The probability of middle cerebral artery MRA flow signal abnormality with quantified CT ischaemic change: targets for future therapeutic studies

Abstract
Objectives: In this study we define the probability of vascular abnormality in the middle cerebral artery (MCA) territory according to the extent of ischaemic change seen using computed tomography (CT). We assessed the sensitivity and specificity of the hyperdense middle cerebral artery (HMCA) and the “dot” sign using magnetic resonance angiography (MRA). Methods: Patients presenting with ischaemic stroke had a CT scan (Results: A total of 100 consecutive patients had baseline CT and MR scans. The median NIHSS was 9. The median CT ASPECTS was 8 and equalled the median DWI ASPECTS. There were a total of 10 HMCA and 19 MCA “dot” signs, with four patients having both HMCA and “dot” signs. A total of 47 MRA flow signal abnormalities were observed in the anterior circulation. Conclusions: In the absence of accessible neurovascular imaging, the extent of CT ischaemia (ASPECTS) is a strong predictor of vascular occlusion. The CT hyperdense artery signs have a high positive predictive value but low negative predictive value.