How accurate is ultrasonography in detecting hydronephrosis in azotemic patients?

Abstract

Screening for hydronephrosis continues to be an essential part of the evaluation of patients with azotemia of unknown cause. To determine whether sonography is as reliable as nephrotomography for screening purposes, we carried out a prospective, comparative study. Sixty-two patients were evaluated. Mean serum creatinine was 4.3 mg/dl. Of 116 kidneys, 45 were obstructed according to urographic criteria and 42 of these were correctly called hydronephrotic by sonography. The 3 false negative sonographic studies occurred in 2 patients. All 3 kidneys contained radiopaque calculi visible on the plain abdominal film. Of the 71 nonobstructed kidneys, 5 were mistakenly called hydronephrotic by ultrasound, giving a false positive rate of 7%. We believe it is appropriate to use gray-scale ultrasound as a screening test for urinary obstruction in azotemic patients providing the plain abdominal radiograph shows no calcifications.

Ultrasonography in the diagnosis of renal obstruction.

“…[16][17][18][19][20][21][22] Even minor degrees of dilatation may be detected. To achieve high sensitivity the scanning technique must be painstaking and the images carefully interpreted.…”

Calculus in 16-Year-Old Cadaveric Kidney Transplant: A Unique Case and Literature Review

“…However, these have failed in our case and we suspect that the same has occurred to others who used steroids in similar cases (table 1). Despite a high sensitivity rate, false-negative rates as high as 7% were recorded in diaghnosing hydronephrosis by U/S [8][9][10]. Similarly, a renogram depends on flow for diagnosing obstruction [7,11].…”

Accuracy of Ultrasonography Compared with Urography in Detection of Intrarenal Dilatation in Children

“…The high accuracy does not apply to single sonograms in examination of possible obstruction of unknown origin where some alternative method should be added. Ultrasonography (US) is a method of high accuracy for demonstration of upper urinary tract dilatation both in adults (4,15,17,18) and children (6,7,10,20). The characteristic sonographic appearance of severe and moderate intrarenal dilatation-hydronephrosis has been well described (1,15,16,19,20).…”

“…The characteristic sonographic appearance of severe and moderate intrarenal dilatation-hydronephrosis has been well described (1,15,16,19,20). Slight intrarenal dilatation may also be shown by US but the interpretation of its discrete changes is less clear (2,4,(16)(17)(18). Increased knowledge of the pelvocalyceal echo complex and of physiologic variations has modified the concept of its normal and pathologic appearance (2,8,11,(14)(15)(16) which is affected by the continuous technical progress of US equipment and the improvement of the imaging quality.…”

“…Increased knowledge of the pelvocalyceal echo complex and of physiologic variations has modified the concept of its normal and pathologic appearance (2,8,11,(14)(15)(16) which is affected by the continuous technical progress of US equipment and the improvement of the imaging quality. Even if the accuracy of US in detection of urinary postrenal obstruction has been evaluated and discussed in some reports (2,4,17,18) there is consequently need for further comparative studies (17).…”