ABSTRACT
The ultrasonographic findings of urinary obstruction indicate the diagnosis of hydronephorsis. Hydrophrosis is a descriptive term referring to the presence of dilatation of pelvis and calyces and not to the cause of the ddilation IVU can provide functional and anatomical details while ultrasonography can only provide anatomical details There are some different ideas about diagnostic values of each method. The purpose of this study is to evaluate the ultrasonoyraphic sensitivity in detection of hydronephrosis [obstructive or nonobstructive] as compared to IVU. This prospective comparative study was done on 70 patients referring to the radiology department of Bahman 22[nd]and Arya Hospitals since April 2006 to October 2007. Kidney ultrasonography and IVU were administered for all the patients. Then, the accuracy rate of ultrasonography in diagnosing hydronephrosis was determined comparing with IVU as a gold standard method. Some variables such as age, sex, the size of kidney, kidney parenchymal echo, ureteral stone, bladder condition in IVU and stone in KUB were evaluated in all the patients. Among 70 patients, the mean age was 36 +/- 16.3 years ranging from 12 to 72 years. Comparing ultrasonography with IVU, the sensivity of ultrasonography for diagnosing hydronephrosis was 79.41%, the specificity rate of ultrasonography was 55%; the positive predictive value was 62% and the negative predictive value was 74%. Also, the accuracy rate of sonography in diagnosing hydronephrosis was 67%. The results of this study suggest that although ultrasonography is not a substitute for IVU, it can be used as a preliminary tool for detecting hydronephrosis and as a screening diagnostic method for urinary obstruction in azotemic patients. IVU is suggested for acute urinary obstructions and in patients with renal colic and normal sono-findings