Diagnostic ultrasound ( PDFDrive )

CHAPTER 54 Pediatric Pelvic Sonography 1905
Bladder
Upper pole
“duplication
cyst”
Ureterocele
A
FIG. 54.55 Ectopic Ureterocele. Obstructed upper-pole moiety of a duplex kidney in a baby with urinary tract infection. (A) Sagittal sonogram
of right kidney showing upper-pole “duplication cyst” and mild dilation of the intrarenal collecting system in the lower pole surrounded by normal
parenchyma. (B) Sagittal view of the pelvis demonstrates a large, ectopic ureterocele within the urinary bladder, which is in continuity with the
greatly dilated, tortuous, upper-pole ureter (arrows).
B
in girls, resulting in urinary dribbling. In boys the ectopic ureter
can insert in the proximal urethra, seminal vesicle, vas deferens,
or ejaculatory duct. Urinary incontinence is not a presenting
symptom in boys because the ectopic insertion is always proximal
to the external sphincter. Duplication anomalies are oten
asymptomatic; urinary tract infection (UTI) is the most common
initial presentation. he upper-pole moiety oten becomes
obstructed as a result of an ectopic ureterocele. Sonography
demonstrates a dilated upper-pole collecting system and ureter
that ends distally as a well-deined, thin-walled cystic protuberance
into the bladder base (Fig. 54.55). he lower-pole system is oten
dilated secondary to relux. 196 Less frequently, the lower-pole
moiety may be dilated from obstruction of the ureteral oriice
by the adjacent ectopic ureterocele or because of vesicoureteral
relux. About 10% to 20% of ectopic ureters are associated with
a single collecting system (Fig. 54.56). he renal parenchyma
associated with an ectopic ureter may be dysplastic (containing
echogenic parenchyma, loss of corticomedullary junction, and
variably sized cysts).
Sonography is well suited for screening siblings of patients
with vesicoureteral relux, who are at greater risk of having
relux than the general population. Giel and colleagues 197 showed
that given the seemingly innocuous nature of vesicoureteral relux
in older asymptomatic siblings of known patients with relux,
observation alone in this group is an acceptable form of
management.
Posterior urethral valves are a common cause of urinary
tract obstruction in boys. Signs and symptoms at presentation
include palpable lank masses caused by hydronephrosis or
urinoma, poor urine stream, UTI, and failure to thrive. On
sonography, the bladder has a thick, trabeculated wall, and the
posterior urethra is dilated (Fig. 54.57). here may be marked
hydronephrosis with dilated, tortuous ureters secondary to
vesicoureteral relux. Occasionally, the relux is unilateral, resulting
FIG. 54.56 Simple Ureterocele With Stones in 7-Year-Old Child
With Recent Mild Trauma. Sagittal view of the left side of the bladder
demonstrates a simple ureterocele (arrows) protruding into the bladder
lumen, containing two brightly echogenic, shadowing calculi.
Causes of Bladder Outlet Obstruction
Posterior urethral valves
Prune-belly syndrome
Anterior urethral valves
Urethral duplication or ureterocele
Congenital urethral stricture
Anterior urethral diverticulum
Posterior urethral polyp