Multiparametric Magnetic Resonance Imaging for Prediction of Parenchymal Hemorrhage in Acute Ischemic Stroke After Reperfusion Therapy (original) (raw)
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Advanced imaging improves prediction of hemorrhage after stroke thrombolysis
Annals of Neurology, 2013
Objective-Very low cerebral blood volume (VLCBV), diffusion and hypoperfusion lesion volumes have been proposed as predictors of hemorrhagic transformation following stroke thrombolysis. We aimed to compare these parameters, validate VLCBV in an independent cohort using DEFUSE study data and investigate the interaction of VLCBV with regional reperfusion. Methods-The EPITHET and DEFUSE studies obtained diffusion and perfusion MRI in patients 3-6 hours from onset of ischemic stroke. EPITHET randomized patients to tPA or placebo, and all DEFUSE patients received tPA. VLCBV was defined as CBV<2.5 th percentile of brain contralateral to the infarct. Parenchymal hematoma (PH) was defined using ECASS criteria. Reperfusion was assessed using subacute perfusion MRI co-registered to baseline imaging. Results-In DEFUSE, 69 patients were analyzed including 9 who developed PH. The >2mL VLCBV threshold defined in EPITHET predicted parenchymal hematoma (PH) with 100% sensitivity, 72% specificity, 35% positive predictive value and 100% negative predictive value. Pooling EPITHET and DEFUSE (163 patients including 23 with PH), regression models using VLCBV (p<0.001) and tPA (p=0.02) predicted PH independent of clinical factors better than models using diffusion or Tmax>8sec lesion volumes. Excluding VLCBV in regions without reperfusion improved specificity from 61% to 78% in the pooled analysis.
Very Low Cerebral Blood Volume Predicts Parenchymal Hematoma in Acute Ischemic Stroke
Stroke, 2013
H emorrhagic transformation (HT) is a feared complication of ischemic stroke, especially in the advent of parenchymal hematoma (PH). Lower cerebral blood volume (CBV) may be a marker of HT after revascularization procedure. 1 The aim of our study was to confirm the relationship between the volume of very low CBV (VLCBV) and HT using a European multicenter database (I-KNOW). A secondary objective was to explore the impact of early reperfusion and recanalization on the risk of HT. Methods Patients We analyzed patients from the I-KNOW multicenter study, who underwent sequential MRI assessment for acute anterior circulation stroke (http://www.i-know-stroke.eu). Regional ethics committee approved the protocol, and informed consent was obtained from all patients. MRI Protocol At admission, all patients underwent diffusion-weighted imaging (DWI), fluid-attenuated inversion recovery, T2-weighted gradient echo, time-of-flight MR angiography, and perfusion-weighted imaging. A repeat MRI, using the same sequences, was performed 3 hours after the first scan to assess early reperfusion (3-hour follow-up MRI). Follow-up examinations at day 2 and 1 month were acquired without perfusion-weighted imaging. Image Analysis After motion correction using an in-house developed software, perfusion maps, including CBV, were generated according to the reference method. 2 Using a semiautomated software, masks of the acute DWI lesion and the contralateral hemisphere were generated. All perfusion maps and morphological images were coregistered within subjects using MATLAB 2010b (MathWorks Inc, Natick, MA) and SPM8 (Wellcome Trust Centre for Neuroimaging, University College Background and Purpose-Parenchymal hematoma (PH) may worsen the outcome of patients with stroke. The aim of our study was to confirm the relationship between the volume of very low cerebral blood volume (CBV) and PH using a European multicenter database (I-KNOW). A secondary objective was to explore the impact of early reperfusion and recanalization. Methods-The volume of cerebral tissue with CBV ≤2.5th percentile of the normal hemisphere was calculated within the acute diffusion-weighted imaging lesion. Hemorrhagic transformation was assessed on day 2 MRI according to the European Cooperative Acute Stroke Study II criteria. Recanalization and reperfusion were assessed on 3-hour follow-up MRI. Results-Of the 110 patients, hemorrhagic transformation occurred in 59 patients, including 7 PH. In univariate analysis, the acute National Institutes of Health Stroke Scale score (P=0.002), acute diffusion-weighted imaging lesion volume (P=0.02), and thrombolysis (P=0.03), but not very low CBV (P=0.52), were associated with hemorrhagic transformation. The volume of very low CBV was the only predictor of PH (P=0.007). Early reperfusion and recanalization had no influence on either hemorrhagic transformation or PH. Conclusion-Very low CBV was the only independent predictor of PH in patients with acute stroke.
Predicting cerebral ischemic infarct volume with diffusion and perfusion MR imaging
AJNR. American journal of neuroradiology
Diffusion and perfusion MR imaging have proved useful in the assessment of acute stroke. We evaluated the utility of these techniques in detecting acute ischemic infarction and in predicting final infarct size. Diffusion and hemodynamic images were obtained in 134 patients within a mean of 12.3 hours of onset of acute ischemic stroke symptoms. We retrospectively reviewed patient radiology reports to determine the presence or absence of lesion identification on initial diffusion- (DW) and perfusion-weighted (PW) images. Radiologists were not blinded to the initial clinical assessment. For determination of sensitivity and specificity, the final discharge diagnosis was used as the criterion standard. Neurologists were not blinded to the DW or PW imaging findings. In 81 patients, acute lesions were compared with final infarct volumes. Sensitivities of DW imaging and cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) perfusion parameters were 94%, 74%, 84...
