No. 364 Celiac artery compression syndrome: review of causes and appearances R. Florek, E.K. Lang, Dr, D. Beary, R. Tanenbaum, D. Casey, J. Gomez; Radiology, Lourdes Regional Medical Center, Lafayette, LA; Radiology, West Jefferson Medical Center, Marrero, LA; Radiology, SUNY Downstate Medical Center, New York, NY; Radiology, North Oaks Medical Center, Hammond, LA; Radiology, Tulane Univ. Medical Center, New Orleans, LA Purpose: To review the causes of celiac artery compression syndrome (CACS) with diagnostic CT angio appearance. Materials and Methods: Symptomatic and asymptomatic cases of celiac artery compression are reviewed to demonstrate the cause and extent of celiac narrowing and/or encasement. Recruitment of collateral flow channels can render CACS asymptomatic (1), depending on the amount of the collaterization, usually by the gastroduodenal artery (GDA) arcade, less commonly via the arcade of Roland, or from the left gastric artery. Results: Computed tomography angiography (CTA) of celiac artery compression syndrome can demonstrate a variety of causes: athersclerosis being the most common; followed by median arcuate ligament syndrome (MALS); mass effect by tumor, aneurism, or lymph nodes, and rarely by retroperitoneal fibrosis (RPF). Treatment options vary, depending on the cause; stenting is used for athersclerotic narrowing of the proximal lumen, surgical release of the median arcuate ligament is usually done laparoscopically (2), and tumor debulking can be done either surgically or by radiotherapy. Doppler ultrasound can be used to document the increase in flow after stenting or surgical release (3). RPF remains problematic as retroperitoneal encasement affect multiple organs. Conclusion: 1. CACS remains a clinical diagnosis, with flow deficits ranging from asymptomatic to debilitating, depending on development of collateral flow pathways. 2. CTA diagnosis of CACS is the most accurate way to demonstrate the etiology of CACS, visualizing both intraluminal and extrinsic causes, as well as collateralization of flow to the liver and proximal small bowel.