A RECENT prospective study suggests that [18F]-FDG PET-MRE may be a valuable tool for assessing treatment response in small bowel Crohn’s disease, offering a potential advancement in disease monitoring beyond traditional diagnostics.
Improving Small Bowel Crohn’s Disease Monitoring
Small bowel involvement in Crohn’s disease (CD) poses ongoing diagnostic and monitoring challenges due to limited accessibility via conventional endoscopy. This study evaluated the role of [18F]-FDG positron emission tomography magnetic resonance enterography (PET-MRE) in tracking treatment efficacy. While PET-MRE has been previously explored for diagnosis, its utility in monitoring inflammation over time had not been established. Researchers hypothesised that inflammation in small bowel segments, quantified via maximum standardized uptake values (SUVMax), would decrease with standard therapy.
PET-MRE Detects Early Treatment Response in CD
The study enrolled 35 patients with suspected small bowel CD, all undergoing baseline ileocolonoscopy, laboratory tests, and PET-MRE, followed by capsule endoscopy for diagnostic confirmation. Treatment decisions were made independently of PET-MRE results. Eighteen patients returned for follow-up PET-MRE after three months of therapy. Results showed a significant decline in median SUVMax from 3.2 to 2.1 (p=0.0025), correlating with improvements in MRE-based inflammation scoring (sMARIA, p=0.001) and reduced faecal calprotectin levels (451 µg/g to 163 µg/g, p=0.004). These findings support PET-MRE’s sensitivity in detecting objective response to treatment.
PET-MRE May Enhance Precision in CD Care
This study highlights the potential of PET-MRE to complement existing diagnostic tools by offering a functional imaging modality capable of tracking disease activity in deep small bowel segments. While the sample size was limited, and longer-term outcomes remain to be studied, the significant reductions in SUVMax and inflammatory biomarkers suggest PET-MRE could enhance personalized treatment strategies and reduce reliance on invasive procedures.
Conclusion
PET-MRE may represent a promising tool for non-invasive, objective monitoring of therapeutic response in small bowel Crohn’s disease, warranting further validation in larger cohorts.
Reference
Mattila J et al. Combined [18F]-FDG PET-MR imaging for monitoring small bowel crohn’s disease. Eur J Nucl Med Mol Imaging. 2025;DOI: 10.1007/s00259-025-07524-4.
