EXPRESS: Hemodynamic Analysis of Lenticulostriate Artery Dilation in MCA Atherosclerotic Stenosis

OBJECTIVE: To investigate the perfusion changes associated with lenticulostriate artery (LSA) dilation in patients with middle cerebral artery (MCA) atherosclerosis utilizing 7.0T MRI and CT perfusion imaging (CTP). METHODS: Forty-eight symptomatic atherosclerotic MCA plaques were analyzed. All patients underwent 7.0T MRI and CTP examinations. LSA dilation was defined as a markedly enlarged vessel diameter comparable to that of MCA M3/M4 segments. The stenotic MCAs were divided into LSA dilation group (n=21) and non-dilation group (n=27). Plaque characteristics, LSA morphological features, and perfusion parameters in the LSA territory were assessed. RESULTS: Compared with the non-dilation group, the LSA dilation group showed significantly higher cerebral blood flow/relative cerebral blood flow (CBF/rCBF) and cerebral blood volume (CBV), and a markedly prolonged mean transit time (MTT) in the LSA-supplied regions (all p < 0.05). The incidence of infarction, superior-wall plaque, and plaque involving the LSA origin was significantly higher in the LSA dilation group than in the non-dilation group (all p < 0.05). CONCLUSION: LSA dilation may indicate a compensatory vascular remodeling process, closely associated with plaque location. This phenomenon is accompanied by distinct hemodynamic alterations within its blood supply territory.