CT is often the initial examination for patients with clinical findings of proctitis or pouchitis because of its ability to evaluate inflammatory thickening of the rectal or pouch wall, associated abscess, possible fistula, or anastomotic leak in an IPAA. IV contrast-enhanced CT is preferred over a noncontrast CT because the presence of IV contrast will allow detection of abnormal enhancement of the bowel wall as well as the presence of rim-enhancement that would suggest abscess in any associated fluid collection. To our knowledge, there are no studies in the literature using modern CT technology that evaluate the accuracy of routine pelvic CT with or without IV contrast for the diagnosis of proctitis or pouchitis. FDG-PET/CT Skull Base to Mid-Thigh Fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT has been reported to be a useful tool in assessing the degree of inflammatory activity in patients with ulcerative colitis and CD [49,50]. Shyn et al [51] compared FDG- PET/CT enterography to conventional CT enterography in evaluating patients with CD. In this study, FDG-PET/CT enterography showed sites of active inflammation in 3 of 13 cases (23.1%) that were not seen on CT enterography, though these areas were not in the rectum or a surgical pouch. To our knowledge, there is no relevant recent literature regarding the use of FDG-PET/CT in the evaluation of suspected proctitis or pouchitis. Fluoroscopy Contrast Enema Fluoroscopic contrast enemas performed for the diagnosis of perforation or leak, rectovaginal or rectovesicular fistula, pouchitis, or proctitis can be performed with water-soluble contrast or barium. In general, water-soluble contrast is preferred if a leak or perforation is suspected in order to avoid barium spillage into the peritoneal cavity or extraperitoneal pelvis. Using barium may also interfere with a subsequent CT scan because of the streak artifact that it causes on CT.
Anorectal Disease. CT is often the initial examination for patients with clinical findings of proctitis or pouchitis because of its ability to evaluate inflammatory thickening of the rectal or pouch wall, associated abscess, possible fistula, or anastomotic leak in an IPAA. IV contrast-enhanced CT is preferred over a noncontrast CT because the presence of IV contrast will allow detection of abnormal enhancement of the bowel wall as well as the presence of rim-enhancement that would suggest abscess in any associated fluid collection. To our knowledge, there are no studies in the literature using modern CT technology that evaluate the accuracy of routine pelvic CT with or without IV contrast for the diagnosis of proctitis or pouchitis. FDG-PET/CT Skull Base to Mid-Thigh Fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT has been reported to be a useful tool in assessing the degree of inflammatory activity in patients with ulcerative colitis and CD [49,50]. Shyn et al [51] compared FDG- PET/CT enterography to conventional CT enterography in evaluating patients with CD. In this study, FDG-PET/CT enterography showed sites of active inflammation in 3 of 13 cases (23.1%) that were not seen on CT enterography, though these areas were not in the rectum or a surgical pouch. To our knowledge, there is no relevant recent literature regarding the use of FDG-PET/CT in the evaluation of suspected proctitis or pouchitis. Fluoroscopy Contrast Enema Fluoroscopic contrast enemas performed for the diagnosis of perforation or leak, rectovaginal or rectovesicular fistula, pouchitis, or proctitis can be performed with water-soluble contrast or barium. In general, water-soluble contrast is preferred if a leak or perforation is suspected in order to avoid barium spillage into the peritoneal cavity or extraperitoneal pelvis. Using barium may also interfere with a subsequent CT scan because of the streak artifact that it causes on CT.