¹⁸F-FDG PET/CT images quality and its impact factors in diabetic and non-diabetic patients with coronary artery disease

Objective: To evaluate the image quality (IQ) of ¹⁸F-fluorodeoxyglucose (FDG) PET/CT imaging and identify its influenfial factors in diabetes mellitus (DM) and non-DM patients with coronary artery disease (CAD). Methods: A total of 196 consecutive CAD patients (174 males, 22 females, 68 DM; age: (57 ± 10) years) in Beijing Anzhen Hospital between June 2016 and February 2018 were retrospectively analyzed. All patients underwent ¹⁸F-FDG myocardial PET/CT imaging. The standardized fasting+ oral glucose loading (OGL) and intravenously injection of insulin protocol was performed. According to the FDG uptake by myocardium, background activity in blood and other visceral organ nearby the heart, the IQ was visually evaluated and scored by 0-4. Zero-two was considered as good IQ, 3-4 was regarded as poor IQ. Patients were divided into three groups: group 1 (non-DM+good IQ), group 2 (DM+good IQ), group 3 (DM+poor IQ). Factors which may affect IQ were analyzed, which including OGL, the injection dose of insulin, fasting blood glucose (FBG), peak blood glucose (PBG), blood glucose (BG) level at ¹⁸F-FDG injection (BG_injnection), BG increasing rate ((PBG-FBG)/FBG, %), and BG decreasing rate ((PBG-BG_injection)/PBG, %). One-way analysis of variance, Spearman correlation analysis and logistic regression analysis were used for data analysis. Results: There were significant differences (F values: 13.074-38.371, all P < 0.05) of FBG, PBG, OGL, BG decreasing rate and the injection dose of insulin among group 1 (n = 132, 67.3%), group 2 (n = 53, 27.1%), group 3 (n = 11, 5.6%). All those parameters, except for OGL, were positively correlated with FDG PET/CT IQ (r_s values: 0.142-0.262, all p < 0.05). Ogle was negatively correlated with IQ (r_s = -0.324, P < 0.05). Logistic regression analysis showed that Fag (odds ratio (Or) = 0.687, 95% CI: 0.633-0.746), Pebg (Or = 0.786, 95% CI: 0.746 ∼ 0.829), BG_injection (OR = 0.631, 95% CI: 0.595-0.716), OGL (OR = 0.897, 95% CI: 0.873-0.922), the injection dose of insulin (OR = 0.680, 95% CI: 0.618-0.748) were predictive factors (all P < 0.01) for good IQ in all patients. For DM patients, OGL was the only predictive factor for good IQ (OR = 0.940, 95% CI: 0.904-0.960 P < 0.01). Conclusions: FBG, PBG, BG_injection, OGL, the injection dose of insulin can predict IQ for all patients with CAD. For DM patients with CAD, OGL is the only predictive factor for good IQ. A good IQ of ¹⁸F-FDG PET/CT could be obtained in majority of CAD patients, with the standardized fasting+ OGL and intravenously injection of insulin protocol and adjust according to the personal status, and prevent the hypoglycemia from happening. (authors)