The hybrid 18F-FDG PET/MRI can be used to non-invasively diagnose and follow-up the course of IBD such as ulcerative colitis and Crohn’s disease. 

A prospective study was conducted to determine the value of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) in the diagnostics and follow-up of inflammatory bowel disease (IBD) and further, comparatively assess the data procured utilizing PET/MRI to histological findings.

From a gastroenterology outpatient clinic or a hospital ward, 10 individuals suffering from relapse in IBD or with the symptoms of suspected IBD were recruited. Utilizing histology and 18F-FDG PET/MRI, the intestinal inflammation was evaluated.

In six areas of the intestine (rectum, small bowel, ascending colon, transverse colon, descending colon, and sigmoid colon), the maximum standard uptake values (SUVmax) were accurately estimated and compared to the histological assessment of the inflammatory activity.

The PET/MRI illustrated severe inflammatory lesions in the bowel wall as substantially elevated SUVs. Both the the region of the biopsy in the intestine and the inflammation activity were found to have an important impact on SUV.

Compared to the normal bowel wall, moderate inflammation produced elevated SUVs, but the difference was not found to be statistically significant. Mild inflammatory lesions could not be distinguished from normal bowel walls since the SUVs of mild inflammation were found to be at a similar level with SUVs of the normal bowel wall.

Furthermore, the region of biopsy seems to have a vital effect on the SUV. This advocates that the accumulation of 18F-FDG varies in different regions of the bowel even though the inflammation activity is equal.

The mucosal inflammation detected by PET/MRI was found to be substantially correlated with the histologically determined active inflammation. However, more data are needed to elucidate its specificity and sensitivity.

18F-FDG PET/MRI is a potential methodology to detect very severe inflammatory bowel lesions.