Methods: The radiological charts of all 284 patients that had undergone a DMSA scintigraphy between January 2009 and February 2012 have been reviewed. Correlation between ultrasound and DMSA scans results for the search of renal scars was the main focus. Two hundred fifty (250) patients and 467 renal units have been included after exclusion of patients with difference higher than a year between the ultrasound and nuclear studies or anatomical features that invalidate one of the studies.
Results: Of the 467 renal units evaluated, 46 (9,9%) presented scarring on ultrasound examination and 118 (25,3%) on DMSA scintigraphy (ultrasound sensibility (se) 29,7%, specificity (sp) 96,9%). Thirty-five (35) of the 46 (76%) kidneys with a scar on ultrasound examination had scarring confirmed on the nuclear exam. The results are similar when we compare ultrasound evaluations performed with newer to older machines (older: se 31,6%, sp 96.8%; newer : se 21,7%, sp 97%). When considering only the ultrasound and DMSA scans evaluations done in the same week, the results remain in the same range. Globally, if result are analyzed by patient for more clinical significance, of the 250 patients, 41 (16%) demonstrated scarring on ultrasound compared to 99 (39,6%) on scintigraphy.
Conclusion: In our center, the actual use of the ultrasound data is not powerful enough to give reliable information about renal scarring, even with more sensitive instruments. Even with its inconvenient, DMSA scintigraphy is still mandatory in the evaluation of renal scars to help in our clinical decision making.