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Aims: To assess the impact of various patient characteristics on the dynamics of liver glucose metabolism using automated multiparametric imaging with whole‐body dynamic 18F‐fluorodeoxyglucose (FDG)‐positron emission tomography (PET). Materials and Methods: We retrospectively enrolled 540 patients who underwent whole‐body dynamic FDG‐PET. Three quantitative indices representing hepatic glucose metabolism [mean standardized uptake value normalized by lean body mass (SULmean), metabolic glucose rate (kinetic index) and distribution volume (DV)] were measured from multiparametric PET images produced automatically based on the Patlak plot model. Patient characteristics including age, sex, body mass index, fasting time, blood glucose level, and the presence of diabetes mellitus (DM) or hepatic steatosis (HS) were collected. We examined the correlations between the characteristic factors and three quantitative indices using multiple regression analysis. Results: The success rate of kinetic analysis using multiparametric PET imaging was 93.3% (504/540). Hepatic SULmean was significantly correlated with age (p <.001), sex (p <.001) and blood glucose level (p =.002). DV was significantly correlated with age (p =.033), sex (p <.001), body mass index (p =.002), fasting time (p =.043) and the presence of HS (p =.002). The kinetic index was significantly correlated with age (p <.001) and sex (p =.004). In the comparison of the healthy, DM and HS groups, patients with DM had a significantly increased SULmean, whereas patients with HS had a significantly decreased DV. Conclusions: Our results showed that liver glucose metabolism was influenced by various patient characteristic factors. Multiparametric FDG‐PET imaging can be used to analyse the kinetics of liver glucose metabolism in routine clinical practice. [ABSTRACT FROM AUTHOR]

Background: Abdominal aortic aneurysms expand over time and increase the risk of fatal ruptures. To predict expansion, the isolated assessment of 18 F-fluorodeoxyglucose (FDG) and sodium fluoride (NaF) uptake or calcification volume in aneurysms has been investigated with variability in results. We systematically evaluated whether 18 F-FDG and 18 F-NaF uptake was predictive of abdominal aortic aneurysm expansion., Methods: Seventy-four male Sprague-Dawley rat abdominal aortic aneurysm models were imaged using positron emission tomography-computed tomography with 18 F-FDG and 18 F-NaF at 1, 2, 4, 6, and 8 weeks after CaCl 2 or saline stimulation. In the 1-week cohort (n=25), the correlation between 18 F-FDG or 18 F-NaF uptake and pathological markers was investigated. In the time course cohort (n=49), animals received either atorvastatin, losartan, aldactone, or risedronate to assess the effect of these drugs, and the relationship between aortic size and sequential 18 F-FDG and 18 F-NaF uptake or calcification volume was examined., Results: In the 1-week cohort, the maximum standard unit value of 18 F-FDG and 18 F-NaF uptake correlated with CD68- (r=0.82; P =0.001) and von Kossa staining-positive areas (r=0.89; P <0.001), respectively. In the time course cohort, 18 F-FDG and 18 F-NaF uptake changed in a time-dependent manner and drugs attenuated this uptake. Specifically, 18 F-FDG showed high uptake at weeks 1 and 2, whereas a high 18 F-NaF uptake was noted throughout the study period. Atorvastatin and risedronate showed a decreased and increased aortic size, respectively. The final aortic area correlated well with 18 F-FDG and 18 F-NaF uptake and calcification volume, especially at 1 and 2 weeks ( 18 F-NaF [1 week]: r=0.61, 18 F-FDG [2 weeks]: r=0.51, calcification volume [1 week]: r=0.59; P <0.001). Multiple linear regression analysis showed that the combination of these factors predicted the final aortic size, with 18 F-NaF uptake at 1 week being the strongest predictor., Conclusions: The uptake of 18 F-NaF and 18 F-FDG and the calcification volume at appropriate times correlated with the development of abdominal aortic aneurysms, with 18 F-NaF uptake being the strongest predictor., Competing Interests: None.

