Prediction of recurrence in patients with non-acute atherosclerotic middle cerebral artery occlusion: A longitudinal study using computed tomography perfusion and magnetic resonance imaging

Objective This study aimed to assess the performance of time to maximum concentration (Tmax) using computed tomography perfusion for predicting stroke recurrence in patients with symptomatic non-acute atherosclerotic middle cerebral artery occlusion. Methods This retrospective monocentric study enrolled 138 patients diagnosed with non-acute atherosclerotic middle cerebral artery occlusion. In addition to conventional computed tomography angiography or digital subtraction angiography, all patients underwent head computed tomography perfusion and magnetic resonance imaging 7–14 days after stroke and repeat head magnetic resonance imaging at 3–6 weeks. Volume of time to maximum concentration >4 s was considered the hypoperfusion area. The association between imaging characteristics, new ischemic lesion or lesion size increase on magnetic resonance imaging, and patient prognosis was assessed. Results Increased number/area of infarct lesion was observed in 52/138 (37.7%) patients on diffusion weighted imaging 3–6 weeks after the first stroke. The volume of time to maximum concentration >4 s at baseline was strongly associated with infarct lesion development (odds ratio = 1.22 per 10-mL increase, 95% confidence interval: 1.10–1.34, p < 0.001). Volume of time to maximum concentration >4 s exhibited high discriminative ability for poor prognosis (area under the curve = 0.84, 95% confidence interval: 0.78–0.91, p < 0.001) with volume of time to maximum concentration >4 s larger than 99.8 mL being an optimal cutoff (odds ratio = 14.31, 95% confidence interval: 5.84–40.89, p < 0.001, sensitivity = 0.88 and specificity = 0.65). Conclusions The risk of stroke recurrence in patients with symptomatic non-acute atherosclerotic middle cerebral artery occlusion gradually increases with the volume of time to maximum concentration >4 s. Patients with volume of time to maximum concentration >4 s larger than 99.8 mL may have a significantly higher risk of stroke. Volume of time to maximum concentration >4 s on computed tomography perfusion can be used to predict the prognosis in patients with symptomatic non-acute atherosclerotic middle cerebral artery occlusion.