High resolution magnetic resonance imaging features of proximal portion of middle cerebral artery in patients with moyamoya angiopathy

Abstract

Objective To observe the high-resolution magnetic resonance imaging (HR-MRI) features of proximal portion of middle cerebral artery (M1 portion) in patients with moyamoya angiopathy (MMA). Methods Forty-six MMA patients and 12 health volunteers, collected in our hospital from January 2014 to September 2015, were chosen in our study; these subjects were performed three dimensional time of flight magnetic resonance angiography (3D-TOF-MRA) and HR-MRI. The quantitative measurements were conducted retrospectively at the minimum cross-sectional area of vessel and maximum thickness of wall; the morphological changes of the vessel wall of the M1 portion and enhancement or not of wall were evaluated. Moreover, general clinical data and vascular risk factors of all patients were evaluated. Results The minimum cross-sectional area of volunteers was (13.71 ± 2.510) mm2, and the maximum thickness was (0.631±0.203) mm; the minimum cross-sectional area of patients with MMA was (2.700±1.511) mm2, remodeling index was (0.209±0.136), and the maximum thickness was (1.078±0.375) mm. Eccentric thickening was noted in 30.4% patients (14/46), concentric thickening in 69.6% patients (32/46). Wall non-enhancement was noted in 45.7% patients (21/46) and wall enhancement in 54.3% patients (25/46). Eccentric thickening patients had significantly elder age, higher maximum thickness of wall and carotid atherosclerosis rate than concentric thickening patients (P<0.05). Multivariate Logistic regression showed that carotid atherosclerosis were independently associated with wall eccentric thickening (OR=4.986, 95% CI: 1.263-36.046, P=0.026). Wall enhancement patients had significantly higher maximum thickness of wall and hypertension level than the wall non-enhancement patients (P<0.05). Logistic regression showed that hypertension was independently associated with wall enhancement (OR=11.764, 95% CI: 2.081-66.51, P=0.005). Hypertension and carotid atherosclerosis were positively related to the wall thickness (r=0.401, P= 0.008; r=0.415, P=0.004). The maximum thickness was significantly higher in hypertension group than that in normal blood pressure group ([1.234 ± 0.4329] mm vs. [0.936 ± 0.2455] mm, P=0.008). Conclusions M1 portion commonly shows concentric thickening, or eccentric thickening when MMA comorbid with atherosclerosis and negative remodeling in MMA patients on HR-MRI. Wall enhancement is associated with wall thickening, and hypertension is an important factor in the wall thickening. Key words: Moyamoya angiopathy; Proximal portion of middle cerebral artery; High-resolution magnetic resonance imaging