9%20ECOGRAFIA%20ABDOMINAL%20COMO%20CUANDO%20DONDE

THE PAEDIATRIC ABDOMEN 227
A
B
C
D
Figure 9.10 (A) Mild PCS dilatation due to reflux. (B) The right lower ureter is dilated (arrowheads) and urine was
seen to reflux back up the ureter, dilating the kidney. (C) Bilateral reflux (right worse than left) is observed in a TS
through the base of the bladder. Both ureters (arrows) are seen to dilate intermittently. (D) Compare (C) with a normal
patient, in whom the vesicoureteric junctions can be identified by the presence of jets on colour Doppler. No ureteric
dilatation can be demonstrated either before or after micturition.
(Continued)
severe. 15 Conversely, after the first year of life
reflux is more likely to present in girls and is often
less severe. Vesicoureteric reflux is a common
cause of hydronephrosis antenatally, accounting
for up to 38% of all prenatal urinary tract dilatations,
requiring ultrasound follow-up and antibiotic
prophylaxis. 16,17
Reflux may either be due to a developmental
anomaly at the vesicoureteric junction, or the
result of a neurogenic bladder, partial outlet
obstruction or foreign bodies such as calculi and
the presence of a catheter.
Children who have had one or more episodes of
urinary tract infection should be investigated to
search for an underlying cause and to identify evidence
of reflux nephropathy (Tables 9.2 and 9.3).
Approximately 2% of boys and 8% of girls will
develop at least one urinary tract infection by 10
years of age, requiring investigation, and in most
centres will account for a substantial proportion of
the paediatric sonography performed.
Reflux itself is not reliably diagnosed by ultrasound
as it is possible to have intermittent reflux in
the presence of a normal ultrasound scan, with a