Computed tomography in the evaluation of the solitary or unilateral nonfunctioning kidney.

Computed tomography (CT) using the EMI CT5000/5005 scanner was performed on 14 patients with a solitary functioning kidney demonstrated by other radiological investigations. Examinations before and after intravenous injection of contrast material have been undertaken. In the majority of cases, the patients were referred as a "nonfunctioning kidney" following excretion urography. Other referrals included previous nephrectomy or solitary kidneys. In all cases, the CT scan made possible the definitive diagnosis. The diagnosis included unsuspected hydronephrosis, vestigial kidney, contracted kidney secondary to chronic pyelonephritis and calculus, recurrence of a hypernephroma, and lymphomatous infiltration. Valuable information was obtained about the vascular pedicle, the renal collecting systems, the perinephric space, and the retroperitoneal space including the paraaortic lymph nodes. Furthermore, the increased sensitivity of the technique in detecting lower concentrations of iodine provided information regarding renal function. It is concluded that the noninvasive nature of CT makes it a valuable adjunct in the further investigation of such patients.