Acute Lower GI Bleed due to a Bleeding

Diverticulum in the Right Colon

Submitted by Flavius F. Guglielmo, MD

Thomas Jefferson University Hospital, Philadelphia, PA

SAR GI Bleeding DFP

Clinical History:

69 yo female on blood thinners, presenting with bright red blood

per rectum and abdominal cramping. The patient was

hemodynamically stable although there was a 3 gram drop in the

hemoglobin level.

CT Angiography of the abdomen and pelvis was performed.

GI Bleeding

GI Bleeding Early Arterial Phase

Precontrast Early Arterial Phase Portal Venous Phase

69 yo female on blood thinners, presenting with bright red blood per rectum and abdominal cramping. CT Angiography of the abdomen and pelvis was performed. 1. What is the location and likely cause of the acute lower GI bleed? 2. What is the most common cause of acute lower GI bleeding? 3. Should positive enteric contrast be administered for CTA when protocoling acute

GI bleeding cases?

Questions

1. Acute extravasation in the right colon due to a bleeding diverticulum. 2. Colonic diverticulosis. 3. Positive enteric contrast will obscure the findings on both noncontrast and post

contrast images and therefore should not be administered when protocoling a CTA for acute GI Bleed.

Answers

GI Bleeding

Noncontrast Early Arterial Phase Portal Venous Phase

Early Arterial Phase

On noncontrast images, there is hyperdense debris consistent with blood in the dependent portion of the right colon. There is colonic diverticulosis.

On early arterial phase images, there is focal enhancement in the right colon consistent with active contrast extravasation in the region where there was blood on noncontrast images.

On portal venous phase images, the active contrast extravasation in the right colon changes in shape, is increased in size and lower in density compared to the early arterial phase.

Teaching Points: Noncontrast images are useful to evaluate for blood in the bowel lumen. The density of the intraluminal hemorrhage may be the highest in the region of active bleeding. Noncontrast images are also useful to determine if a hyperdense focus in the bowel on post contrast images is abnormal enhancement rather than hyperdense intraluminal debris. On postcontrast images, active extravasation will commonly change in shape and density on the second post contrast phase compared to the first phase.

GI Bleeding

References

1. Wells ML, Hansel SL, Bruining DH, Fletcher JG, Froemming AT,

Barlow JM, et al. CT for evaluation of acute gastrointestinal bleeding.

RadioGraphics 2018; 38:1089–1107.

2. Soto JA, Park SH, Fletcher JG, Fidler JL. Gastrointestinal hemorrhage:

evaluation with MDCT. Abdominal Imaging 2015;40(5):993-1009.

3. Kim G, Soto J, Morrison T. Radiologic Assessment of Gastrointestinal

Bleeding. Gastroenterol Clin N Am 47 (2018) 501–514.

GI Bleeding