Presentation
Preoperative CT for a hepatic lesion.
Patient Data









Multisepated cystic lesion (6x4.5x4 cm) centered on the segments VIII/V with peripheral calcification (hydatid cyst).
The left renal vein is compressed between the aorta posteriorly and superior mesenteric artery (SMA) anteriorly with dilated pre-compressed vein drained into a dilated hemiazygos vein. Reduced aortic-SMA angle measuring 12° (normal angle around 45°). Collateral pathways are seen at the renal hilum with no dilated left ovarian vein.
The compression ratio (CR) given by the equation: CR=(P-C)/C was equal to 4.5
Case Discussion
CT features of hepatic hydatid cyst with a Nutcracker phenomenon. In the absence of clinical symptoms as in this case, the renal vein compression between the aorta and SMA is called Nutcracker phenomenon which is a more common situation and considered an incidental finding.
Additional contributor: A. Ramdani, MD