The Added Prognostic Value of Intracranial Artery Morphology to Predict Non-Cardioembolic Ischemic Stroke

Abstract

Purpose: To assess the added prognostic value of the morphologic characteristics of intracranial arteries in the risk modeling of a future non-cardioembolic stroke. Materials and Methods: This retrospective study included 86 patients without acute ischemic stroke who first underwent magnetic resonance imaging (MRI) including the time-of-flight magnetic resonance angiography (TOF-MRA) at 3T. Diffusion- weighted imaging (DWI) was performed for the follow-up imaging of these patients > 120 days after the initial MRI. The TOF-MRA result was used to analyze three morphological characteristics: dilatation, stenosis, and tortuosity. The presence of acute ischemic stroke was assessed using the follow-up DWI data. We built two prognostic models: model 1 includes the conventional stroke-risk factors, while model 2 includes the conventional risk factors and the morphologic characteristics of the intracranial arteries. We used the likelihood-ratio test to compare these two models. The models’ performances were evaluated using Harrell’s concordance index. Results: Fourteen patients suffered non-cardioembolic strokes. The performances of the two models differed significantly regarding the future-risk modeling of the noncardioembolic stroke (p = 0.031). The Harrell’s concordance index of model 2 (0.78 ± 0.05) exceeded that of model 1 (0.72 ± 0.07). Conclusion: In addition to the conventional stroke-risk factors, the morphologic characteristics of the intracranial arteries were useful in the modeling of the future risk of the non-cardioembolic ischemic stroke.

Keywords

• cerebral arteries
• morphology
• mri angiography
• brain infarction
• intracranial arteriosclerosis