Computed tomographic evaluation of the retrocrural prevertebral space

Abstract

Abdominal computed tomography (CT) scans of 151 patients were reviewed for the presence of discrete structures between the vertebra and the diaphragmatic crura. A distinct retrocrural structure larger than 6 mm in diameter was present in 39 patients. In 112 patients the retrocrural space contained discrete structures smaller than 6 mm or showed no definable structures. Of the 39 patients with retrocrural structures larger than 6 mm in diameter, 37 had clinical and other CT evidence as well as biopsy or lymphangiographic evidence of middle to upper abdominal paraaortic adenopathy. Only three of the 112 patients exhibiting retrocrural structures smaller than 6 mm had such evidence of associated retroperitoneal adenopathy. These three were found to have enlarged nodes, but in the lower rather than the middle or upper abdomen. It is concluded that discrete retrocrural structures larger than 6 mm represent enlarged lymph nodes. Smaller retrocrural structures represent azygous veins or normal lymphatic structures.