Publications by authors named "Wintermark M"

Background: Mechanical thrombectomy (MT) is established as an effective treatment for large vessel occlusion strokes, but its efficacy and safety for medium vessel occlusions (MeVOs) remain less clear. This study examines the impact of periprocedural embolization to a new vascular territory (ENT) on clinical outcomes in patients with MeVO stroke treated with MT.

Methods: A multicenter, retrospective analysis was conducted using the MAD-MT (Multicenter Analysis of primary Distal medium vessel occlusions: effect of Mechanical Thrombectomy) registry, including 2122 patients with MeVO stroke w-ho underwent MT between September 2017 and July 2023.

View Article and Find Full Text PDF

The Woven EndoBridge (WEB) device is FDA-approved for the treatment of bifurcation aneurysms. Despite its wide popularity, it has been under scrutiny for its association with potential aneurysm recanalization and retreatment due to device shape modification. This study aims to analyze the shape modification rate of WEB devices and identify factors associated with this phenomenon, as well as its correlation with aneurysm retreatment.

View Article and Find Full Text PDF

Background And Purpose: Endovascular thrombectomy is a standard treatment for acute ischemic stroke due to large-vessel occlusions (AIS-LVO), but a large minority of patients do not achieve successful reperfusion. This study aimed to investigate the hypoperfusion intensity ratio (HIR) as a prognostic biomarker in unsuccessfully reperfused patients with AIS-LVO.

Materials And Methods: A multicenter retrospective cohort study was conducted at 2 comprehensive stroke centers, involving patients with AIS-LVO who underwent endovascular thrombectomy but did not achieve successful reperfusion, defined as a modified TICI score of 0-2a.

View Article and Find Full Text PDF

Background And Purpose: PTSD has been linked to an increased risk of cognitive impairment and dementia, with neuroinflammation, metabolic dysfunction, and neuropathological markers such as beta-amyloid and tau implicated as potential mechanisms. However, the roles of altered functional connectivity and amyloid deposition as biomarkers in the progression of cognitive impairment among PTSD patients remain unclear, with limited and often conflicting evidence from existing neuroimaging studies. This study examines these neuroimaging markers in PTSD patients with and without cognitive impairment to better understand the neurobiological pathways contributing to cognitive decline in PTSD.

View Article and Find Full Text PDF

Background: Brain arteriovenous malformations (AVMs) are abnormal connections between feeding arteries and draining veins, associated with significant risks of haemorrhage, seizures and other neurological deficits. Preoperative embolization is commonly used as an adjunct to microsurgical resection, with the aim of reducing intraoperative complications and improving outcomes. However, the efficacy and safety of this approach remain controversial.

View Article and Find Full Text PDF

Background: Acute ischaemic stroke (AIS) is a leading cause of mortality and disability globally, with volume contracted state (VCS), as indicated by an elevated blood urea nitrogen to creatinine (BUN/Cr) ratio, potentially influencing outcomes. This study investigates the association between VCS and clinical outcomes in patients with AIS due to large vessel occlusion (LVO).

Methods: A retrospective cohort study was conducted involving 298 patients with LVO-AIS from two comprehensive stroke centres.

View Article and Find Full Text PDF
Article Synopsis
  • This study investigates the effects of pre-stroke low-dose aspirin on patients with acute ischemic stroke due to distal medium vessel occlusion undergoing mechanical thrombectomy.
  • Findings show that aspirin users had significantly better functional outcomes and lower mortality rates after treatment, with no increase in bleeding risks.
  • The results suggest that pre-stroke low-dose aspirin could be beneficial and safe for these patients, highlighting the need for more research on this topic.
View Article and Find Full Text PDF

Importance: In the Atrial Cardiopathy and Antithrombotic Drugs in Prevention After Cryptogenic Stroke (ARCADIA) randomized clinical trial, anticoagulation did not prevent recurrent stroke among patients with a recent cryptogenic stroke and atrial cardiopathy. It is unknown whether anticoagulation prevents covert infarcts in this population.

Objective: To test the use of apixaban vs aspirin for prevention of nonlacunar covert infarcts after cryptogenic stroke in patients with atrial cardiopathy.

View Article and Find Full Text PDF

Background: Current randomized controlled trials are investigating the efficacy and safety of mechanical thrombectomy (MT) in patients with medium vessel occlusion (MeVO) stroke. Whether best medical management (MM) is more efficient than unsuccessful vessel recanalization during MT remains unknown.

Methods: This was a retrospective cohort study using data from 37 academic centers across North America, Asia, and Europe between September 2017 and July 2021.

View Article and Find Full Text PDF

Background And Purpose: Prolonged length of stay (LOS) following a stroke is associated with unfavorable clinical outcomes. Factors predicting LOS in medium vessel occlusion (MeVO), impacting up to 40% of acute ischemic stroke (AIS) cases, remain underexplored. This study aims to investigate the predictors of LOS in AIS-MeVO.

View Article and Find Full Text PDF

The cerebral blood volume index (CBV index) is a perfusion-based marker of collateral status. Several real-world data analyses from observational stroke cohorts have established relationships between this parameter and a range of favorable and unfavorable stroke outcomes. In this review, an overview is provided of the CBV index, within the context of thrombectomy-treated large vessel and medium vessel occlusion ischemic strokes.

View Article and Find Full Text PDF

Background And Purpose: Prolonged venous transit (PVT), derived from computed tomography perfusion (CTP) time-to-maximum (T) maps, reflects compromised venous outflow (VO) in acute ischemic stroke due to large vessel occlusion (AIS-LVO). Poor VO is associated with worse clinical outcomes, but pre-treatment markers predictive of PVT are not well described.

