P206 Combined positron emission tomography and magnetic resonance imaging in the diagnostics of inflammatory bowel disease: a preliminary report
J. Koffert*1, J. Koffert2, J. Virtanen3, S. Kauhanen2, J. Kemppainen1, J. Sundström4, M. Kallajoki4, M. Voutilainen5
1Turku University Hospital, Turku PET Centre, Turku, Finland, 2Turku University Hospital, Department of Surgery, Turku, Finland, 3Turku University Hospital, Department of Radiology, Turku, Finland, 4Turku University Hospital, Department of Pathology, Turku, Finland, 5Turku University Hospital, Department of Gastroenterology, Turku, Finland
Use of endoscopy and histology is the cornerstone for the diagnosis of inflammatory bowel disease (IBD). The combined positron emission tomography and magnetic resonance imaging (PET-MRI) using fluorodeoxyglucose (18F-FDG) is a promising novel hybrid imaging method. Magnetic resonance imaging (MRI) provides morphological data of the gastrointestinal tract, whereas positron emission tomography (PET) detects metabolic activity related to (eg, inflammation). The aim of our study is to evaluate the value of 18F-FDG PET-MRI in the diagnostics of chronic IBD.
Ileocolonoscopy was performed in patients with suspected or earlier diagnosed IBD. Biopsy specimens were obtained from rectum, colon, and ileum. After endoscopy, sequential PET-MRI with 18 F-glucose was performed, and 3T MRI was conducted with a dedicated contrast-enhanced protocol, and magnetic resonance (MR) enterography to optimise the assessment of both the small bowel and colon. Standard uptake values (SUV) were calculated from PET in 5 regions of intestine (small bowel, ascending, transverse, descending, and rectosigmoid colon).
The study population consisted of 6 patients. Amongst them 2 of 3 patients with active colonic inflammation also had inflammatory activity detected by PET-MRI, whereas 1 patient with mild colitis had normal PET-MRI. All 3 patients with normal ileal and colonic findings at colonoscopy (1 with proctitis) also had normal PET-MRI (Table 1).
|Patient||Endoscopy||Histology||MRI Large bowel||MRI small bowel||PET large bowel||PET small bowel||SUVmax|
|F 39 yr||Proctitis CU||Proctitis||N||N||N||N||3.1 rectum|
|F 19 yr||Pancolitis CU||Colitis, moderate activity||Y||N||Y||N||6.7 descending colon|
|M 25 yr||Colitis from caecum to sigmoid colon Crohn’s d||Active inflammation||Y||N||Y||N||7.2 descending colon|
|F 38 yr||Pancolitis CU||Mild inflammatory activity||N||N||N||N||2.3 Ascending colon|
|M 27 yr||Normal||Normal||N||N||N||N||3.9 ileum|
|F 29 yr||Norma||Normal||N||N||N||N||2.6 ileum|
Figure 1. Coronal PET image shows inflammatory activity of the colon in the patient (F 19 yr) suffering from histologically proved pancolitis (moderate activity). The pathological FDG uptake of colon is most prominent in descending colon.
Figure 2. PET/MRI image of the patient. A thin coronal-oblique MRI slice evaluated as 3D.
PET-MRI is a promising option in the diagnostics of IBD, but more research data are needed to determine its diagnostic accuracy.