However, a study showed a higher sensitivity of CT enterography (88%) for the diagnosis of etiology of occult GIB, significantly higher than capsule endoscopy (sensitivity 38%) in their study population [54]. Advantages of CT enterography over capsule endoscopy are ease of performance and better patient satisfaction [5]. CTA Abdomen and Pelvis With IV Contrast In endoscopy-negative patients, there is no significant literature for CT abdomen and pelvis with IV contrast for GIB evaluation. Dual-energy CT allows for the generation of virtual noncontrast images from a CTA data set. However, the use of these virtual unenhanced images in place of true unenhanced images is still limited to certain sites and remains a user-specific preference. So, they are not discussed in this document. CTA Abdomen and Pelvis Without and With IV Contrast Both CTA and CT enterography are effective imaging tests for the diagnosis of UGIB with negative endoscopy. Studies have demonstrated that there is no significant clinical difference between accuracy of CTA and enterography for endoscopy-negative GIB [55,56]. CTA can detect bleeding rates as slow as 0.3 mL/min [19]. But, as with angiography, intermittent and slow bleeding can be missed, leading to false-negatives. The sensitivity of CTA has been shown to be 81% in high-risk patients (ie, patients requiring 500 mL of transfusion to maintain vital signs), which decreases to 50% in patients with a slow bleed [57]. The portal venous or delayed phase of multiphasic CT may be more useful for detection of GI masses. CTA and CT enterography can serve as triage tools for identifying patients who may benefit from double-balloon endoscopy [58]. CTA Abdomen With IV Contrast In endoscopy-negative patients, there is no significant literature for CTA abdomen with IV contrast for GIB evaluation.
Nonvariceal Upper Gastrointestinal Bleeding. However, a study showed a higher sensitivity of CT enterography (88%) for the diagnosis of etiology of occult GIB, significantly higher than capsule endoscopy (sensitivity 38%) in their study population [54]. Advantages of CT enterography over capsule endoscopy are ease of performance and better patient satisfaction [5]. CTA Abdomen and Pelvis With IV Contrast In endoscopy-negative patients, there is no significant literature for CT abdomen and pelvis with IV contrast for GIB evaluation. Dual-energy CT allows for the generation of virtual noncontrast images from a CTA data set. However, the use of these virtual unenhanced images in place of true unenhanced images is still limited to certain sites and remains a user-specific preference. So, they are not discussed in this document. CTA Abdomen and Pelvis Without and With IV Contrast Both CTA and CT enterography are effective imaging tests for the diagnosis of UGIB with negative endoscopy. Studies have demonstrated that there is no significant clinical difference between accuracy of CTA and enterography for endoscopy-negative GIB [55,56]. CTA can detect bleeding rates as slow as 0.3 mL/min [19]. But, as with angiography, intermittent and slow bleeding can be missed, leading to false-negatives. The sensitivity of CTA has been shown to be 81% in high-risk patients (ie, patients requiring 500 mL of transfusion to maintain vital signs), which decreases to 50% in patients with a slow bleed [57]. The portal venous or delayed phase of multiphasic CT may be more useful for detection of GI masses. CTA and CT enterography can serve as triage tools for identifying patients who may benefit from double-balloon endoscopy [58]. CTA Abdomen With IV Contrast In endoscopy-negative patients, there is no significant literature for CTA abdomen with IV contrast for GIB evaluation.