Comparison of the correlation between cerebral [18F]FDG metabolism as assessed by two asymmetry indices and clinical neurological score in patients with ischemic cerebrovascular disease

Purpose To identify a method of assessing cerebral 2-deoxy-2-[ ¹⁸ F]fluoro-D-glucose ([ ¹⁸ F]FDG) metabolism with an asymmetry index (AI) that reflects clinical neurological function in patients with ischemic cerebrovascular disease (ICVD), and to explore its applications and potential value to the ICVD in clinical settings. Procedures: Seventy patients diagnosed with subacute and chronic ischemic stroke were retrospectively analyzed. All patients underwent [ ¹⁸ F]FDG PET/MR scans and were assessed using the National Institutes of Health Stroke Scale (NIHSS) and the Modified Rankin Scale (mRS). Following a year of rehabilitation training, nineteen patients underwent a repeat [ ¹⁸ F]FDG PET/MR scan. The decreased cerebral [ ¹⁸ F]FDG metabolism region was defined as the AI value greater than 10%. Two voxel-wise AIs, designated as AI ₁ and AI ₂ , were calculated based on the standardized uptake value ratio (SUVR). The decreased metabolism on affected side accessed by different AI calculation methods were compared. The correlations between the decreased metabolism and the clinical scores were analyzed. Results The volume and percentage of decreased [ ¹⁸ F]FDG metabolism assessed by AI ₂ was larger than that obtained from AI ₁ (all p  < 0.0001). The correlation coefficients between the clinical scores and the decreased metabolism in temporal and parietal lobes assessed by AI ₁ method were all higher than those from AI ₂ . In addition, the improved follow-up patients showed more pronounced metabolic improvement as assessed by AI ₁ . Conclusions The assessment of cerebral [ ¹⁸ F]FDG metabolism in patients with unilateral internal carotid/middle cerebral artery steno-occlusion to reflect clinical neurological function using the AI ₁ method demonstrated superior performance in comparison to the AI ₂ method.