Can careful ultrasound examination of the urinary tract exclude vesicoureteric reflux in the neonate?

Abstract

The aim of the study was to determine whether a urinary tract appearing normal when assessed by meticulous ultrasound (US) examination may coexist with vesicoureteric reflux (VUR) and whether a normal US scan can be used to exclude VUR, thereby avoiding unnecessary voiding cystourethrography (VCUG). The US features of 35 neonates with known VUR were reviewed. Criteria studied included pelvic dilatation above 7 mm on a transverse scan, calyceal or ureteral dilatation, pelvic or ureteral wall thickening, absence of the corticomedullary differentiation (CMD) and signs of renal dysplasia (small kidney, thinned or hyperechoic cortex and cortical cysts); all signs that have been shown to result from or to be associated with VUR. 57 refluxing renal units (RRU) were found among the 35 patients. VUR was bilateral in 22. Among the 57 RRU, at least one US anomaly that would have prompted VCUG was present in 50 (87.7%). Pelvic dilatation above 7 mm was present in 29 RRU (50.9%) only. Calyceal dilatation was present in 24 RRU, the dilatation involving the calyces but not the renal pelvis in seven. Ureteral dilatation was observed in 15 RRU. Pelvic or ureteral wall thickening was present in seven RRU. CMD was absent in 32 RRU (56.1%). US signs of dysplasia were found in 19 RRU. No US anomaly was found in seven RRU (12.3%) in six patients. A careful and meticulous US examination of the neonatal urinary tract allows the detection of over 87% of RRU by showing at least one sonographic abnormality. It is concluded that a normal appearing urinary tract on US does not usually coexist with VUR and that in such cases VCUG is not necessary.

Is Ureter Visualization Possible on Tc-99m DMSA Scintigraphy with Vesicoureteral Reflux Patients?

“…VUR is the most common cause of antenatal hydronephrosis for 40% of intrauterin cases [12]. 30% of the children with attack of acute pyelonephritis had also VUR [13].…”

“…By USG examination, findings of pelvic and/or calyceal dilatation, ureteral dilatation, pelvic and/or ureteral wall thickening are to be considered as warning for VUR. Normal appearing urinary tract normally does not usually coexist with VUR [12]. VUR may effect the growth of kidneys.…”

The Role of Renal Ultrasound in Children With Febrile Urinary Tract Infection

“…All abnormal US findings were recorded, including ≥ 7-mm anteroposterior diameter of the renal pelvis, and/or any grade of dilatation of the calyces or ureters irrespective of anteroposterior diameter; pelvic or ureteral wall thickening; absence of cortico-medullary differentiation; irregular renal outline and signs of renal hypoplasia (i.e., small kidney and thinned or hyperechoic cortex); duplicated renal collecting system, abnormal kidney size, renal cysts, dysplastic kidney, stenosis of the ureteropelvic junction, or ureterovesical junction and ureterocele [21].…”

Serum Procalcitonin Level is a Useful Predictor of Dilating Vesicoureteral Reflux in Patients with First Febrile Urinary Tract Infection

“…Renal Ultrasonography (US) alone is not satisfactory for predicting VUR in young children with febrile UTI [17]. Dimercaptosuccinic acid (DMSA) renal scan can be a good alternative for VCUG as dilating VUR rarely present in children with normal DMSA scans [18][19][20][21].…”

“…Patients were divided into those without VUR, with low-grade VUR (grades 1 and 2), and patients with high-grade VUR (grade 3 and higher) [30]. Dilating VUR was defi ned as VUR grade III or higher [10,17]. US and VCUG were interpreted by a single, experienced pediatric radiologist who was blinded to the patient's clinical and laboratory fi ndings and the study.…”