Comparison of Urinary Tract Dilatation and Society of Fetal Urology systems in the detection of vesicourethral reflux and renal scar

Introduction
The presence and degree of hydronephrosis is very important in the management of many diseases of the urinary tract. In this study, we aim to compare the sensitivity and specificity of 2 classification systems that are used for hydro­nephrosis grading in ultrasound, for reflux and scar detection. The classification systems were the Society of Fetal Urology (SFU) and Urinary Tract Dilatation (UTD).

Material and methods
Ultrasounds and dimercaptosuccinic acid scintigraphies (DMSA) of all patients who underwent voiding cystourethrogram (VCUG) due to urinary tract infection were examined retrospectively. DMSA was accepted for scar detection and VCUG for reflux detection as reference methods. SFU classification was used for hydronephrosis in ultrasound reports, and UTD classification was made over the reports. Sensitivity, specificity, and positive and negative predictive values of UTD and SFU classification systems for reflux and scar detection were calculated, and these 2 systems were compared.

Results
103 (39%) of the patients were male and 162 (61%) were female. Pathologies were detected in 192 (35%) of 530 kidneys in ultrasound. In 110 (42%) of the children, reflux was detected in VCUG. Scars in DMSA were detected in only 16% (44) of 266 kidneys. Sensitivity, positive and negative predictive values of the UTD classification system were statistically significantly higher than the SFU system for scar and reflux detection (p < 0.01).

Conclusions
If we use the UTD system in ultrasounds of patients with urinary tract infections, children reported as UTD 0 may not need VCUG, which reduces radiation exposure to children and the cost of the diagnostic interventions.