Diagnostic Ultrasound - Abdomen and Pelvis

Ureteral Duplication
Diagnoses: Urinary Tract
TERMINOLOGY
• Presence of 2 separate pelvicalyceal collecting systems
draining 1 kidney, which may join above bladder (partial),
drain into bladder separately (complete), or beyond bladder
IMAGING
• 2 distinct renal pelves or 2 exiting ureters in single kidney
• 2 central echogenic renal sinuses with intervening bridging
renal parenchyma
• Weigert-Meyer rule: Upper moiety ureter inserts inferior
and medial to lower moiety ureter (85%)
• Result of Weigert-Meyer rule
○ Upper pole tends to obstruct
○ Lower pole tends to have vesicoureteral reflux
TOP DIFFERENTIAL DIAGNOSES
• Column of Bertin
• Segmental multicystic dysplastic kidney
KEY FACTS
PATHOLOGY
• Abnormal bifurcation of ureteral bud arising from
mesonephric duct
CLINICAL ISSUES
• Most often diagnosed on antenatal ultrasound or
incidentally
• Longstanding obstruction, reflux and infection can lead to
secondary hypertension and renal insufficiency/failure
DIAGNOSTIC CHECKLIST
• Young females with recurrent urinary tract infections
• US, IVP or CT/MR urography are imaging modalities of
choice
• VCUG to exclude reflux
(Left) Graphic shows a left
duplex kidney. Upper moiety is
hydronephrotic with
hydroureter draining into a
ureterocele. Note the upper
moiety ureter inserts inferior
and medial to lower moiety
ureter. (Right) Longitudinal US
demonstrates an intervening
bridge of renal tissue, with
two separate renal pelves ſt,
without collecting system
dilatation.
(Left) Longitudinal US
demonstrates a round
anechoic structure in the
upper pole ſt, reflecting a
dilated upper moiety of a
duplex kidney. (Right)
Longitudinal US demonstrates
a dividing prominent band of
renal tissue with dilatation of
the lower moiety ſt,
secondary to reflux.
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