Diagnostic Ultrasound - Abdomen and Pelvis

Ureterocele
TERMINOLOGY
Definitions
• Cystic balloon-like dilatation of intramural portion of distal
ureter bulging into bladder
• Orthotopic ureterocele (less common): Normal insertion
at trigone and otherwise normal ureter
○ Single ureter system
○ Bilateral in ~ 30% cases
• Ectopic ureterocele (more common): Inserts below
trigone
○ Duplicated collecting system in 80%
– Upper moiety ureter often inserts medial and distal to
superior moiety ureter
– Male: Insertion at bladder neck, prostatic urethra, vas
deferens, or seminal vesicle
□ No wetting in males as insertion always above
external sphincter
– Female: Insertion in distal urethra, vaginal vestibule,
vagina, cervix, uterus, or fallopian tube
□ Wetting in females only if insertion below external
sphincter
○ Single nonduplicated system in 20%
– Small/poorly functioning kidney, may be invisible on
imaging
○ Cecoureterocele: Ectopic submucosal ureterocele
extending to urethra, with intravesical opening
IMAGING
General Features
• Best diagnostic clue
○ Orthotopic: Thin-walled sac-like cystic structure
continuous with distal ureter
○ Ectopic: Continuous with hydronephrotic obstructive
(usually upper) moiety and hydroureter in duplex system
• Location
○ Ectopic: 50% in bladder and 50% in posterior urethra;
10% bilateral
– Males: Insertion always above external sphincter
• Size
○ 1 to a few cm in diameter
• Morphology
○ Smooth, round, or ovoid
Ultrasonographic Findings
• Grayscale ultrasound
○ Thin-walled, cystic intravesical mass continuous with
distal ureter
○ Dilated ureter in ectopic lower moiety, changes in size
with degree of ureteral dilation
○ Midline intravesical tubular structure may be seen,
leading to outlet obstruction (cecoureterocele)
○ Occasionally, in full bladder, ureteroceles may invert,
giving an appearance similar to diverticulum
– Inverted ureterocele reverts to its usual appearance
upon partial emptying of bladder
○ Wall thickening secondary to edema from impacted
stone/infection
○ Ectopic ureteroceles inserting outside bladder mimic
pelvic cyst
• Color Doppler
○ Demonstrates ureteric jet from tip of ureterocele
Radiographic Findings
• Intravenous pyelogram (IVP)/cystography
○ Orthotopic ureterocele: Cobra-head deformity
– Ballooned distal ureter projecting into lumen of
bladder with surrounding radiolucent halo
○ Ectopic ureterocele: Smooth, radiolucent intravesicular
mass mostly near bladder base
– May evert during voiding and mimic diverticulum
– Lumen opacification depends on function of upper
pole moiety
– Drooping lily sign: Displacement of reflux opacified
lower pole moiety by dilated upper pole moiety
– Voiding cystourethrogram may also show reflux in
lower pole moiety in duplex system
CT Findings
• CECT
○ Thin-walled intravesicular cystic mass at ureterovesical
junction (UVJ)
MR Findings
• T2WI
○ Intravesicular cystic mass at UVJ
– Ectopic: May see ectopic insertion into bladder neck,
urethra, vagina, etc.
○ Maximum-intensity projection (MIP) image
demonstrates relative positions of upper and lower
moiety ureters in duplex system
– Superior to demonstrate ectopic ureter extending
from poorly functioning moiety invisible on other
imaging
– Ureterocele may be masked by fluid within urinary
bladder
• Contrast-enhanced MR urography
○ Best for detection of ureterocele in duplex system
○ Intravesicular cyst filled by contrast with surrounding
halo within bladder during early filling phase
○ Continuous with hydronephrotic upper moiety and
hydroureter if function of upper pole moiety preserved
○ Poor or no excretion by upper pole of duplex kidney if
dysplastic
Imaging Recommendations
• Best imaging tool
○ US and CT/MR Urography
• Protocol advice
○ US: Obtain images when bladder is reasonably full
○ Cystogram: Image during early bladder filling; overfilling
may collapse, obscure, or invert low-pressure ureterocele
DIFFERENTIAL DIAGNOSIS
Foley Catheter
• Characteristic shape of Foley catheter with round distal
balloon in bladder
Pseudoureterocele
• From distal ureteral obstruction (stone or tumor), thicker
poorly defined halo/lucency around distal ureter
Diagnoses: Urinary Tract
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