Noninvasive assessment of pediatric inflammatory bowel disease with ¹⁸F-fluorodeoxyglucose-positron emission tomography and computed tomography.

OBJECTIVES: ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) is a less invasive diagnostic tool and promising in detecting gastrointestinal lesions of pediatric inflammatory bowel disease (IBD) patients. Co-registration of low-dose computed tomography (CT) could lead to improvements in the assessment of disease. Therefore, this retrospective study evaluates the value of PET±CT in pediatric IBD patients. PATIENTS AND METHODS: We analyzed ¹⁸F-FDG-PET scans without (n=24) or with combined (n=21) low-dose CT in children (18 females, 27 males, age: 3.7-16.7 years, median 13.2 years) who presented with the diagnosis of IBD (n=45). Results of PET±CT scans and conventional diagnostic procedures (endoscopy, histology, and ultrasound) were compared by a segment-based analysis.
RESULTS: Overall, 253 segments of the gastrointestinal tract (GIT) were explored by endoscopy/histology and ¹⁸F-FDG-PET±CT. Twenty-five additional small bowel segments were assessed by abdominal ultrasound and further 152 GIT segments not reached during endoscopy were evaluated by PET±CT. PET±CT revealed a segment-based sensitivity, specificity, positive predictive value, negative predictive value, and an accuracy for the detection of GIT lesions of 82, 97, 96, 88, and 91%, respectively. The patient-based sensitivity and specificity was 97 and 100%, respectively. Interestingly, the co-registration of CT did not improve the diagnostic informative value.
CONCLUSION: FDG-PET±CT is especially suitable for the assessment of IBD in children. The radiation exposure of 3-7 mSv is justified by the accuracy of this approach. FDG-PET seems to be a reliable tool for detecting inflamed gut segments in IBD with high sensitivity and specificity. The co-registration of CT had no additional benefit.