Emphysematous pyelonephritis. Radiologic and clinical findings in six cases.

Six patients (all women, mean age 59.8 years) with emphysematous pyelonephritis, a rare, severe inflammation causing renal parenchymal destruction and affecting diabetics more commonly than non-diabetics, are described. Four of the patients were diabetics. All underwent ultrasound examination (US), and five computed tomography (CT) of the kidneys. CT was the most reliable diagnostic method. Differentiation between gas and calcification was difficult at US in three patients. Conventional tomography was performed in two patients and showed intra-renal gas. All six patients recovered; three patients had nephrectomy, one as an emergency procedure and two as an elective procedure after two weeks of antibiotic treatment. Infection was eradicated in the other three patients by percutaneous drainage, electrolyte correction and antibiotics. It was concluded that while conventional abdominal radiography may permit the diagnosis of emphysematous pyelonephritis by demonstrating intra-renal gas, CT is the most reliable diagnostic examination. Emergency nephrectomy may not be necessary in all cases.