Differential Vessel features according to the Pathophysiologic Type of Intracranial Atherosclerosis

BACKGROUNDPrevious studies have assessed the relationship between vessel tortuosity and atherosclerosis in long vessel segments. We evaluated the relationship between tortuosity and parent artery atherosclerotic disease (PAD) in short vessel segments, and the differences between the PAD and branch atheromatous disease (BAD). METHODSComputerized analysis of the images provided quantitative vessel features at every 0.2841 mm interval point of the vessels centerline. The vessel features that reflect vessel tortuosity include curvature and torsion. To analyze the local features of the vessels, the middle cerebral artery (MCA) was divided into three segments. RESULTSA total of 59 and 77 patients with PAD and BAD of the MCA were included. Stenotic segments were isolated in 33 patients with PAD and were mostly located in the distal segment; stenotic segments were also isolated in 24 patients with BAD and were mostly located in the middle segment (P=0.074). The curvature of the stenotic segment of PAD was significantly increased compared to the non-stenotic segments of the ipsilateral (0.29 {+/-} 0.08 for the stenotic segment vs. 0.26 {+/-} 0.07 for the non-stenotic segment, P=0.048), and increased but not significant compared to the stenotic segment of BAD (0.29 {+/-} 0.08 for PAD vs. 0.26 {+/-} 0.05 for BAD, P=0.083). In the multivariable regression analysis, curvature (odds ratio, 2.136; 95% confidence interval, 1.251-3.645; P=0.005) was associated with PAD. CONCLUSIONSOur findings suggested that increased tortuosity is associated with the development of PAD and that PAD and BAD have different vessel features and plaque locations and thereby, different pathophysiological mechanisms.