Comparison of Urography with Selective Clearance as Tests of Renal Function

Abstract

The urographic signs of normal renal function following dehydration of the patient usually consist of simultaneous filling of the calyces on both sides, moderate distension and high density of the pelves and upper parts of the ureters upon application of ureteral compression, and bilateral emptying of the pelves and ureters after the compression is removed. If the examination provokes shock with a decrease in the systolic blood pressure to 70 mm Hg, contrast filling of the pelves does not commence, or ceases, and a nephrographic effect, due to accumulation of contrast medium, and of the same degree in both sides, appears. Following the raising of the blood pressure, excretion into the pelves proceeds.These signs are usually easy to define in the films. More difficult is the situation in hydronephrosis where one or both pelves are dilated, in diabetes with diuresis, or in old people in whom the normal density of the pelves is less than in the middle-aged and young. Another disturbance to a normally functioning kidney is the delayed filling of the pelvis with contrast medium and its accumulation in the renal parenchyma due to an increase in the intrapelvic pressure in acute obstruction to the emptying of the pelvis. In addition there are all the cases with locally or diffusely damaged tissue. In the case of local changes, it may be difficult to determine whether the contrast filling of the di~eased part of the pelvis is primary or secondary; and in the pres-Read at the

Renal Papillary Necrosis: Roentgenologic Diagnosis and Formation of Calculi

“…In one of the cases, for instance, satisfactory urograms were obtained where a clearance examination showed that both the filtration and tubular excretion were reduced by 70 per cent. According to studies by EDLING and co-workers (9), this may be ascribed to the fact that the urographie examination is a qualitative test of func tion. In spite of marked local destruction, the residual functional paren-EENAL PAPILLARY NECROSIS 265 chyma may still, to judge from the films, provide a high urine concentra tion, although this is in fact not the case.…”

“…At the next urographie control a year later all the papillae of the right kidney had been detached, but there was no change in the clinical picture. Where nephrectomy is to be performed it is evidently impossible to exclude papillary changes in the other kidney solely from the roentgenograms; selective clearance tests should also be performed (9). On the other hand, typical necrosis in both the medullary and papillary forms developed during the period of observation in 4 cases, and the papillae were detached without the so-called 'typical' signs appearing -even long afterwards -the clinical picture being just one of ordinary noncomplicated pyelitis or pyelonephritis.…”

Renal papillary necrosis

“…At the next urographic control a year later all the papillae of the right kidney had been detached, but there was no change in the clinical picture. Where nephrectomy is to be performed it is evidently impossible to exclude papillary changes in the other kidney solely from the roentgenograms; selective clearance tests should also be performed (9). On the other hand, typical necrosis in both the medullary and papillary forms developed during the period of observation in 4 cases, and the papillae were detached without the so-called 'typical' signs appearingeven long afterwardsthe clinical picture being just one of ordinary noncomplicated pyelitis or pyelonephritis.…”

Correlation of Urography and Tests of Renal Function

“…The analytic methods of clearance determination were described by EDVALL (1958). Samples of urine were obtained by bladder catheterization.…”