1. Student Case Presentation Radiology Elective Period 5 ACR 75.49 FA Kuyateh UVA SOM ‘05

2. A 59 y.o. female with h/o DVT on Coumadin, and lung CA s/p chemotherapy experienced melena for three days before she was found unresponsive and brought to the ER. She was resuscitated, intubated, and admitted to the MICU after she was found to have an INR of 15 and a blood pressure of 40/palp as well as acute renal failure, severe acidosis and hypoxia. During hospitalization she experienced abdominal distention and blood via NG tube and rectum. Labs drawn showed an elevated total bilirubin (2.9 and 1.6 on day 6) and slightly elevated alkaline phosphatase (173 on day 3). Right upper quadrant ultrasounds on HD #6 showed linear echogenic structures within the liver indicating pneumobilia vs. portal venous gas. AXR on HD#6 showed mild gastric distention, gas within non-distended loops of large bowel on upright film, and scattered air-fluid levels on decubitus film.

4. Portal Venous Air..located more peripherally

5. Air tracks in mesentery veins Mesenteric air

6. Pneumatosis Intestinalis of sigmoid colon

7. Radiographic findings: Right upper quadrant ultrasounds showed linear echogenic structures within the liver. AXR showed mild gastric distention and gas within non-distended loops of large bowel on supine film, and scattered air-fluid levels on lateral decubitus film. CT scan revealed evidence of portal venous gas in periphery of left hepatic lobe. There are air tracks within the mesenteric veins. There is interval development of air within the bowel wall failing to rise with the rest of the bowel air = pneumatosis intestinalis.

8. Diagnosis: Sigmoid Ischemia Discussion: Findings of gastric distention, portal air, mesenteric air, and pneumatosis are consistent with bowel infarct. Portal is caused by breakdown of infarcted mucosal barrier and leakage of air and toxins into portal venous system. Portal air is differentiated from biliary air by location in system. Portal venous flow is centrifugal (away) from the hilum and spreads out to the periphery, whereas biliary flow is centripetal to hilum from periphery. Hence portal air is usually seen along the margins of the liver. Pneumatosis and mesenteric air are formed by similar mechanisms. This patient with an INR of 15 sustained a bowel ischemic event possibly due to systemic shock secondary to excessive bleeding.

9. References Halpert R, Feckzo P: GI Radiology, The Requisites. 2 nd Ed. St Louis, MO. 1999. Novelline R. Squire’s Fundamentals of Radiology. 5 th Ed. Cambridge, MA. 1997.