[ comparison of two different diuretic renal Scintigraphy protocols in patients with dilated upper urinary tract]

ABSTRACT

Diuretic renal scan is preferred noninvasive investigation in evaluating upper urinary tract function and assessing upper tract dilatation or obstruction. There are several protocols for diuretic renal scan which are named according to timing of diuretic administration before, after or at the same time of radiopharmaceutical injection. Timing of diuretic administration is not universally standardized in renography. In the present study we compared F-15, F+20 diuretic renography protocols in patient with upper urinary tract dilatation. From Feb 2004 to Nov 2005, 21 patients were referred with flank pain and pyelocalyceal system dilatation without ureteral dilatation in ultrasonography and after history taking, physical exams and radiological studies such as IVP, retrograde pyelogram, serum creatinin measurement and urine analysis, F-15 and F+20 diuretic renal scans were performed. The pharmaceutical drug in this study was TC-EC [Ethylene dicysteine]. Renal function data, curves and renograms were recorded and patients were undergone conservative or surgical therapy and followed up with physical exams and IVP or diuretic renal scan after 3-6 months and then we compared results with two diuretic renal scan protocols. We used marginal homogeneity test to compare renograms and paired t-student tests to compare renal function in two protocols. Among 21 cases, 15 were male and 6 were female. Mean age was 16.3 +/- 25 years. Left pyelocalyceal system dilatation was reported in 15 cases and right side dilation was seen in 6 cases. Chief complain of patients was flank pain. Ultrasound showed pyelocalyceal dilatation without uretral dilatation. IVP findings included delayed pyelogram and pyelocalyceal dilatation without seeing the ureter. Of all renal diuretic scans, 52.2 percent of patients had obstruction pattern in F-15 and F+20 protocols. Results were equivocal in 23.3% of F+20 scans whereas they had complete obstructive pattern in F-15 scans.14% had normal pattern in F+20 and F-15 scans. 9.5% had nonobstructive pattern in F+20 but equivocal or obstructive pattern in F-15 scans. Obstructions were diagnosed in 52.2% of patient by F+20 scan and in 75.5% by F-15 scan. Renal split function didn't change in F-15 and F+20 diuretic renogram protocols. According to the equivocal results of F+20 diuretic renal scans, F-15 can reduce equivocal results of F+20 diuretic renal scans. Of course we recommend future investigations to approve or disapprove this hypothesis: