SNMMI 2026
PET reveals whole-body metabolic reset after bariatric surgery
Clinical Takeaway: In patients with obesity, bariatric surgery appears to trigger coordinated metabolic remodeling across adipose tissue, liver, pancreas, muscle, cardiovascular, immune, and endocrine organs. Whole-body FDG-PET/CT may provide insights into recovery that aren’t captured by body weight or routine laboratory tests alone.
Bariatric surgery is known to improve obesity-related comorbidities, but clinicians have had limited tools to visualize how metabolic recovery unfolds across the body. Whole-body PET/CT may offer a new way to monitor organ-level responses and guide personalized follow-up care.
A retrospective study presented at SNMMI 2026 evaluated 32 adults with obesity who underwent laparoscopic sleeve gastrectomy or one-anastomosis gastric bypass. Participants received whole-body 18F-FDG PET/CT imaging and comprehensive laboratory testing before surgery and again 12 months later.
Investigators measured FDG uptake in subcutaneous and visceral adipose tissue, liver, pancreas, spleen, adrenal glands, and skeletal muscle, and compared findings with those from healthy controls. The imaging analysis revealed coordinated metabolic and structural changes across multiple organ systems after surgery, including adipose tissue, liver, pancreas, skeletal muscle, cardiovascular structures, bone-related tissues, and immune-endocrine organs.
Changes in organ metabolism and organ volume were significantly associated with improvements in glycemic, lipid, endocrine, and inflammatory biomarkers. Network analyses also demonstrated stronger inter-organ metabolic connections after surgery, suggesting that metabolic activity across the body became more synchronized during recovery.
Representative PET/CT images showed marked reductions in subcutaneous and visceral fat depots as well as decreases in liver, pancreatic, splenic, and skeletal muscle volumes one year after surgery.
“Metabolic recovery after bariatric surgery is a whole-body process,” said presenting author Zeyang Wang, MSc. “Molecular imaging may help show how different organs respond after surgery, beyond what can be measured by weight loss or blood tests alone.”
The findings suggest that whole-body FDG-PET/CT could emerge as a valuable tool for mapping organ-level metabolic health and monitoring recovery following bariatric surgery.
Source: Wang Z, et al. Evaluation of organic metabolic profiling alteration assessed by [18F]FDG PET/CT in obese patients before and after bariatric surgery. Presented at: Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting; May 2026; Los Angeles, CA. Abstract 261206.