Retroperitoneal processes involving the psoas demonstrated by computed tomography.

Twenty-five patients were found to have retroperitoneal pathology involving the psoas muscle including nine patients with inflammatory lesions, three with hematomas, seven with adenopathy, one patient with leukemic infiltration of the psoas, and five with retroperitoneal tumors. Computed tomography (CT) offers a unique method to investigate pathological processes that affect the psoas. In addition, the abdominal films on 24 of the patients were analyzed to correlate the value of radiography with that of CT. Computed tomography confirms the belief that the mere presence of a retroperitoneal mass will not necessarily obliterate the psoas.