Radiation Exposures Compared in Pediatric Exam Methods
In children, continuous fluoroscopy delivers more radiation, is less effective in voiding cystourethrography
FRIDAY, Nov. 21 (HealthDay News) -- Significant differences in radiation exposure and effective doses were noted in children undergoing voiding cystourethrography (VCUG) and radionuclide cystography (RNC), according to a report in the December issue of Radiology.
Valerie L. Ward, M.D., of Harvard Medical School and Children's Hospital Boston, and colleagues retrospectively compared radiation exposure and effective dose in children undergoing VCUG performed with either grid-controlled variable-rate pulsed fluoroscopy (GCPFL) or continuous fluoroscopy (CFL) and RNC. The 145 children (75 girls and 70 boys) were divided into three groups based on their supine anteroposterior abdominal diameter and analysis of variance was utilized to compare radiation exposure and fluoroscopy time.
Overall, GCPFL significantly reduced total radiation exposure, the researchers report. GCPFL exposure was eight times lower than that of CFL with no significant reduction in fluoroscopy time. While effective radiation doses from GCPFL were one order of magnitude lower than effective doses for CFL, RNC effective doses were one order of magnitude lower than GCPFL.
"While some still think fluoroscopy time is a useful representation of radiation exposure during a fluoroscopic examination, the lack of correlation between total radiation exposure and fluoroscopy time with the GCPFL unit in our study refutes this belief," according to the authors. "The relatively small risks of performing VCUG with GCPFL (equivalent to approximately nine days of background radiation at sea level in the United States) or RNC (equivalent to approximately one day of background radiation at sea level in the United States) in a young child must be weighed against the clinical indication for the examination and the clinical benefits of obtaining the necessary diagnostic information from the examination."