Renal papillary necrosis, called also necrosis of the renal papillae, necrotizing papillitis, and papillitis necroticans, is an uncommon condition, usually found in diabetic patients, although it may occur in non-diabetics. It has been recognized pathologically for many years, having been first described by von Friedreich in 1877 (1). Since that time 181 cases have been recorded, of which only 10 per cent failed to show evidence of diabetes, obstructive uropathy, or both (2). Because this disease is not well known, usually being discovered unexpectedly at necropsy, it is felt worthwhile to report a single case diagnosed radiographically during life. To our knowledge there has been no previous report of this type in the radiological literature. Olsson (3) in 1939 presented a case diagnosed by a gas pyelogram obtained as a result of fermentation of sugar in the urine of a diabetic. In 1945 Eskelund (4) published a case of necrotizing papillitis of the kidney following retrograde pyelography in a fifty-five-...