Patient dose reduction during voiding cystourethrography

Abstract

Voiding cystourethrography (VCUG) is a commonly performed examination in a pediatric uroradiology practice. This article contains suggestions on how the radiation dose to a child from VCUG can be made "as low as reasonably achievable" (ALARA). The pediatric radiologist should consider the appropriateness of the clinical indication before performing VCUG and utilize radiation exposure techniques and parameters during VCUG to reduce radiation exposure to a child. The medical physicist and fluoroscope manufacturer can also work together to optimize a pulsed-fluoroscopy unit and further reduce the radiation exposure. Laboratory and clinical research is necessary to investigate methods that reduce radiation exposures during VCUG, and current research is presented here.

Fig. 1

Comparisons of (a) total radiation exposure, (b) fluoroscopic radiation exposure, (c) recorded image radiation exposure, and (d) fluoroscopy time between the continuous fluoroscopy and GCPFL units for all three groups. Group 1 corresponds to girths in the range 8–0 cm (human newborn to 6-month-old infant), group 2 to girths in the range 12–3 cm (2- to 3-year-old child), and group 3 to girths in the range 15–7 cm (10-year-old child). The radiation exposures are expressed as kerma. Reproduced with the permission of the Radiological Society of North America, ©RSNA, 2006; Ward VL, Barnewolt CE, Strauss KJ, et al (2006) Radiation exposure reduction during voiding cystourethrography in a pediatric porcine model of vesicoureteral reflux. Radiology 238:96–06

Fig. 2

Recorded VCUG images in group 1 (abdominal girth 8–0 cm) that were assigned the best conspicuity score of 1 (i.e., renal calyces, uterovesical junctions, urinary bladder contour, urethra, and bone trabecular pattern all seen with an acceptable low level of noise). Contrast material was infused intravenously to constantly opacify renal collecting systems, ureters, and bladder to simulate vesicoureteral reflux, and the pigs are voiding. a, b Continuous fluoroscopy images obtained with total radiation exposure of 0.73 mGy. a Anteroposterior collimated-down view of right kidney demonstrates vesicoureteral reflux. b Left oblique full-bladder view of the ureterovesical junction. c, d GCPFL images, in a different pig, obtained with total entrance radiation exposure of only 0.078 mGy. c Left oblique full-bladder view of the ureterovesical junction. d Anteroposterior collimated-down view of both kidneys demonstrates vesicoureteral reflux. Reproduced with the permission of the Radiological Society of North America, ©RSNA, 2006; Ward VL, Barnewolt CE, Strauss KJ, et al (2006) Radiation exposure reduction during voiding cystourethrography in a pediatric porcine model of vesicoureteral reflux. Radiology 238:96–06

Fig. 3

Recorded VCUG images in group 2 (abdominal girth 12–3 cm) that were assigned a diagnostic quality score of 1 (i.e., the highest diagnostic quality). Contrast material is in the renal collecting systems, ureters, bladder, and urethra. a, b Continuous fluoroscopy images obtained with total radiation exposure of 1.6 mGy. c, d GCPFL images in the same pig as in a and b, with total entrance radiation exposure of only 0.33 mGy. a, c Left oblique full-bladder views of the ureterovesical junction. b, d Collimated-down views of the left kidney demonstrating vesicoureteral reflux. Reproduced with the permission of the Radiological Society of North America, ©RSNA, 2006; Ward VL, Barnewolt CE, Strauss KJ, et al (2006) Radiation exposure reduction during voiding cystourethrography in a pediatric porcine model of vesicoureteral reflux. Radiology 238:96–06