Diagnostic Ultrasound - Abdomen and Pelvis

Bladder Carcinoma
TERMINOLOGY
Definitions
• Malignant tumor of bladder
IMAGING
General Features
• Best diagnostic clue
○ Focal bladder wall thickening with intraluminal extension
as mass on US, CT, or MR
Ultrasonographic Findings
• Grayscale ultrasound
○ Focal, immobile, polypoid or broad-based mass along
bladder wall; may present as focal wall thickening
○ Mass may be heterogeneous with mixed echogenicity
• Color Doppler
○ Color Doppler shows increased vascularity in large
tumors, power Doppler may be useful to detect
vascularity in small tumors
• Reported sensitivities range from 50-90%, with higher
sensitivity for tumor > 5 mm
• US may be useful in detection of tumor arising from
bladder diverticulum, provided diverticulum is optimally
fluid filled
○ Diverticular tumor may be inaccessible by cystoscopy
due to narrow neck of diverticulum
• Poor sensitivity in detecting tumors near bladder base in
males with prostatic enlargement
○ Transrectal ultrasound differentiates bladder tumors
from prostatic lesion, although MR has higher sensitivity
○ Bladder tumors and prostatic enlargement may coexist
and bladder tumors may invade prostate
• Transvaginal or transrectal US: To assess bladder wall mass
if suprapubic visualization is poor
○ Poor transabdominal visualization may be due to obesity,
scars on wall, and poor bladder distension
• Recent advances: 3D US rendering may help to discriminate
between superficial and muscle invasive carcinoma
○ Contrast-enhanced ultrasound has shown higher
accuracy than baseline ultrasound
• Negative ultrasound in patient with hematuria and no
identified renal/bladder stone does not exclude bladder
cancer
Radiographic Findings
• IVP
○ Currently less commonly used
○ Scout radiograph may show punctate or speckled
calcification on fronds of villous, papillary tumors, and
linear calcification in sessile tumor
○ Nonspecific filling defects within bladder
○ May be used to detect upper tract disease
• Cystography
○ ± bladder diverticulum (2-10% contain neoplasm)
CT Findings
• Sessile or pedunculated soft tissue mass projecting into
lumen with post-contrast enhancement
○ CTU better delineation as intraluminal filling defect
• ± enlarged (> 10 mm) metastatic lymph nodes; extravesical
tumor extension
• Fine punctate calcification in tumor; may suggest mucinous
adenocarcinoma
• Ring pattern of calcification; may suggest
pheochromocytoma
• Poor accuracy for locoregional spread
• Sensitivity of 85% and specificity of 94% for detecting
bladder tumor
• False-negatives with flat lesion, < 1 cm, local inflammation,
fibrosis, scar tissue
• Urachal adenocarcinoma-lobulated mass arising from
midline ventral dome of bladder with exophytic component
MR Findings
• T1WI
○ Tumor has intermediate signal intensity (isointense to
bladder wall)
○ Bone marrow metastases; similar signal intensity as
primary tumor
• T2WI
○ Tumor has slightly higher signal than bladder wall or
muscle, lower than urine
○ Invasion of prostate, seminal vesicle, rectum, uterus,
vagina: ↑ signal intensity
○ T2 images helpful in determination of tumor infiltration
of perivesical fat
○ Confirm bone marrow metastases
• DWI
○ More accurate than T2WI for organ-confined and higherstage
tumors
○ Low ADC value suggests high-grade tumor; may be used
to assess early treatment response with increased ADC
value
• T1WI C+
○ Early enhancement relative to bladder wall
○ Hyperenhancement of perivesical infiltration, including
nodal and bone invasion
• ± enlarged (> 10 mm) metastatic lymph nodes
• Unable to differentiate stage T1 from stage T2, acute
edema or hyperemia from 1st week post biopsy
• High accuracy for locoregional spread; accuracy ~ 85% in
differentiating nonmuscle-invasive from muscle-invasive
tumor
Imaging Recommendations
• Best imaging tool
○ US: Useful for bladder tumor screening in patients with
schistosomiasis, tumor within diverticulum
○ CTU: Screening upper urinary tract
○ MR: Preferred modality for local staging
DIFFERENTIAL DIAGNOSIS
Benign Prostatic Hypertrophy (BPH)
• Enlarged median lobe of prostate may appear as irregular
mass lying free within bladder in some planes
• On angling transducer caudad, enlarged prostatic median
lobe can be shown to be part of prostate gland
Bladder Sludge/Blood Clot
• Mobile avascular nonshadowing intraluminal mass
Diagnoses: Urinary Tract
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