A Noninvasive Quantification Approach for Monitoring Brain Metabolic Alterations After Surgical Intervention in Ischemic Cerebrovascular Disease

Abstract

Purpose: Non-invasive quantification of cerebral metabolic rate for glucose (CMRGlc) and characterizing cerebral metabolism of cerebrovascular territories are useful for the understanding of ischemic cerebrovascular disease (ICVD). Here, we proposed a non-invasive quantification approach based on image-derived input function (IDIF) suitable for ICVD patients and monitored the pathophysiological changes after surgical intervention.Methods: Sixteen healthy controls and 26 ischemic cerebrovascular disease patients with baseline and after surgical visits underwent 18F-FDG PET/MR imaging. The voxel-wise CMRGlc maps were derived via our proposed IDIF method. The CMRGlc and standardized uptake value ratio (SUVR) maps were subsequently used to extract quantitative values within 7 volumes of interest (gray matter, white matter, anterior, middle, and posterior cerebral artery, basilar artery, and cerebellar artery territory). Intraclass correlation coefficient (ICC) and absolute percentage error were employed to measure consistency in healthy controls. The quantitative differences of healthy controls and patients at baseline and after surgical visits were statistically analyzed. Results: For healthy controls, there were no significant differences for region CMRGlc values across bilateral and unilateral IDIF measurements (ICC: 0.91-0.98). Significant differences in CMRGlc were observed across the cohorts in all territories (P< 0.001). The CMRGlc values in the ipsilateral side were significantly increased after surgery intervention (P < 0.05) for all territories (percentage changes: 7.4%~22.5%). Only the posterior cerebral artery and basilar artery territories (-2.8% and 1.9%) were significant differences for SUVR (P < 0.05). The diagnostic ability of CMRGlc in various territories (area under curve: 0.923-0.966) was significantly higher than of SUVR. There was a significant association between CMRGlc with the national institutes of health stroke scores (r: -0.54, P = 0.0041).Conclusion: These observations suggested the non-invasive quantification approach based on IDIF allowed the individual metabolism measurement of cerebrovascular territories after surgery and identified the glucose pathology changes underlying territories.