USG shows a hydronephrotic upper
moiety of the right kidney (Fig 1). Color Doppler
study shows a reversal of color, indicating vesico-ureteric reflux (Fig
2).
Diagnosis
Duplex collecting system of the
kidney with VU reflux
Discussion
Duplex collecting system is the most common congenital anomaly of the
urinary tract.
Duplication can be complete (2 ureters with two separate ureteral
orifices) and
incomplete (when ureters join and enter the bladder together in a single
ureteric orifice).
As a general rule, the upper moiety (ectopic ureter) is prone for
formation of ureterocele
(with or without VU reflux), while the lower moiety is prone for VU
reflux.
VU Reflux on
Color Doppler
Ureteral jets are easily perceptible by CD imaging. For demonstration of
reflux, the
patient should be adequately hydrated. The ureteral orifice should be
located in the
urinary bladder by real time imaging, and the scan plane should be so
adjusted so that
the lower ureter is seen entering the urinary bladder (lengthwise
imaging). The ureteral jet
should then be observed on CD imaging. Adult patients and
co-operative children should
be instructed to perform the Valsalva’s manouevre immediately after the
jet is observed.
Infants can be scanned when they are crying. Reversal of flow indicated VU
reflux.
Dr. Alpana Joshi,
Associate Professor, BYL Nair Hospital, Mumbai
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