The relative cerebral blood volume (rCBV) < 42% is independently associated with hemorrhagic transformation in anterior circulation large vessel occlusion.

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.

Hypoperfusion intensity ratio to differentiate between stroke etiologies in patients with a large vessel occlusion.

Background: Collateral circulation plays a key role in acute ischemic stroke. We sought to determine the association between the arterial collateral status, estimated by the Hypoperfusion Intensity Ratio (HIR) on perfusion MRI, and stroke etiology in anterior circulation large vessel occlusion (LVO).

Methods: We retrospectively analyzed anterior circulation LVO acute stroke patients with a baseline perfusion MRI performed within 24 h from symptom onset.

Large-Core Ischemic Stroke Endovascular Treatment: A Science Advisory From the American Heart Association.

Several trials of endovascular treatment for patients with large-core acute ischemic stroke have been completed. Whereas future stroke clinical guidelines will provide specific recommendations, this advisory aims to summarize the results of these trials, analyze the commonalities and differences among the studies, and discuss the clinical implications of these new results.

No clear relationship between circadian rhythm and cerebral perfusion parameters in pediatric and early adult populations.

Background: Recent literature suggests circadian rhythm influences cerebral perfusion parameters in adults experiencing an acute large vessel occlusion, but this has never been investigated in the pediatric and young adult populations.

Methods: We queried the United States RAPID Insights database (10/05/2018-09/29/2023) for unique patients between 2 and 25 years with computed tomography perfusion (CTP). Included scans had a minimum ischemic core volume (rCBF <30 %) of >0 cc and a Tmax volume of >0 cc.

Predictors of poor outcome in acute stroke patients with posterior cerebral artery occlusion and medical management.

Background And Aims: The clinical evolution of acute ischemic stroke patients with isolated proximal posterior cerebral artery (PCA) occlusion treated with medical management alone has been poorly described. We aimed to determine the clinical and radiological factors associated with poor functional outcome in this population.

Methods: We conducted a multicenter international retrospective study of consecutive stroke patients with isolated occlusion of the first (P1) or second (P2) segment of PCA admitted within 6 h from symptoms onset in 26 stroke centers in France, Switzerland, and the United States, treated with the best medical management alone.

Prolonged venous transit is associated with lower odds of excellent recovery after reperfusion in anterior large-vessel occlusion stroke.

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.

Prolonged Venous Transit on Perfusion Imaging is Associated with Longer Lengths of Stay in Acute Large Vessel Occlusions.

Background And Purpose: Prolonged venous transit (PVT+) is a marker of venous outflow; it is defined as the presence or absence of time-to-maximum ≥10 seconds timing in either the superior sagittal sinus or torcula. This novel perfusion imaging-based metric has been associated with higher odds of mortality and lower odds of functional recovery. This study aims to assess the relationship between PVT on admission perfusion imaging and length of hospital stay in large vessel occlusion strokes successfully reperfused with mechanical thrombectomy.

Role of Hypoperfusion Intensity Ratio in Vessel Occlusions: A Review on Safety and Clinical Outcomes.

The hypoperfusion intensity ratio (HIR) is a quantitative metric used in vascular occlusion imaging to evaluate the extent of brain tissue at risk due to hypoperfusion. Defined as the ratio of tissue volume with a time-to-maximum (Tmax) of >10 seconds to that of >6 seconds, HIR assists in differentiating between the salvageable penumbra and the irreversibly injured core infarct. This review explores the role of HIR in assessing clinical outcomes and guiding treatment strategies, including mechanical thrombectomy and thrombolytic therapy, for patients with large vessel occlusions (LVOs).

Blood-brain barrier profile pretreatment is associated with hemorrhagic transformation after endovascular reperfusion.

Background: While advances in endovascular thrombectomy (EVT) have led to high reperfusion rates, most patients treated with EVT do not avoid disability. Post-reperfusion hemorrhagic transformation (HT) is a potential target for improving outcomes. This study examined pretreatment blood-brain barrier (BBB) disruption in tissue that would subsequently become part of the final infarct to evaluate its role in post-EVT HT.

