Maximum Lesions Area and Orthogonal Values Accessed from DWI Images Would Be Alternative Imaging Markers for Predicting the Outcome of Acute Ischemia in the Middle Cerebral Artery Territory

Background: Evaluating the acute ischemic volume on diffusion-weighted imaging (DWI) in the middle cerebral artery (MCA) territory would predict outcome.

Purpose: To investigate the correlations between maximum area with restricted diffusion (MaxA), the orthogonal diameters (OD) as well as lesion volume on DWI, and to explore the role of MaxA and OD on predicting unfavorable outcome after an acute MCA ischemic stroke.

Material And Methods: Sixty consecutive adult patients, including modified Rankin Scale score (mRS) ≤2 (n = 31) and mRS > 2 (n = 29) groups, were retrospectively enrolled. The MaxA and OD of lesions were assessed at the slice containing the largest infarction size on DWI images. We compared the prediction efficiencies of these methods on unfavorable outcomes.

Results: The correlation coefficients between the MaxA and infarction volume and OD and infarction volume were 0.982 ( P < 0.001) and 0.952 ( P < 0.001), respectively. The times required for measuring MaxA (150 s [130-160]) and OD (30 s [20-60]) were much shorter than that for infarction volume measurement (1240 s [180-1480]) ( P = 0.001, P = 0.004). With thresholds of ≥57.3 mL for infarction volume, ≥15.2 cm for MaxA, and ≥38.1 for the arithmetic product of OD, the AUCs of infarction volume, MaxA, and OD for predicting an unfavorable outcome were 0.818, 0.821, and 0.820, respectively.

Conclusion: Since they correlated well with the infarction volume, MaxA and OD assessed on DWI were time-saving and achieved comparable diagnostic efficiencies; thus, they may represent alternative imaging markers for predicting unfavorable outcomes of acute ischemic stroke in MCA territory.