Purpose: While CT/MR enteroclysis provides excellent anatomical details, it fails to provide information on metabolic activity of the inflammatory lesions of the intestine. We conceptualized a fusion of metabolic imaging techniques such as PET and an anatomical imaging modality such as CT enteroclysis to derive information both on morphological details and functional activity of lesions at the same time.
Patients and methods: In a prospective study, we included 17 adult patients with newly diagnosed inflammatory diseases of the intestine. Low dose whole body PET-CT scan was obtained first, which began at approximately 60 min after injection of 10 mCi of (18)fluoro-deoxyglucose (FDG). Subsequently, PET-CT enteroclysis of the abdomen was performed after infusion of 2 l of 0.5% methylcellulose through a naso-jejunal catheter.
Results: Fourteen patients had abnormal and three had normal PET-CT enteroclysis studies. Twenty-three segments of small intestine and 27 segments of large intestine showed increased FDG uptake. The detection rate of PET-CT enteroclysis was significantly higher (total =50 segments, 23 segments of small intestine and 27 segments of large intestine) as compared with barium studies (16 segments of small intestine) and colonoscopy (17 segments of large intestine) combined together (total =33 segments). In addition PET-CT enteroclysis showed extra-luminal FDG uptake (lymph nodes in two, sacroilitis in two, and mesenteric fat proliferation in five).
Conclusions: As a single investigation, PET-CT enteroclysis detects a significantly higher number of lesions both in the small and large intestine in comparison to that detected by conventional barium and colonoscopy combined together. This technique is non-invasive, feasible and very promising.