Assessment of middle cerebral artery atherosclerotic stenosis using 7T high-resolution MRI and time-of-flight MRA: A
Danyang Fan1, Jiafei Chen2, Fei Chen1
1Department of Neurology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China.
Abstract:
BackgroundIschemic 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).MethodsIn 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.ResultsThis 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).Conclusions7T 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.
Insights
7T high-resolution MRI and time-of-flight MRA show high accuracy in measuring middle cerebral artery stenosis, comparable to digital subtraction angiography, aiding in stroke assessment.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Ischemic stroke, a leading cause of death and disability, is frequently caused by intracranial atherosclerotic stenosis (ICAS).
- 7 Tesla (7T) MRI offers enhanced signal-to-noise ratio and contrast, improving Magnetic Resonance Angiography (MRA) image quality for ICAS assessment.
Purpose of the Study:
- To evaluate the accuracy of 7T high-resolution (HR) MRI and 7T time-of-flight MRA (TOF-MRA) in quantifying middle cerebral artery (MCA) stenosis.
- To compare the performance of these 7T MRI techniques against digital subtraction angiography (DSA), the current gold standard.
Main Methods:
- Prospective observational study involving 81 patients with MCA atherosclerotic stenosis.
- Measurements of MCA stenosis degree using 7T HR-MRI, 7T TOF-MRA, and DSA.
- Statistical analysis included Spearman correlation, weighted kappa for agreement, and Receiver Operating Characteristic (ROC) curves to predict severe stenosis and occlusion.
Main Results:
- Strong correlation between 7T HR-MRI and DSA (r=0.8000, p < .0001) and between 7T TOF-MRA and DSA (r=0.7188, p < .001).
- Both 7T HR-MRI (K=0.589) and 7T TOF-MRA (K=0.673) showed substantial agreement with DSA for stenosis classification, with TOF-MRA demonstrating slightly better agreement.
- ROC analysis confirmed both modalities effectively predicted severe MCA stenosis and occlusion (AUCs > 0.878).
Conclusions:
- 7T HR-MRI and 7T TOF-MRA are accurate and comparable imaging modalities for assessing MCA atherosclerotic stenosis.
- 7T HR-MRI provides precise evaluation by directly visualizing the vessel lumen and plaque, complementing TOF-MRA's capabilities.
