Comparison of the DRCG and MCU studies in detecting VUR and detection of incidence of renal scarring in children presenting with UTI

Objectives To compare the DRCG and MCU studies in detection of VUR in children with UTI and to determine the incidence of renal scarring in children with VUR.

Methods A prospective study was done in total of 44 children of age 3-14 years with recurrent urinary tract infection or who had high suspicion for reflux or who were confirmed cases of reflux. All the patients underwent three investigations: DRCG(Di-ureteric cysto-urethrogram), MCU micturating cystography, DMSA(99mTechnetium-dimercaptosuccinic acid).VUR was detected by MCU and DRCG whereas scanning with 99mTc-DMSA, was done to detect focal kidney abnormalities, including scars of infectious origin. The MCU & DRCG studies were performed with a difference not more than 15 days. All DMSA studies had been performed at least 3 months after, and all MCU & DRCG studies at least 6 weeks after any known UTI.

Results Reflux was found in 57 (65%) of total of 88 renal units by MCU. Reflux was found in positive in 59 (67%) renal units by DRCG. There was one renal unit that showed reflux on MCU but no reflux was detected when studied by DRCG. However, there were three renal units which showed positive reflux on DRCG but no reflux when studied by MCU. Also, there was one renal unit which showed severe reflux on DRCG but Grade I reflux when studied by MCU. Scarring was found in 46 (80%) renal units out of 57 renal units, which had positive reflux. Scarring was found in positive in 12 (38.7%) renal units out of 31 renal units, which had no reflux when studied by MCU. Scarring was found in 49 renal units out of 59 renal units, which had positive reflux (83%) by DRCG. Scarring was found in positive in 09 renal units out of 29 renal units, which had no reflux when studied by DRCG (31%).

Conclusions DRCG was found to be a sensitive technique for the detection of VUR. There was a direct relationship between the grade of reflux and renal scarring.The study also reveals that there is a cause-and-effect relationship between UTI and renal scarring that is made worse by VUR