INTRODUCTION AND OBJECTIVES: To determine if serial ultrasound of the urinary bladder and retrovesical space can correctly diagnose the presence or absence of vesicoureteral reflux (VUR) compared to voiding cystourethrography (VCUG) in children UTI.

METHODS: Patients underwent serial ultrasound of the urinary bladder and retrovesical space every 15 minutes until full bladder and post-void. It was positive if the ureter was visible behind the urinary bladder in one or more of the serial ultrasound examinations and negative if it was not visible. Those with neurogenic bladder and previous VUR diagnosis were excluded. All ultrasound examinations were done by a single operator prior to the VCUG.

RESULTS: From Jan-Oct 2009, 175 children (350 kidney-ureter units) underwent serial ultrasound and VCUG. There were 94 (53.71%) males and 81 (46.29%) females. Ninety six (54.86%) were less than 1 year old (age range: 1 month to 11 years old). Fifty five patients (31.4%) were positive for VUR by VCUG. Reflux had an incidence of 0.24 (84/350). The ultrasound had sensitivity of 69.05% (44.12%, 82.76%, and 90.48% for Gr I-II, Gr III and Gr IV-V VUR respectively) and specificity of 83.08%. The positive predictive value (PPV) was only 56.31%, but it had very good negative predictive value (NPV) of 89.47% (82.48%, 93.85%, and 96.51% for Gr I-II, Gr III, and Gr IV-V respectively). Positive likelihood ratio (LR+) was 4.08 and negative likelihood ratio (LR-) was 0.37.

CONCLUSIONS: Serial ultrasound of the urinary bladder and retrovesical space was able to correctly diagnose most of Grade III-V VUR. It was very good and detecting patient with negative results in VCUG. It cannot be used as a substitute for VCUG because it tends to overly diagnose reflux. But based on our results, it can be used to initially screen patient prior to VCUG to determine who will not actually need the procedure. It can further lessen the number of VCUG’s performed by using it as a monitoring tool for previously diagnosed reflux and as a screening for asymptomatic siblings.

Source of Funding: none