Vesicoureteral reflux grading in contrast-enhanced voiding urosonography

Area of Science:

• Pediatric imaging
• Urology
• Diagnostic radiology

Background:

• Contrast-enhanced voiding urosonography (VUS) is increasingly used for diagnosing vesicoureteral reflux (VUR).
• VUS reduces the need for voiding cystourethrography (VCUG), making reflux grading in VUS more relevant.
• Standardized grading of VUR in VUS is needed to correlate with established VCUG grading systems.

Purpose of the Study:

• To identify sonomorphologic and sonomorphometric parameters correlating with VUR grading in VCUG.
• To propose a VUS-based reflux grading system.
• To compare the proposed VUS grading system with the international VCUG grading system.

Main Methods:

• 186 children underwent both VUS and VCUG.
• VUS utilized intravesical ultrasound contrast medium (Levovist).
• Ureteral and pelvicalyceal dilatations, renal pelvic diameter, and microbubble density were assessed. A VUS grading system was developed, incorporating urinary tract dilation status.

Main Results:

• No sonomorphologic/sonomorphometric parameters simplified VUS reflux grading.
• VUS and VCUG grades agreed in 62% of kidney-ureter-units (KUUs).
• VUS graded reflux lower in 11% and higher in 27% of KUUs compared to VCUG. 70% of VCUG grade I were VUS grade II.

Conclusions:

• A VUS reflux grading system analogous to VCUG can be implemented.
• Adding urinary tract dilation status (dilated vs. non-dilated) enhances VUS reflux grading.
• Many VUR cases classified as grade I by VCUG appear to be grade II or higher by VUS.