New quantitative parameters for evaluating radionuclide cystography and their value in understanding the physiology of reflux.

UNLABELLED: In this descriptive study of radionuclide cystography, time-activity curves were generated from renal pelves with reflux and evaluated to reveal the physiology of the reflux. The generated new parameters were also evaluated for any correlation with the frequency of urinary tract infections and renal scarring.

METHODS

Thirty-two children with reflux to the renal pelvis (36 refluxing units) were included. Regions of interest were drawn on the pelves and bladder, and time-activity curves were generated. The first reflux phase, the bladder volume at first reflux, and the bladder volume at maximal reflux were defined, and reflux percentages were calculated. Dimercaptosuccinic acid (DMSA) scintigraphy findings and urinary tract infections were used for correlation.

RESULTS

New curves from the renal pelvis during bladder filling and bladder emptying were generated and their patterns classified. Episodic reflux to the pelvis was observed on time-activity curves, which demonstrated 4 different emptying patterns during voiding. These patterns were described in detail. Visually, residual activity was present in the renal pelves in 58.8% of patients. The mean number of urinary tract infections per year was 1.07 (range, 0-4; SD, 0.88). The DMSA findings were normal in 57.1% of the patients.

CONCLUSION

We obtained and categorized some new time-activity curve patterns from renal pelves with reflux on radionuclide cystography. Discussing these patterns may help physicians understand the physiology of the reflux and the relationship between infections and reflux.