Hyman et al [60] reported that CT was superior to fluoroscopic contrast enema at detecting leaks, with a PPV of 89.5% for CT and 40% for contrast enema in 33 patients who developed leaks. Kaur et al [61] showed a 91% sensitivity, 100% specificity, 100% PPV, and 95% NPV for CT in detecting postoperative anastomotic leaks in a retrospective study 170 patients who had undergone a low anterior resection, emphasizing the importance of rectal contrast material to improve confidence in diagnosis. CT Pelvis CT pelvis may be preferred over CT abdomen and pelvis in specific clinical scenarios when the pelvis alone is the area of clinical concern. To our knowledge there are no studies comparing noncontrast CT with IV contrast- enhanced CT for the detection of postoperative complications. However, IV contrast does improve the detection of abscesses and is important for the evaluation of the integrity of the bowel wall when ischemia or anastomotic dehiscence is suspected. CT with and without IV contrast would only be useful when there is benefit from dual- phase imaging. When anastomotic leak is suspected, rectally administered contrast material is important to demonstrate extraluminal extravasation of contrast to confirm the leak, adding an additional finding to other findings of leak: perianastomotic gas, fluid collection, and staple line integrity. Hyman et al [60] reported that CT was superior to fluoroscopic contrast enema at detecting leaks, with a PPV of 89.5% for CT and 40% for contrast enema in 33 patients who developed leaks. Kaur et al [61] showed a 91% sensitivity, 100% specificity, 100% PPV, and 95% NPV for CT in detecting postoperative anastomotic leaks in a retrospective study of 170 patients who had undergone a low anterior resection, emphasizing the importance of rectal contrast material to improve confidence in diagnosis.
Anorectal Disease. Hyman et al [60] reported that CT was superior to fluoroscopic contrast enema at detecting leaks, with a PPV of 89.5% for CT and 40% for contrast enema in 33 patients who developed leaks. Kaur et al [61] showed a 91% sensitivity, 100% specificity, 100% PPV, and 95% NPV for CT in detecting postoperative anastomotic leaks in a retrospective study 170 patients who had undergone a low anterior resection, emphasizing the importance of rectal contrast material to improve confidence in diagnosis. CT Pelvis CT pelvis may be preferred over CT abdomen and pelvis in specific clinical scenarios when the pelvis alone is the area of clinical concern. To our knowledge there are no studies comparing noncontrast CT with IV contrast- enhanced CT for the detection of postoperative complications. However, IV contrast does improve the detection of abscesses and is important for the evaluation of the integrity of the bowel wall when ischemia or anastomotic dehiscence is suspected. CT with and without IV contrast would only be useful when there is benefit from dual- phase imaging. When anastomotic leak is suspected, rectally administered contrast material is important to demonstrate extraluminal extravasation of contrast to confirm the leak, adding an additional finding to other findings of leak: perianastomotic gas, fluid collection, and staple line integrity. Hyman et al [60] reported that CT was superior to fluoroscopic contrast enema at detecting leaks, with a PPV of 89.5% for CT and 40% for contrast enema in 33 patients who developed leaks. Kaur et al [61] showed a 91% sensitivity, 100% specificity, 100% PPV, and 95% NPV for CT in detecting postoperative anastomotic leaks in a retrospective study of 170 patients who had undergone a low anterior resection, emphasizing the importance of rectal contrast material to improve confidence in diagnosis.