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. There is no significant literature supporting the use of CTA abdomen and pelvis with IV contrast only. CTA Abdomen and Pelvis Without and With IV Contrast In traumatic UGIB, it is important to identify the source quickly, safely, and effectively. CT is frequently performed in patients with trauma to assess for visceral injuries. In patients with UGIB, multiphase CTA can effectively and quickly evaluate abdominal vasculature, GIB, and visceral injuries simultaneously. Mesenteric contrast extravasation has a 75% sensitivity for mesenteric injury [69]. CT can help in triage and prognostication, with active bleeding in the arterial or portal venous phase more likely to be life-threatening versus bleeding that first appears in the equilibrium phase [69]. A rare but life-threatening cause of postsurgical or iatrogenic UGIB can be aortoenteric fistula. CTA is the examination of choice [70]. Evidence of a fistula is suggested by gas in a periprosthetic fluid collection, retraction of the contacting intestinal walls, or the presence of a false aneurysm. Extravasation of contrast into the intestinal lumen is diagnostic of aortoenteric fistula but rarely occurs. Even in patients that can undergo endoscopy, CTA is superior and more sensitive compared with endoscopy for the diagnosis of aortoenteric fistula [71]. CTA Abdomen With IV Contrast There is no significant literature supporting the use of CTA abdomen with IV contrast for postsurgical or post- traumatic UGIB. CTA Abdomen Without and With IV Contrast There is no significant literature supporting the use of CTA abdomen without and with IV contrast for postsurgical or post-traumatic UGIB.
Nonvariceal Upper Gastrointestinal Bleeding. 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. There is no significant literature supporting the use of CTA abdomen and pelvis with IV contrast only. CTA Abdomen and Pelvis Without and With IV Contrast In traumatic UGIB, it is important to identify the source quickly, safely, and effectively. CT is frequently performed in patients with trauma to assess for visceral injuries. In patients with UGIB, multiphase CTA can effectively and quickly evaluate abdominal vasculature, GIB, and visceral injuries simultaneously. Mesenteric contrast extravasation has a 75% sensitivity for mesenteric injury [69]. CT can help in triage and prognostication, with active bleeding in the arterial or portal venous phase more likely to be life-threatening versus bleeding that first appears in the equilibrium phase [69]. A rare but life-threatening cause of postsurgical or iatrogenic UGIB can be aortoenteric fistula. CTA is the examination of choice [70]. Evidence of a fistula is suggested by gas in a periprosthetic fluid collection, retraction of the contacting intestinal walls, or the presence of a false aneurysm. Extravasation of contrast into the intestinal lumen is diagnostic of aortoenteric fistula but rarely occurs. Even in patients that can undergo endoscopy, CTA is superior and more sensitive compared with endoscopy for the diagnosis of aortoenteric fistula [71]. CTA Abdomen With IV Contrast There is no significant literature supporting the use of CTA abdomen with IV contrast for postsurgical or post- traumatic UGIB. CTA Abdomen Without and With IV Contrast There is no significant literature supporting the use of CTA abdomen without and with IV contrast for postsurgical or post-traumatic UGIB.