to determine if clinical features of IIH are correlated with magnetic resonance imaging (MRI) features. Methods A...

Background: The T2 hypointensity has been suggested to be associated with intracranial metastatic adenocarcinomas (IMA). The purpose of our study was to determine the association of T2 hypointensity with IMA. Methods: All patients with pathologically confirmed metastatic brain tumors who had a magnetic resonance imaging (MRI) at our institution...

Background: Although the efficacy of endovascular thrombectomy (EVT) for acute ischemic stroke caused by intracranial anterior circulation large vessel occlusion (LVO) is proven, demonstration of local effectiveness is critical for health system planning and resource allocation because of the complexity and cost of this treatment. Methods: Using...

Objective: Endovascular thrombectomy (EVT) is efficacious for ischemic stroke caused by proximal intracranial large-vessel occlusion involving the anterior cerebral circulation. However, evidence of its cost-effectiveness, especially in a real-world setting, is limited. We assessed whether EVT ± tissue plasminogen activator (tPA) was cost-effectiv...

Transorbital penetration accounts for one-quarter of the penetrating head injuries (PHIs) in adults and half of those in children. Injuries that traverse (with complete penetration of) the brainstem are often fatal, with survivors rarely seen in clinical practice. Here, the authors describe the case of a 16-year-old male who suffered and recovered...

Background: Clinical trials with percutaneous vertebral augmentation (PVA) for intractable pain from vertebral compression fractures (VCF) have shown variable results. Variation in the outcomes may be related to poor patient selection on imaging. Objective: To assess if PVA augmentation for osteoporotic VCF results in better improvement in pain...

Background The imaging appearance of neoplastic hematoma can be complicated by the presence of a large hematoma, even on magnetic resonance imaging (MRI). We describe the role of MR perfusion (MRP) in detecting neoplastic hematomas in patients with intraparenchymal hematoma (IPH). Material and MethodsA retrospective review was performed for consecu...

Background and purpose: Appropriate management of ruptured intracranial aneurysm (RIA) in patients eligible for surgical clipping but under-represented in or excluded from previous randomized trials remains undetermined. Methods: The International Subarachnoid Aneurysm Trial-2 (ISAT-2) is a randomized care trial comparing surgical versus endovas...

Purpose: To compare the performance of collateral- vs perfusion-based imaging paradigms in late window stroke patients. Methods: In the prospective international (PRove-IT) study, patients had baseline CT head, multi-phase CTA (mCTA) and CTP. Patients presenting 6-24 hours of onset were included. We retrospectively selected patients for EVT based o...

Objective The term anterior communicating (ACom) aneurysm is often broadly used to classify any aneurysm formed on the A1-A2 junction, A1, A2, or ACom arteries. Aneurysm location has been associated with rupture risk, so whether an aneurysm is truly formed on the ACom artery can critically affect treatment decisions. The aim of this study was to re...

Background The efficacy of SILK flow diverters (SFD) in the management of cerebral aneurysms has been established. However, the risk of complications with parent artery occlusion (PAO) remains to be fully elucidated. The purpose of our study was to analyze intracranial aneurysms treated with SFDs and assess for occurrences and potential risk factor...

Background: CT perfusion (CTP) and diffusion or perfusion MRI might assist patient selection for endovascular thrombectomy. We aimed to establish whether imaging assessments of irreversibly injured ischaemic core and potentially salvageable penumbra volumes were associated with functional outcome and whether they interacted with the treatment effe...

Background and purpose: Hemangiopericytoma and meningioma appear similar on routine diagnostic imaging and hence are difficult to distinguish. The purpose of our study was to examine the diffusion weighted imaging (DWI) characteristics of these two types of tumours. Methods: In a retrospective study, each patient with hemangiopericytoma was matc...

Background In patients with subarachnoid haemorrhage (SAH) and a negative finding on CT angiography (CTA), further imaging with digital subtraction angiography (DSA) is commonly performed to identify the source of bleeding. The purpose of this study was to investigate whether negative findings on CTA can reliably exclude aneurysms in patients with...

Background: EVT is now recommended as standard of care for stroke in Canada, but its implementation still poses challenges. We studied the delivery of EVT in our hospital, a participanting site in the ESCAPE trial, which serves the province of Nova Scotia. Methods: Patients who underwent EVT December 2011 – December 2016 were identified prospective...

Background and purpose: In the ESCAPE trial (Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion with Emphasis on Minimizing CT to Recanalization Times), patients with large vessel occlusions and small infarct cores identified with computed tomography (CT)/CT angiography were randomized to endovascular therapy or stan...

BACKGROUND AND PURPOSE Brain death determination (BDD) is primarily a clinical diagnosis, where death is defined as the permanent loss of brainstem function. In scenarios where clinical examinations are inaccurate, ancillary imaging tests are required. The choice of ancillary imaging test is variable, but the common denominator for all of them is t...

Early assessment of the potential for neurological recovery in comatose cardiac arrest patients has been a challenge despite significant evolution in management and imaging techniques. The purpose of study was to determine if the use of CT Perfusion in comatose cardiac arrest patients (CCAP) is feasible and if this technique can predict the likelih...

BACKGROUND AND PURPOSE: The safety and efficacy of endovascular therapy for large-artery stroke in the extended time window is not yet well-established. We performed a subgroup analysis on subjects enrolled within an extended time window in the Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke (ESCAPE) trial. MATERIALS A...

Background Tandem occlusions of the extracranial carotid and intracranial carotid or middle cerebral artery have a particularly poor prognosis without treatment. Several management strategies have been used with no clear consensus recommendations. We examined subjects with tandem occlusions enrolled in the ESCAPE trial and their outcomes. Methods...

Background and purpose: We have found DSA-Dynavision with multiplanar reconstruction very helpful in understanding the complex anatomy and planning of treatment of carotico-cavernous fistulas. The purpose of our study was to examine whether using DSA-Dynavision in pretreatment planning results in better outcome after endovascular treatment of dura...

Objectives: To compare growth patterns of nonfunctioning and prolactin-producing pituitary macroadenomas, and to find whether their specific growth patterns are associated with clinically significant effects on vision. Materials and methods: From our comprehensive provincial neuropituitary registry, we retrospectively identified 35 randomly sele...