Efficacy of Fluoroscopic Screen Capture Images in Evaluation of Abnormality during Voiding Cystourethrography in Pediatric Population
Kriengkrai Iemsawatdikul MD*, Pira Neungton MD*, Preeyacha Pacharn MD*, Chirawat Sudla Bsc, RT*, Apichart Kraklangchon RT*, Koedsiri Thamnumsook RN*, Piyamaporn Wannurak RN*, Yajai Thrisoontron PN*
Affiliation : * Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Background : Children’s risk of adverse radiation effects is greater than adults. All radiologic examinations should be
performed with lowest radiation dosage possible. Screen image capture is a new way for image documentation that could
minimize radiation exposure during voiding cystourethrography (VCUG).
Objective : To evaluate the effectiveness of fluoroscopic capture spot (FCS) image in diagnosing vesicoureteral reflux (VUR)
and other urinary tract pathologies during VCUG in the pediatric population.
Material and Method: The study was done prospectively in 248 VCUG examinations. Each test consisted of FCS images
and the corresponding digital radiographic spot (DRS) images taken nearly simultaneously. Each set of data was reviewed
by three pediatric radiologists for the diagnosis of VUR, urinary tract pathologies, presence of a fistula, and other
abnormalities. By using DRS images as a gold standard, the effectiveness of FCS images was evaluated. The present study
protocol was approved by the Ethics Committee of Faculty of Medicine Siriraj Hospital, Mahidol University (Si073/2012).
Results : There was no significant difference between FCS and DRS images in defining grade of VUR (p = 0.194). FCS and
DRS diagnostics were in perfect agreements when diagnosing the presence or absence of VUR, urinary tract pathologies
(kidney, ureter, bladder, urethra), presence or absence of fistula, and other abnormalities. When images classified as
non-significant VUR (no VUR, grade 1 VUR) or significant VUR (VUR grade 2-5), accuracy, sensitivity, specificity, positive
predictive value (PPV), and negative predictive value (NPV) for diagnosing the non-significant VUR were 99.1%, 100%,
96.7%, 98.9%, and 100%, respectively. When images classified as negative/ low-grade VUR (grade 1-2) or moderate/high
grade VUR (VUR grade 3-5), accuracy, sensitivity, specificity, PPV, and NPV for diagnosing negative/low-grade VUR were
99.7%, 100%, 98.8%, 99.8%, and 100%, respectively. There were excellent correlations among three readers.
Conclusion : Image from fluoroscopic capture spot technology is sufficient to diagnose VUR and non-VUR urinary tract
abnormality on VCUG examination.
Keywords : Voiding cystourethrography, Vesicoureteral reflux, Radiation dose reduction, Children, Urinary tract abnormality
