[Effect of diabetes mellitus on 18F-FDG PET-CT myocardial metabolism image quality in patients with coronary artery disease].

Objective: To analyze the effect of combined diabetes mellitus (DM) on the image quality of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET-CT myocardial metabolism imaging in patients with coronary artery disease (CAD). Methods: A cross-sectional study was conducted. Patients with CAD who underwent myocardial viability assessment in the Department of Nuclear Medicine at Wuhan Union Hospital from December 2018 to June 2023 were retrospectively enrolled as study subjects. Prior to radiotracer injection, oral glucose and intravenous insulin were used to regulate blood glucose levels. Corridor 4DM software was utilized to review images. Image quality and semi-quantitative myocardial ¹⁸F-FDG uptake indices were analyzed. The image quality (IQ) was evaluated through visual assessment, which was rated on a scale from 0 to 4 points. And patients were divided into the good IQ group (0-2 points) and the poor IQ group (3-4 points). On fused PET-CT images, regions of interest were respectively delineated in the left ventricle, the blood pool and the right posterior lobe of the liver, and the semi-quantitative indices of myocardial ¹⁸F-FDG uptake were calculated, including the maximum standardized uptake value (SUV_max) and the mean standardized uptake value (SUV_mean) of the left ventricle, the myocardium-to-blood pool ratio (MBR) and the myocardium-to-liver ratio (MLR). Multivariate logistic regression model to analyze the factors affecting IQ. Results: A total of 135 CAD patients were enrolled, including 116 males and 19 females, aged (56±11) years. The ¹⁸F-FDG uptake indices of myocardium (SUV_max, SUV_mean, MBR, MLR) in the good IQ group were significantly higher than those in the poor IQ group, all P<0.001. And patients in good IQ group showed lower blood glucose levels during the oral glucose loading and intravenously injection of insulin protocol (all P<0.0.05). The combination of DM (OR=3.295, 95%CI: 1.109-9.792, P=0.032) and fasting blood glucose (OR=1.265, 95%CI: 1.018-1.572, P=0.034) were related factors affecting the quality of myocardial metabolic imaging. Conclusions: The combination of DM significantly affect myocardial glucose uptake in CAD patients, resulting in poor image quality. It is crucial to prepare well before PET imaging and to actively manage blood sugar individually for patients with DM in clinical.