Diffusion-weighted whole-body imaging with background body signal suppression/T2-weighted image fusion of gastrointestinal cancers.

Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) yields positive results for cancer against the surrounding tissues. The combination of DWIBS and T2-weighted images (DWIBS/T2) in the diagnosis of gastrointestinal tract cancers was retrospectively analyzed in the present study. Patients were subjected to magnetic resonance imaging after cancer was diagnosed through specimens obtained via biopsy or endoscopic mucosal resection. Sixteen patients were assessed between July, 2012 and June, 2013 and the correlation between detection with DWIBS/T2 and T staging was analyzed. Regarding patients who underwent surgery, the correlation between detection with DWIBS/T2 and the diameter or depth of invasion was analyzed. All cancers that had advanced to >T2 stage were detectable by DWIBS/T2, whereas all cancers staged as <T1 were not (P<0.0001). Tumors that were undetected by DWIBS/T2 had a mean diameter of 1.53±0.25 cm, whereas those detected had a mean diameter of 3.63±1.88 cm; however, the difference was not statistically significant (P=0.1053). Cancers invading beyond the muscularis propria were detectable by DWIBS/T2, while those which had not invaded the mucosa were not (P=0.0476). In conclusion, DWIBS/T2 was able to positively identify gastrointestinal tract cancers at an advanced stage (>T2) or invading beyond the muscularis propria.