Additionally, oral contrast use in a known or suspected high-grade SBO does not add to diagnostic accuracy and can delay diagnosis, increase patient discomfort, and increase the risk of complications, particularly vomiting and aspiration. The use of positive oral contrast agents can also potentially limit the ability to detect abnormal bowel wall enhancement in the case of ischemia and hypoperfusion. However, SBO may be identified in patients who have undergone CT with oral (with or without IV) contrast (ie, when SBO was not specifically suspected at the time the study was ordered/protocolled). Multidetector CT scanners with multiplanar reconstruction capabilities have been noticeably more effective for evaluating SBO and other abdominal pathology [21-26]. Multiplanar reformations have also been found to increase accuracy and confidence in locating the transition zone in SBO, which can be a useful adjunct if an operative intervention is planned [24,27,28]. CT with IV contrast is preferable for routine imaging of suspected SBO, in part to demonstrate whether the bowel is perfusing normally or is potentially ischemic, and in a minority of cases, to provide information about the potential etiology, such as Crohn disease and neoplasm. Noncontrast CT appears to have comparable accuracy for diagnosing or excluding high-grade SBO, although determination for ischemia is reduced [29]. CT Enteroclysis In the clinical setting of acute pain and distention, the use of CT enteroclysis is not favorable, because patients cannot tolerate the active infusion of oral contrast into an obstructed small-bowel. CT enteroclysis is generally favored over conventional enteroclysis because it avoids the problem of overlapping small-bowel loops, and it has been shown to demonstrate a larger number of bowel abnormalities and more abnormalities outside the bowel [61].
Suspected Small Bowel Obstruction. Additionally, oral contrast use in a known or suspected high-grade SBO does not add to diagnostic accuracy and can delay diagnosis, increase patient discomfort, and increase the risk of complications, particularly vomiting and aspiration. The use of positive oral contrast agents can also potentially limit the ability to detect abnormal bowel wall enhancement in the case of ischemia and hypoperfusion. However, SBO may be identified in patients who have undergone CT with oral (with or without IV) contrast (ie, when SBO was not specifically suspected at the time the study was ordered/protocolled). Multidetector CT scanners with multiplanar reconstruction capabilities have been noticeably more effective for evaluating SBO and other abdominal pathology [21-26]. Multiplanar reformations have also been found to increase accuracy and confidence in locating the transition zone in SBO, which can be a useful adjunct if an operative intervention is planned [24,27,28]. CT with IV contrast is preferable for routine imaging of suspected SBO, in part to demonstrate whether the bowel is perfusing normally or is potentially ischemic, and in a minority of cases, to provide information about the potential etiology, such as Crohn disease and neoplasm. Noncontrast CT appears to have comparable accuracy for diagnosing or excluding high-grade SBO, although determination for ischemia is reduced [29]. CT Enteroclysis In the clinical setting of acute pain and distention, the use of CT enteroclysis is not favorable, because patients cannot tolerate the active infusion of oral contrast into an obstructed small-bowel. CT enteroclysis is generally favored over conventional enteroclysis because it avoids the problem of overlapping small-bowel loops, and it has been shown to demonstrate a larger number of bowel abnormalities and more abnormalities outside the bowel [61].