Comparison of high-resolution MRI with CT angiography and digital subtraction angiography for the evaluation of middle cerebral artery atherosclerotic steno-occlusive disease

Intracranial atherosclerotic disease is increasingly recognized as a major stroke subtype worldwide. Current diagnostic evaluation of atherosclerotic disease of the middle cerebral artery (MCA) relies on detection of stenoses with luminographic imaging studies that do not directly visualize plaque unlike high-resolution MRI. This retrospective study seeks to evaluate the accuracy of high-resolution MRI vessel wall imaging, computed tomographic angiography (CTA) and digital subtraction angiography (DSA) in measuring the degree of stenosis within the MCA. 28 recently symptomatic patients with MCA territory symptoms underwent preliminary imaging with CTA followed by high-resolution MRI at 3-Tesla and definitive imaging with DSA for detection of M1 territory steno-occlusive lesions. Measurements of MCA segments on MRI and CTA were compared with reference to DSA values. Sensitivity and specificity of high-resolution MRI vessel wall imaging, CTA using maximum intensity projection (MIP) and CTA using volume rendering (VR) for the detection of stenosis > 50 % and occlusion were 80.0 and 53.6 %, 72.2 and 72.7 %, and 77.8 and 18.2 %, respectively. MRI-derived values correlated better with DSA (Spearman R = 0.68, p < 0.01) than CTA MIP and VR (Spearman R = 0.45, 0.22; p = 0.02, 0.24, respectively). High-resolution MRI of the MCA is capable of accurately measuring the degree of stenosis and is more sensitive than CTA in a sample of high-risk, symptomatic patients. This study, combined with previous reports, supports the potential of morphological MRI to measure intracranial atherosclerotic plaque non-invasively.