{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T11:00:05Z","timestamp":1785495605308,"version":"3.56.0"},"reference-count":30,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T00:00:00Z","timestamp":1785456000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Clin. Med.","JCM"],"abstract":"<jats:p>Background\/Objectives: Extracranial\u2013intracranial (EC-IC) bypass, particularly superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis, is used to augment cerebral perfusion in selected patients with moyamoya disease or atherosclerotic steno-occlusive disease. This study evaluated the impact of STA-MCA bypass on regional cerebral perfusion using a semi-quantitative SPECT area-based method. Methods: Of 40 patients screened between June 2018 and June 2022, 15 with complete paired pre- and postoperative CTA and SPECT data were included. Postoperative imaging was performed at a median of 12 months (range, 6\u201315 months). Proportional perfusion area in the basal ganglia and temporal regions was calculated using Labelme annotation, Canny edge detection, and Green\u2019s theorem, normalized to total brain area. Paired comparisons and exploratory subgroup analyses were performed. Normality was assessed by Shapiro\u2013Wilk test; Wilcoxon signed-rank tests served as sensitivity analyses. Results: Mean age was 56 \u00b1 15.7 years (40% female). All 16 anastomoses were patent. Postoperative perfusion area increased significantly in the basal ganglia (mean difference 0.24, 95% CI 0.13\u20130.35, p = 0.0003) and temporal regions (0.34, 95% CI 0.08\u20130.60, p = 0.012). Wilcoxon tests confirmed these findings (basal ganglia p = 0.0003; temporal p = 0.008). In unilateral cases, ipsilateral and contralateral basal ganglia improvements did not differ significantly (p = 0.839). Results should be interpreted as exploratory given the limited sample size. Conclusions: STA-MCA bypass was associated with significant increases in semi-quantitative perfusion area on SPECT, particularly in the basal ganglia. The lack of ipsilateral\u2013contralateral difference is consistent with a possible global hemodynamic effect, but this interpretation remains hypothesis-generating. The pragmatic SPECT method is feasible for perioperative monitoring yet requires further validation. Larger prospective studies with standardized protocols are warranted.<\/jats:p>","DOI":"10.3390\/jcm15155981","type":"journal-article","created":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T10:11:38Z","timestamp":1785492698000},"page":"5981","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Semi-Quantitative Assessment of Regional Cerebral Blood Flow Changes Following Extracranial\u2013Intracranial Bypass Using SPECT: A Single-Center Retrospective Study"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0008-2854-2780","authenticated-orcid":false,"given":"Ying-Chia","family":"Wu","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, Neurological Institute, Taichung Veterans General Hospital, Taichung 40705, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yen-Chih","family":"Fong","sequence":"additional","affiliation":[{"name":"Department of Management Information Systems, National Chung Hsing University, Taichung 40227, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2420-9178","authenticated-orcid":false,"given":"Meng-Hsiun","family":"Tsai","sequence":"additional","affiliation":[{"name":"Department of Management Information Systems, National Chung Hsing University, Taichung 40227, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuang-Seng","family":"Tsuei","sequence":"additional","affiliation":[{"name":"College of Medicine, National Chung Hsing University, Taichung 40227, Taiwan"},{"name":"Department of Surgical Medicine, Chung Shan Medical University, Taichung 40201, Taiwan"},{"name":"Department of Neurosurgery, Taichung Veterans General Hospital, Taichung 40705, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2544-0400","authenticated-orcid":false,"given":"Chung-Hsin","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Taichung Veterans General Hospital, Taichung 40705, Taiwan"},{"name":"Institute of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,31]]},"reference":[{"key":"ref_1","first-page":"553","article-title":"Efficacy of superficial temporal artery-middle cerebral artery bypass in patients with cerebrovascular steno-occlusive diseases","volume":"60","author":"Kwon","year":"2017","journal-title":"J. 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