Efficacy and Safety of Intravenous Tenecteplase Before Endovascular Thrombectomy for Acute Ischemic Stroke: The Multicenter, Randomized, BRIDGE-TNK Trial Protocol.

Background: Six randomized trials have not detected a difference between intravenous alteplase plus endovascular thrombectomy and endovascular thrombectomy alone in stroke. Tenecteplase, a recombinant human tenecteplase tissue-type plasminogen activator, is a genetically modified variant of alteplase. It is unclear whether the outcomes are different if alteplase is replaced with tenecteplase.

Utility of automated CT perfusion software in acute ischemic stroke with large and medium vessel occlusion.

Background: Early diagnosis of large vessel occlusion (LVO) in acute stroke often requires CT angiography (CTA). Automated CT perfusion (CTP) software, which identifies blood flow abnormalities, enhances LVO diagnosis and patient selection for endovascular thrombectomy (EVT). This study evaluates the sensitivity of automated CTP images in detecting perfusion abnormalities in patients with acute ischemic stroke (AIS) and LVO or medium vessel occlusion (MeVO), compared to CTA.

High Hypoperfusion Intensity Ratio Is Independently Associated with Very Poor Outcomes in Large Ischemic Core Stroke.

Background: Recent advances have highlighted the efficacy of endovascular thrombectomy (EVT) in patients with large ischemic core stroke, yet a significant portion still experience very poor outcomes, defined as a 90-day modified Rankin Score (mRS) of 5-6. This study aims to investigate the hypoperfusion intensity ratio (HIR) as a prognostic imaging parameter for these outcomes.

Methods: In a multicenter retrospective cohort study, data from consecutive patients undergoing EVT for acute ischemic stroke with large vessel occlusion (AIS-LVO) at two comprehensive stroke centers were analyzed.

Early penumbral FLAIR changes predict tissue fate in patients with large vessel occlusions.

Background: In patients with an acute ischemic stroke, the penumbra is defined as ischemic tissue that remains salvageable when reperfusion occurs. However, the expected clinical recovery congruent with penumbral salvage is not always observed.

Aims: We aimed to determine whether the magnetic resonance imaging (MRI)-defined penumbra includes irreversible neuronal loss that impedes expected clinical recovery after reperfusion.

Clinical and perfusion imaging characteristics of acute large vessel occlusion in intracranial atherosclerosis.

Objectives: This study aimed to compare clinical and perfusion imaging profiles in acute ischemic stroke with large vessel occlusion (AIS-LVO) between patients with intracranial atherosclerotic disease (ICAD) and non-ICAD who underwent endovascular treatment (EVT).

Methods: Data from AIS-LVO patients over the anterior circulation undergoing EVT across two stroke centers were retrospectively analyzed. Clinical profiles and perfusion parameters from automated processing of perfusion imaging were compared between ICAD and non-ICAD groups.

Deep venous outflow as a surrogate for collaterals in late-window patients with successful revascularization from the DEFUSE 3 cohort.

Background: Deep venous outflow (VO) may be an important surrogate marker of collateral blood flow in acute ischemic stroke patients with a large vessel occlusion (AIS-LVO). Researchers have yet to determine the relationship between deep VO status in late-window patients and imaging measures of collaterals, which are key in preserving tissue.

Materials And Methods: We performed a multicenter retrospective cohort study on a subset of DEFUSE 3 patients recruited across 38 centers between May 2016 and May 2017 who underwent successful thrombectomy revascularization.

Ischemic core volumes and collateral status have diurnal fluctuations - A retrospective cohort study of 18,137 patients.

Introduction: Recent observations suggest that circadian rhythms are implicated in the timing of stroke onset and the speed of infarct progression. We aimed to replicate these observations in a large, multi-center, automated imaging database.

Methods: The RAPID Insights database was queried from 02/01/2016 to 01/31/2022 for patients with perfusion imaging and automated detection of an ischemic stroke due to a presumed large vessel occlusion.