Pediatric Vesicoureteral Reflux

Etiology:
— Incompetent vesicoureteral valve
— Ureteral insertion into ureterocele or bladder diverticulum
Imaging VCUG Grading:
— Grade I: Reflux only in ureter
— Grade II: Reflux into non-dilated collecting system
— Grade III: Rreflux into mildly dilated collecting system
— Grade IV: Reflux into moderately dilated collecting system
— Grade V: Reflux into markedly dilated collecting system
Radionuclide Cystogram:
— Less spatial resolution than VCUG but has lower radiation dose and continuous monitoring
— Excellent for following reflux once it is diagnosed
Imaging US:
— Artificial collagen injection mounds at ureterovesical junction appear as echogenic bump at base of bladder
— Artificial collagen injection mounds can become calcified
DDX: Artificial collagen injection mounds can become calcified and mimic stones
Complications: Artificial collagen injection mounds at ureterovesical junction can cause ureteral obstruction
Treament:
— Lower grades of reflux can be treated temporarily with artificial collagen injections at ureterovesical junction
— Higher grades of reflux require surgery
Clinical: Lower grades of reflux usually resolve on their own as patient grows older

Radiology Cases of Vesicoureteral Reflux

Radiology Cases of Incorrect Position of a Urinary Catheter For the Performance of a Voiding Cystourethrogram

VCUG showing a vaginogram — Scout image from a voiding cystourethogram exam (above) shows a urinary catheter looped within the pelvis. AP image (below left) obtained after the introduction of contrast through the catheter shows filling of a structure that does not conform to the expected contour of the bladder and whose inferior aspect lies very low in the pelvis. Lateral image (below right) shows a filling defect on the superior aspect of the structure which represents the cervix projecting into a contrast-filled vagina.

Radiology Cases of Vesicoureteral Reflux Grade I

Radiology Cases of Vesicoureteral Reflux Grade II

Radiology Cases of Vesicoureteral Reflux Grade II Due to Posterior Urethral Valves

VCUG of posterior urethral valves — Oblique image from a voiding cystourethrogram (left) shows left vesicoureteral reflux up into a non-dilated left renal collecting system (Grade 2 vesicoureteral reflux). The posterior urethra appears dilated. Magnified lateral image of the urethra (right) shows the dilation of the posterior urethra is due to a fixed narrowing in the posterior urethra.

Radiology Cases of Vesicoureteral Reflux Grade III

US of acute pyelonephritis / acute lobar nephronia — Sagittal US of the right kidney (above) shows an ill-defined hypoechoic mass in the right upper pole that is obscuring the normal outline of the echogenic fat in the renal hilum. The mass was hypoperfused on color and power doppler US. AP image from a voiding cystourethrogram (below) shows bilateral vesicoureteral reflux, grade II on the left and grade III on the right

US and VCUG of vesicoureteral reflux and neurogenic bladder — Sagittal US of the right kidney (above) shows moderate hydronephrosis. AP image from a voiding cystourethrogram (below) shows right-sided vesicoureteral reflux into a dilated collecting system and a trabeculated bladder. The urethra was normal in appearance.

VCUG of ectopic ureter inserting into the urethra — Sagittal US of the right kidney (above left) is normal while sagittal US of the left kidney (above right) shows a parenchymal bar between the upper and lower pole collecting systems. AP image of the bladder (below left) obtained during filling of the bladder during a voiding cystourethrogram (VCUG) shows right-sided vesicoureteral reflux into a dilated collecting system with the right ureter inserting normally into the base of the bladder. AP image of the bladder (below right) obtained during the voiding phase of the VCUG shows new left-sided grade I vesicoureteral reflux with the left ureter inserting into the urethra.

VCUG of bilateral vesicoureteral reflux — AP image from a voiding cystourethrogram exam shows bilateral vesicoureteral reflux up to the level of the single bilateral renal collecting systems, which are moderately dilated. There were normal ureteral insertions present bilaterally.

Radiology Cases of Vesicoureteral Reflux Grade IV

CT of reflux nephropathy and VCUG of vesicoureteral reflux — Coronal CT with contrast of the abdomen (left) shows a normal appearing left kidney and a shrunken right kidney with diffuse loss of renal parenchyma and scarring. AP image from a voiding cystourethrogram (right) shows left grade II vesicoureteral reflux and right grade IV vesicoureteral reflux.

US of cystic renal dysplasia — Sagittal US of the kidneys (above) show small echogenic kidneys bilaterally with some cysts but no hydronephrosis. AP image from a VCUG (below left) shows bilateral grade 4 vesicoureteral reflux with intrarenal reflux and the bladder is trabeculated. Lateral image from the VCUG (below right) shows a urachal diverticulum arising from the dome of the bladder anteriorly. The urethra was normal.

Radiology Cases of Vesicoureteral Reflux Grade V

VCUG of ectopic ureterocele — AP images from a voiding cystourethrogram (above) show a lucent filling defect in the base of the bladder. Oblique image (below) shows reflux into an extremely dilated right renal collecting system. The right ureter inserts into a dilated structure that is inside and outside of the bladder.

Radiology Cases of Vesicoureteral Reflux Grade V Due to Posterior Urethral Valves

VCUG of posterior urethral valves — AP image from a voiding cystourethrogram (above) shows bilateral grade 5 vesicoureteral reflux, right greater than left, and a narrow pinecone-shaped bladder in the inferior midline aspect of the image. Lateral image of the urethra taken during the voiding phase of the voiding urethrogram (below) shows marked dilation of the posterior urethra and a thin lucent membrane at the transition zone where the urethra assumes a more normal caliber.

Radiology Cases of Vesicoureteral Reflux Grade V and Urine Ascites Due to Posterior Urethral Valves

VCUG of urine ascities — AXR scout image (left) shows centralization of mildly distended bowel loops. AP image obtained at the end of a voiding cystourethrogram (right) shows left Grade V vesicoureteral reflux. The overall density of the abdomen is increased in the interval due to contrast extravasation out of the renal collecting system and extravasated contrast is outlining loops of bowel and can be seen tracking up the right lateral aspect of the abdomen.

Radiology Cases of Vesicoureteral Reflux Treated with Deflux Injections

US of bilateral Deflux mounds in the bladder — Transverse US of the bladder shows two round echogenic lesions located along the posterior aspect of the bladder.

Radiology Cases of Left Vesicoureteral Reflux Treated with Deflux Injection Causing Left Acute Ureteral Obstruction

US of acute ureteral obstruction after Deflux injection — Sagittal US of the right kidney (above left) was normal. Sagittal US of the left kidney (above right) showed new moderate hydronephrosis. Transverse US of the bladder (below left) showed a normal right ureteral jet. Transverse US of the bladder (below right) shows an oval echogenic structure near the left ureterovesical junction at the base of the bladder and a left ureteral jet which is markedly less than its counterpart on the right.