Diagnostic Ultrasound - Abdomen and Pelvis

Bladder Diverticulum
TERMINOLOGY
Abbreviations
• Bladder diverticula/outpouching
Definitions
• Saccular outpouching from herniation of bladder mucosa
and submucosa through muscular wall of bladder
• Communicates with bladder lumen via wide or narrow neck
IMAGING
General Features
• Best diagnostic clue
○ Perivesical cystic mass with communication to bladder
lumen
• Location
○ Most commonly near ureterovesical junction (UVJ)
• Size
○ Variable size; can exceed size of bladder
• Morphology
○ Single or multiple
○ Smooth wall
Ultrasonographic Findings
• Grayscale ultrasound
○ Anechoic outpouching from bladder with narrow or wide
neck
○ May empty with micturition
○ Internal echogenicity of diverticulum varies depending
on its contents
○ May contain calculi, hematoma, or tumor
• Color Doppler
○ Urine may be seen flowing into and out of diverticulum
– Color Doppler jet connecting bladder to diverticulum
very useful to distinguish diverticulum from other
paravesical masses
– Power Doppler may show vascularity within tumors
that can mimic bladder diverticulum
Radiographic Findings
• IVP
○ Opacifies with excreted contrast unless obstructed
○ Medial deviation of ipsilateral ureter
○ Intraluminal stones, debris, or tumor appear as filling
defects
• Cystogram
○ Oblique films may show configuration of diverticulum
neck
Fluoroscopic Findings
• Voiding cystourethrogram
○ Rarely used, evaluates diverticulum if ultrasound cannot
differentiate it from pelvic/adnexal cyst
CT Findings
• CECT
○ Fluid attenuation outpouching from bladder
○ Usually fills with contrast on excretory phase (CT
urogram)
MR Findings
• T1WI
○ Exophytic low-intensity mass isointense to urine
• T2WI
○ High signal mass contiguous with bladder
○ May see dephasing with motion of urine flowing
between it and bladder lumen
Imaging Recommendations
• Best imaging tool
○ Ultrasound, CT urogram
• Protocol advice
○ Check emptying of diverticulum on post-void studies
DIFFERENTIAL DIAGNOSIS
Urachus
• Cord-like embryonic remnant that connects anterior
bladder dome with umbilicus
• Characteristic midline position
• Depending on patency can be seen as diverticulum, cyst, or
fistula
Everted Ureterocele
• Continuous with ureter
• Assumes its more usual appearance of bulging into bladder
upon partial bladder emptying
Paraovarian Cysts in Female
• Vestigial remnant of Wolffian duct in mesosalpinx
• No communication with bladder
• No change with micturition
Pelvic Cysts in Male
• Transrectal US defines origins and shows no
communication with bladder
• Prostatic utricle cyst
○ Dilatation of prostatic utricle
○ Midline
○ Associated with urogenital anomalies
• Müllerian cyst
○ Arise from remnants of müllerian duct
○ May extend lateral to midline
• Seminal vesicle cyst
○ Wolffian duct anomaly
○ Usually large and solitary
PATHOLOGY
General Features
• Etiology
○ Acquired: Most common secondary to chronic bladder
outlet obstruction (60%)
– Associated with weakening of muscle layers from
long-standing bladder outlet obstruction
– Children
□ Posterior urethral valves
□ Large ureterocele
□ Neurogenic bladder
□ Bladder neck stenosis
– Adults
□ Secondary to prostatic enlargement
□ Post-traumatic urethral stricture
□ Neurogenic bladder
Diagnoses: Urinary Tract
543