Assessment of middle cerebral artery atherosclerotic stenosis using 7T high-resolution MRI and time-of-flight MRA: A comparative analysis with DSA

Abstract

Background

Ischemic stroke, often caused by intracranial atherosclerotic stenosis (ICAS), is a leading cause of disability and death globally. 7T MRI offers improved signal-to-noise ratio (SNR) and contrast, enhancing MRA image quality. This study assessed the accuracy of 7T high-resolution (HR) MRI and time-of-flight MRA (TOF-MRA) in measuring middle cerebral artery (MCA) stenosis compared to digital subtraction angiography (DSA).

Methods

In this prospective observational study, patients, diagnosed with MCA atherosclerotic stenosis, underwent 7T HR-MRI, TOF-MRA and DSA. Spearman correlation analysis was used to assess the linear correlation between HR-MRI, TOF-MRA, and DSA measurements of MCA stenosis. Agreement for stenosis classification data was evaluated using weighted kappa values. Receiver Operating Characteristic (ROC) curves were utilized to predict severe stenosis and occlusion of MCA in HR-MRI and TOF-MRA.

Results

This study included 86 lesions from 81 patients with MCA atherosclerotic stenosis. The stenosis degree measurements between 7T HR-MRI and DSA indicated a very strong correlation (r = 0.8000; p < .0001). The correlation between 7T TOF-MRA and DSA assessments was high (r = 0.7188; p < .001). A robust correlation between 7T HR-MRI and TOF-MRA evaluations was shown (r = 0.839; p < .0001). 7T TOF-MRA (K = 0.673) demonstrated substantial agreement with DSA measurements, showing slight superiority over HR-MRI (K = 0.589). ROC analysis indicated both 7T HR-MRI and TOF-MRA effectively predicted severe MCA stenosis and occlusion (HR-MRI, AUC: 0.888; TOF-MRA, AUC: 0.878).

Conclusions

7T HR-MRI and TOF-MRA may emerge as comparable modalities for assessing MCA atherosclerotic stenosis, and HR-MRI allows for precise evaluation through direct visualization of the vessel lumen and plaque.