Diagnostic Ultrasound - Abdomen and Pelvis

Ureters and Bladder
– Distended bladder may cause ureteral and
pelvicalyceal dilation and rescanning post void is
beneficial to exclude obstruction
○ Color Doppler evaluation of bladder helps assess normal
ureteral jets and helps exclude complete ureteral
obstruction
• Bladder
○ Recommend fluid intake prior to examination to ensure
optimal distension of urinary bladder
– In fully distended state, urinary bladder is easily
visualized using transabdominal approach
○ Examine patient in supine position with transabdominal
suprapubic approach
– Perform scanning in sagittal and transverse planes
– Patient may be placed in decubitus position, especially
to determine mobility of intravesical masses or debris,
if present
– With smaller volumes, caudal angulation of transducer
is needed to visualize urinary bladder in its retropubic
location
○ Nature of cystic structure in pelvis may be ascertained by
asking patient to void or by inserting Foley catheter
○ In some instances, transvaginal ultrasound may be used
in women for evaluation of suspect bladder neck lesions,
UVJ stone, or ureterocele
○ Advantages of ultrasound
– Radiation-free, real-time assessment with high spatial
resolution of bladder and bladder wall
– Real-time assessment of intraluminal masses in
bladder for mobility and vascularity
– Real-time imaging guidance for bladder intervention,
e.g., placement of percutaneous suprapubic catheters
– Real-time assessment of ureteral jets using color
Doppler imaging; particularly useful in pregnant
patients with dilated collecting system
• Large midline ovarian or pelvic cystic mass may simulate
bladder on transabdominal ultrasound
○ Attention to normal bladder shape, rescanning after
voiding to confirm empty bladder, or transvaginal
imaging is helpful to differentiate
Imaging Pitfalls
• Bladder
○ Reverberation artifacts are commonly encountered
behind anterior wall of urinary bladder
– Appear as regularly spaced lines at increasing depth as
a result of repeated reflection of ultrasound signals
between highly reflective interfaces close to
transducer
– May be reduced or avoided by changing scanning
angle or by moving transducer or using spacer
○ Underdistended bladder may give false impression of
wall thickening and limits intraluminal assessment
CLINICAL IMPLICATIONS
Clinical Importance
• Ureters are at high risk of inadvertent injury during
abdominal or gynecological surgery due to close proximity
to uterine (in uterosacral ligament) and gonadal arteries (at
pelvic brim)
• Ectopic ureter
○ Usually (80%) associated with complete ureteral
duplication; more common in females
○ Ectopic ureteral insertion in females can occur in urethra,
vagina leading to urinary incontinence
○ In complete duplication, upper moeity inserts ectopically
inferiorly and distally to lower moeity (Weigert-Meyer
rule) and can be associated with ureterocele
○ In duplicated system, upper moiety has higher
predisposition to obstruction from ureterocele, while
lower moiety has predisposition to vesicoureteral reflux
• Ureterocele: Cystic dilation of intramural portion of ureter
bulging into bladder
○ Orthotopic: Normal insertion of single ureter
○ Ectopic: Inserts below trigone, mostly in duplicated
system
• Ureteral duplication
○ Bifid ureter drains a duplex kidney but ureters unite
before entering bladder
• Extraperitoneal bladder rupture
○ Urine and blood distend prevesical space (Retzius)
○ Urine often tracks posteriorly into presacral space,
superiorly into retroperitoneal abdomen
○ Usually caused by pelvic fractures
• Intraperitoneal bladder rupture
○ Urine flows up paracolic gutters into peritoneal recesses
and surrounds bowel
○ Usually caused by blunt trauma to an overdistended
bladder
○ Bladder ruptures along dome, which is in contact with
intraperitoneal space
• Patent fetal urachus forms conduit between umbilicus and
bladder
○ Urachus is normally obliterated to form median umbilical
ligament
○ May persist as cyst, diverticulum, or rarely, fistula
○ May become infected or lead to carcinoma
(adenocarcinoma)
• Bladder diverticula are common
○ Congenital: Hutch diverticulum (near ureterovesical
junction)
○ Acquired (usually due to chronic bladder outlet
obstruction), associated with trabeculated bladder wall
○ Can lead to infection, stones, tumor
SELECTED REFERENCES
1. Demir S et al: Value of sonographic anterior-posterior renal pelvis
measurements before and after voiding for predicting vesicoureteral reflux
in children. J Clin Ultrasound. ePub, 2014
2. Butler P, Mitchell A, Healy JC. Applied Radiological Anatomy. Cambridge
University Press. 2012
3. Shimoya K et al: Diagnosis of ureterocele with transvaginal sonography.
Gynecol Obstet Invest. 54(1):58-60, 2002
4. Djavan B et al: Bladder ultrasonography. Semin Urol. 12(4):306-19, 1994
5. Hayden CK Jr et al: Urinary tract infections in childhood: a current imaging
approach. Radiographics. 6(6):1023-38, 1986
6. Glassberg KI et al: Suggested terminology for duplex systems, ectopic
ureters and ureteroceles. J Urol. 132(6):1153-4, 1984
Anatomy: Pelvis
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