Differential Vessel features according to the Pathophysiologic Type of Intracranial Atherosclerosis

BACKGROUND Previous 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). METHODS Computerized analysis of the images provided quantitative vessel features at every 0.2841 mm interval point of the vessel’s 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. RESULTS A 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. CONCLUSIONS Our 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. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was supported by the National Research Foundation of Korea and funded by the Ministry of Science and ICT (NRF-2020M3E5D2A01084891; Dr Seo and NRF-2020M3E5D2A01084892; Dr. Park). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Institutional Review Board of SMC approved the study design (SMC-2021-04-072). This study was conducted in accordance with the principles of the Declaration of Helsinki. Informed consent was waived by the SMC Institutional Review Board for the control group because the study progressed in a retrospective manner, and we provided the clinical data and brain images in an anonymized form. Written informed consent was obtained from all the patients enrolled in the SMC stroke registry. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data presented in this study are available on request from the corresponding authors. The data are not publicly available due to privacy.