Cerebral Blood Volume ASPECTS Is the Best Predictor of Clinical Outcome in Acute Ischemic Stroke: A Retrospective, Combined Semi-Quantitative and Quantitative Assessment

Abstract

IntroductionThe capability of CT perfusion (CTP) Alberta Stroke Program Early CT Score (ASPECTS) to predict outcome and identify ischemia severity in acute ischemic stroke (AIS) patients is still questioned.Methods62 patients with AIS were imaged within 8 hours of symptom onset by non-contrast CT, CT angiography and CTP scans at admission and 24 hours. CTP ASPECTS was calculated on the affected hemisphere using cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) maps by subtracting 1 point for any abnormalities visually detected or measured within multiple cortical circular regions of interest according to previously established thresholds. MTT-CBV ASPECTS was considered as CTP ASPECTS mismatch. Hemorrhagic transformation (HT), recanalization status and reperfusion grade at 24 hours, final infarct volume at 7 days and modified Rankin scale (mRS) at 3 months after onset were recorded.ResultsSemi-quantitative and quantitative CTP ASPECTS were highly correlated (p<0.00001). CBF, CBV and MTT ASPECTS were higher in patients with no HT and mRS≤2 and inversely associated with final infarct volume and mRS (p values: from p<0.05 to p<0.00001). CTP ASPECTS mismatch was slightly associated with radiological and clinical outcomes (p values: from p<0.05 to p<0.02) only if evaluated quantitatively. A CBV ASPECTS of 9 was the optimal semi-quantitative value for predicting outcome.ConclusionsOur findings suggest that visual inspection of CTP ASPECTS recognizes infarct and ischemic absolute values. Semi-quantitative CBV ASPECTS, but not CTP ASPECTS mismatch, represents a strong prognostic indicator, implying that core extent is the main determinant of outcome, irrespective of penumbra size.

CBV_ASPECTS Improvement over CT_ASPECTS on Determining Irreversible Ischemic Lesion Decreases over Time

“…Sixty-five patients (25 men), with a mean age of 67 ± 14 years (range 36-86) were studied. Median National Institutes of Health Stroke Scale (NIHSS) at onset was [16][17][18][19][20].…”

“…In this study, we explored the advantages of CBV_ASPECTS over CT_ASPECTS in the prediction of final infarct volume, as a surrogate marker of clinical outcomes [20,21] . Previous studies have shown a higher prognostic value of CTV_ASPECTS compared to CT_ASPECTS [14,16,17,22] and this is confirmed by our data.…”

Contribution of Neuro-Imaging for Prediction of Functional Recovery after Ischemic Stroke

“…For multimodal MRI, addition of both DWI and MTT lesion volumes to NIHSS information is superior to NIHSS alone in predicting outcomes [83,84]. In one study, it was found that the cerebral blood volume defined by CTP ASPECTS was the best predictor of clinical outcome in acute ischemic stroke as it recognizes the infarct; it was better than CTP mismatch implying that the extent of the core is the main determinant of outcome, irrespective of the penumbra site [85]. CBV-ASPECTS was also a significant predictor of clinical outcome in patients with acute ischemic stroke treated with mechanical thrombectomy [86].…”

Capabilities of perfusion ASPECTS in predicting the efficiency of intravenous thrombolytic therapy

“…При этом лишь величина ядра инфаркта и сумма ранних признаков ишемии явились предикторами неврологическо-го дефицита при выписке, что согласуется с результатами исследования M. Padroni и соавт. [12]. В то же время в отли-чие от результатов указанного исследования, в котором так-же показана четкая ассоциация CBV ASPECTS, но не CBV -MTT ASPECTS, c результатом МШР через 3 мес, в нашей работе именно увеличение размеров пенумбры явилось пре-диктором функциональных ограничений по МШР.…”

“…Использованы следующие перфузионные пороги: rCBV≤40%, rCBF<40% и rMTT>145% [11]. Так как MTT и CBV отражают зоны общей гипоперфузии и ядра инфаркта соответственно, ASPECTS mismatch рассчитывали как CBV ASPECTS минус MTT ASPECTS (CBV -MTT ASPECTS) [12]. Зона ядра инфаркта также идентифицировалась по со-четанию rCBF<40% и rMTT>145% (CBF + MTT ASPECTS) [11].…”