Aims: To assess the impact of various patient characteristics on the dynamics of liver glucose metabolism using automated multiparametric imaging with whole-body dynamic 18 F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)., Materials and Methods: We retrospectively enrolled 540 patients who underwent whole-body dynamic FDG-PET. Three quantitative indices representing hepatic glucose metabolism [mean standardized uptake value normalized by lean body mass (SULmean), metabolic glucose rate (kinetic index) and distribution volume (DV)] were measured from multiparametric PET images produced automatically based on the Patlak plot model. Patient characteristics including age, sex, body mass index, fasting time, blood glucose level, and the presence of diabetes mellitus (DM) or hepatic steatosis (HS) were collected. We examined the correlations between the characteristic factors and three quantitative indices using multiple regression analysis., Results: The success rate of kinetic analysis using multiparametric PET imaging was 93.3% (504/540). Hepatic SULmean was significantly correlated with age (p < .001), sex (p < .001) and blood glucose level (p = .002). DV was significantly correlated with age (p = .033), sex (p < .001), body mass index (p = .002), fasting time (p = .043) and the presence of HS (p = .002). The kinetic index was significantly correlated with age (p < .001) and sex (p = .004). In the comparison of the healthy, DM and HS groups, patients with DM had a significantly increased SULmean, whereas patients with HS had a significantly decreased DV., Conclusions: Our results showed that liver glucose metabolism was influenced by various patient characteristic factors. Multiparametric FDG-PET imaging can be used to analyse the kinetics of liver glucose metabolism in routine clinical practice., (© 2023 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.)

Background Patients who developed myocarditis following SARS-CoV-2 vaccination show abnormalities on cardiac MRI. However, whether myocardial changes occur in asymptomatic individuals following vaccination is not well established. Purpose To assess myocardial 18 Fluorine-fluorodeoxyglucose ( 18 F-FDG) uptake on PET/CT in asymptomatic SARS-CoV-2 vaccinated patients compared to nonvaccinated patients. Materials and Methods This retrospective study included patients who underwent 18 F-FDG PET/CT for indications unrelated to myocarditis during the period before (11/1/2020 - 2/16/2021) and after (2/17/20121 - 3/31/2022) SARS-CoV-2 vaccines were available. Myocardial and axillary FDG uptake were quantitatively assessed using maximum standardized uptake value (SUVmax). SUVmax values in all patients and in patients stratified by sex (male/female), age (<40, 41-60, >60 years), and time interval between vaccination and PET/CT were compared using Mann-Whitney U test or Kruskal-Wallis test with post ad -hoc Dwass, Steel, Critchlow-Fligner multiple comparison analysis. Results The study included 303 nonvaccinated patients (mean age, 52.9 years ± 14.9 [SD]; 157 females) and 700 vaccinated patients (mean age, 56.8 years ± 13.7 [SD]; 344 females). Vaccinated patients had overall higher myocardial FDG uptake compared to nonvaccinated patients (median SUVmax, 4.8 [IQR: 3.0-8.5] vs median SUVmax, 3.3 [IQR: 2.5-6.2]; P < .0001). Myocardial SUVmax was higher in vaccinated patients regardless of sex (median range, 4.7-4.9 [IQR: 2.9-8.6]) or patient age (median range, 4.7-5.6 [IQR: 2.9-8.6]) compared to corresponding nonvaccinated groups (sex median range, 3.2-3.9 [IQR: 2.4-7.2]; age median range, 3.3-3.3 [IQR: 2.3-6.1]; P range, <.001-.015). Furthermore, increased myocardial FDG uptake was observed in patients imaged 1-30, 31-60, 61-120, and 121-180 days after their second vaccination (median SUVmax range, 4.6-5.1 [IQR: 2.9-8.6]) and increased ipsilateral axillary uptake was observed in patients imaged 1-30, 31-60, 61-120 days after their 2nd vaccination (median SUVmax range, 1.5-2.0 [IQR: 1.2-3.4]) compared to the nonvaccinated patients ( P range, <.001-<.001). Conclusion Compared to nonvaccinated patients, asymptomatic patients who received their 2nd vaccination 1-180 days prior to imaging showed increased myocardial FDG uptake on PET/CT. See also the editorial by Bluemke in this issue.