PSEUDO-PNEUMORETROPERITONEUM SECONDARY TO LUMBAR EMPHYSEMA - CT DEMONSTRATION IN 2 CASES

Several conditions may simulate the radiolucent appearances of pneumor etroperitoneum at plain film. These include gas shadows in locations o ther than the retroperitoneal space or fluid within the retroperitonea l compartments. Two cases of emphysema within the soft tissues of the back mimicking pneumoretroperitoneum on plain radiographs are describe d. One case was secondary to epidural anesthesia and another to trauma . In both, computed tomography (CT) led to the correct diagnosis. The possible pitfalls in the differential diagnosis of retroperitoneal gas are described with emphasis of the diagnostic role of CT.