The British journal of radiology, 2020
OBJECTIVES Cerebral blood flow (CBF) measurements after endovascular therapy (EVT) for acute ischemic stroke are important to distinguish early secondary injury related to persisting ischemia from that related to reperfusion when considering clinical response and infarct growth. METHODS We compare reperfusion quantified by the modified Thrombolysis in Cerebral Infarction Score (mTICI) with perfusion measured by MRI dynamic contrast-enhanced perfusion within 5 h of EVT anterior circulation stroke. MR perfusion (rCBF, rCBV, rTmax, rT0) and mTICI scores were included in a predictive model for change in NIHSS at 24 h and diffusion-weighted imaging (DWI) lesion growth (acute to 24 h MRI) using a machine learning RRELIEFF feature selection coupled with a support vector regression. RESULTS For all perfusion parameters, mean values within the acute infarct for the TICI-2b group (considered clinically good reperfusion) were not significantly different from those in the mTICI <2b (clinical...
The Indian journal of medical research, 2014
Recently, several medical societies published joint statements about imaging recommendations for acute stroke and transient ischaemic attack patients. In following with these published guidelines, we considered it appropriate to present a brief, practical and updated review of the most relevant concepts on the MRI assessment of acute stroke. Basic principles of the clinical interpretation of diffusion, perfusion, and MRI angiography (as part of a global MRI protocol) are discussed with accompanying images for each sequence. Brief comments on incidence and differential diagnosis are also included, together with limitations of the techniques and levels of evidence. The purpose of this article is to present knowledge that can be applied in day-to-day clinical practice in specialized stroke units or emergency rooms to attend patients with acute ischaemic stroke or transient ischaemic attack according to international standards.
Journal of neurointerventional surgery, 2014
Parenchymal blood volume (PBV) mapping with flat panel detectors may provide real-time estimates of tissue perfusion during endovascular ischemic stroke procedures. We present two cases of acute middle cerebral artery (MCA) occlusion to demonstrate how PBV may: (1) be used in acute stroke; (2) influence intraprocedural decision-making; and (3) potentially serve as a predicator of clinical outcome. Both cases were successfully recanalized with endovascular embolectomy. Intraprocedural PBV maps were obtained immediately before and after recanalization. Pre-intervention reductions in PBV were seen throughout the MCA territory in both cases, with significant improvement in PBV in one case with good radiographic and clinical outcome and a lack of improvement in PBV in the second case with a large infarct volume. PBV deficit normalization may occur with recanalization of the parent artery and probably represents successful reperfusion. Baseline PBV maps should therefore be interpreted wit...
Prediction of Hemorrhagic Transformation Following Acute Stroke
Archives of Neurology, 2001
Background: Acute diffusion-weighted (DWI) and perfusion-weighted (PWI) magnetic resonance imaging (MRI) findings may correlate with secondary hemorrhagic transformation (HT) risk in patients with stroke. This information could be of value, particularly in individuals being considered for thrombolytic therapy. Objective: To determine the relationship between DWI and PWI findings and the risk of secondary HT in patients with acute stroke. Design: Retrospective case series. Setting: Academic medical center. Patients: Twenty-seven patients with acute stroke capable of being evaluated with DWI/PWI 8 hours or less after symptom onset. Main Outcome Measures: Apparent diffusion coefficient values, perfusion delay measurements, and subsequent MRI or computed tomographic scans detected HT. Results: The mean±SD apparent diffusion coefficient of ischemic regions that experienced HT was significantly lower than the overall mean±SD apparent diffusion coefficient of all ischemic areas analyzed (0.510±0.140ϫ10 −3 mm 2 /s vs 623±0.113ϫ10 −3 mm 2 /s; P=.004). This difference remained significant when comparing the HTdestined ischemic areas with the non-HT-destined areas within the same ischemic lesion (P=.02). Patients receiving recombinant tissue-type plasminogen activator (rt-PA) experienced HT significantly earlier than patients not receiving rt-PA (P=.002). Moreover, a persistent perfusion deficit in the area of subsequent hemorrhage at 3 to 6 hours after the initial MRI scan was identified in significantly more patients who experienced HT than in those who did not (83% vs 30%; P=.03). Conclusion: Both DWI and PWI scans detect abnormalities that are associated with HT. These findings support a role for MRI in identifying patients who are at increased risk for secondary HT following acute ischemic stroke.
JAMA neurology, 2018
It is uncertain whether therapeutic reperfusion with endovascular treatment yields more or less brain edema. To elucidate the association between reperfusion and brain edema. The secondary objectives were to evaluate whether brain edema could partially be responsible for worse outcomes in patients with later reperfusion or lower Alberta Stroke Program Early Computed Tomography Score. This was a post hoc analysis of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN), which was a prospective, randomized, multicenter clinical trial of endovascular treatment compared with conventional care of patients with acute anterior circulation ischemic stroke. Of 502 patients enrolled from December 2010 to June 2014, 2 patients declined to participate. Additionally, exclusion criteria were absence of follow-up imaging or presence of parenchymal hematoma, resulting in 462 patients included in this study. Brain edema was assess...