Methods: We conducted a retrospective analysis of 189 patients with anterior circulation AIS-LVO who underwent baseline CT evaluation, including non-contrast CT, CT angiography, and CTP.

View Article and Find Full Text PDF

Introduction: The venous outflow profile (VOP) is a crucial yet often overlooked aspect affecting stroke outcomes. It plays a major role in the physiopathology of acute cerebral ischemia, as it accounts for both the upstream arterial collaterals and cerebral microperfusion. This enables it to circumvent the limitations of various arterial collateral evaluation systems, which often fail to consider impaired autoregulation and its impact on cerebral blood flow at the microcirculatory levels.

View Article and Find Full Text PDF

Background: Pretreatment CT perfusion (CTP) marker relative cerebral blood volume (rCBV) < 42% lesion volume has recently shown to predict poor collateral status and poor 90-day functional outcome. However, there is a paucity of studies assessing its association with hemorrhagic transformation (HT). Here, we aim to assess the relationship between rCBV < 42% lesion volume with HT.

View Article and Find Full Text PDF

Purpose: Accurate detection of cerebral microbleeds (CMBs) is important for detection of multiple conditions. However, CMBs can be challenging to identify on MR images, especially for distinguishing CMBs from the mimic of calcification. We performed a comparative reader study to assess the diagnostic performance of two primary MR sequences for differentiating CMBs from calcification.

View Article and Find Full Text PDF

Purpose: Clinical adoption of NK cell immunotherapy is underway for medulloblastoma and osteosarcoma, however there is currently little feedback on cell fate after administration. We propose magnetic particle imaging (MPI) may have applications for the quantitative detection of NK cells.

Procedures: Human-derived NK-92 cells were labeled by co-incubation with iron oxide nanoparticles (VivoTrax™) for 24 h then excess nanoparticles were washed with centrifugation.

View Article and Find Full Text PDF

Background And Purpose: Acute ischemic stroke due to anterior circulation large-vessel occlusion (AIS-LVO) remains a leading cause of disability despite successful reperfusion therapies. Prolonged venous transit (PVT) has emerged as a potential prognostic imaging biomarker in AIS-LVO. We aimed to investigate whether PVT is associated with a decreased likelihood of excellent functional outcome (modified Rankin Scale [mRS] score of 0-1 at 90 days) after successful reperfusion.

View Article and Find Full Text PDF
Article Synopsis
  • The study examined the effectiveness of endovascular therapy (EVT) versus best medical therapy (BMT) for isolated anterior cerebral artery occlusions (ACAo) in acute stroke patients.
  • The analysis involved 108 patients from various countries, comparing outcomes like functional independence at 90 days, with results showing no significant difference in success rates between EVT and BMT.
  • Conclusions indicate that while EVT had a high success rate in procedures, it did not lead to better functional outcomes or lower mortality compared to BMT, suggesting a need for more randomized trials.
View Article and Find Full Text PDF

: Pretreatment CTA-based Cortical Vein Opacification Score (COVES) has been shown to predict good functional outcomes at 90 days in patients with acute ischemic stroke secondary to large vessel occlusion (AIS-LVO). This is thought to be related to its ability to measure collateral status (CS). However, its association with the reference standard test, the DSA-based American Society of Interventional and Therapeutic Neuroradiology (ASITN) collateral score, has yet to be established.

View Article and Find Full Text PDF

Background: No treatment is available to prevent brain oedema, which can occur after a large hemispheric infarction. Glibenclamide has previously been shown to improve functional outcome and reduce neurological or oedema-related death in patients younger than 70 years who were at risk of brain oedema after an acute ischaemic stroke. We aimed to assess whether intravenous glibenclamide could improve functional outcome at 90 days in patients with large hemispheric infarction.

View Article and Find Full Text PDF

Background: Pretreatment computed tomography perfusion parameter relative cerebral blood volume (rCBV) lesion volume has been shown to predict 90-day modified Rankin Scale score in small-core strokes with Alberta Stroke Program Early Computed Tomography Score ≥5, including those with medium-vessel occlusions (mid and distal M2 segment occlusions). Hence, in this study we aim to assess the performance of different rCBV lesion volume thresholds (rCBV <42%, rCBV <38%, and rCBV <34%) with 90-day modified Rankin Scale score including patients with large core (Alberta Stroke Program Early Computed Tomography Score <5) and strictly including only patients with anterior circulation large-vessel occlusion.

Methods And Results: In this retrospective evaluation of our prospectively collected database, inclusion criteria were (1) Computed tomographic angiography confirmed anterior circulation large-vessel occlusion from September 1, 2017, to October 1, 2023; and (2) diagnostic computed tomography perfusion.

View Article and Find Full Text PDF

Background: Sentinel lymph node biopsy (SLNB) is an important cancer diagnostic staging procedure. Conventional SLNB procedures with Tc radiotracers and scintigraphy are constrained by tracer half-life and, in some cases, insufficient image resolution. Here, we explore an alternative magnetic (nonradioactive) image-guided SLNB procedure.

View Article and Find Full Text PDF
Article Synopsis
  • A retrospective study assessed the effectiveness of contrast-enhanced T1-weighted 3D SPACE MRI sequences versus 3D FLASH sequences in detecting brain metastases in patients at a single institution.
  • The evaluation involved a review of cases where both imaging techniques were used, with assessments on factors like the number of lesions detected, image quality, and contrast-to-noise ratio (CNR) by certified neuroradiologists.
  • Results showed that SPACE detected more metastatic lesions and had better image quality and fewer artifacts than FLASH, supporting SPACE as the superior method for brain metastasis detection.
View Article and Find Full Text PDF