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

In 1956 the present authors compared urography with inulin and P A H (para-aminohippuric acid) clearances of individual kidneys as a test of renal function in a series of normal cases and cases of renal disease. This further communication deals with the correlation of the urographie findings with the clearance and urinary concentration tests in a series of cases of hyperparathyroidism. Material and M e t h o d sThe material consisted of 20 cases of hyperparathyroidism in which the blood calcium, initially elevated, reverted to normal levels after parathyroidectomy. Two of these had a single functioning kidney, one having had nephrectomy for calculi, and the other showing evidence of non-function of one kidney by urography and clearance tests.A total of 43 urographies were performed, 10 before and 33 after parathyroidectomy. In 38 the contrast material was 40 ml Urografin (sodium 4-methyl-

In a previous paper (1960) the present authors reported on the relation of urography to inulin and PAH (para-aminohippuric acid) clearance and concentration tests performed in a series of cases of hyperparathyroidism. This paper reports a study on the relations of roentgen-anatomic changes in the kidneys, including size and the presence of calcifications, to the functional tests in the same material.Material and Methods. The present series comprises 29 cases of hyperparathyroidism in which the blood calcium, initially elevated, reverted to normal after parathyroidectomy. Two of the patients were subjected to nephrectomy for concretions.Routine roentgenograms of the kidneys were taken before and after the operation in 28 cases, and in one case only postoperatively. In many cases control examinations were performed before and after operation. As to the size of the kidneys in routine films, a length of 10 to 15 em and a width of 5 to 8 em are regarded as normal.A total of 38 urographies in 18 of the patients are reported, all performed