Editing Bladder Cancer: Diagnosis and Evaluation (section)

== Imaging ==

=== Upper Urinary Tract ===

==== Indications ====

===== 2016 AUA/2021 CUA =====
* '''<span style="color:#ff0000">Recommended (1):</span>''' 
*# '''<span style="color:#ff0000">In the initial workup of all patients suspected to have bladder cancer</span>'''

==== Rationale (2) ====

# '''<span style="color:#ff0000">Identify other sources of hematuria'''
# '''<span style="color:#ff0000">Assess the extravesical urothelium because of the “field change” nature of urothelial carcinoma'''
#* '''In patients with a known history of bladder cancer, upper tract tumors occur in <5% of patients'''
#** The overall incidence of significant findings with imaging of the upper tracts in patients with newly diagnosed bladder cancer is low but increases with tumors of the trigone, CIS, and high-risk disease.

==== Timing ====

* Optimal timing not clear, should likely be risk stratified and generally within 6 months of initial diagnosis.

* '''Usually performed before transurethral resection'''
**If imaging is obtained after transurethral resection, it should be delayed ≈7 days post-procedure to minimize inflammatory artifact, which can be mistaken for T3 disease

===== Modality =====
*'''Contrast-based axial imaging, such as CT or MRI are recommended.'''
** The sensitivity and specificity of CT in detecting nodal metastasis ranges from 31-50% and 68%-100%, respectively
** MRI is generally considered to be more accurate than CT in detecting local tumor stage; however, reports vary in the literature
** Retrograde pyelogram and intravenous urography may also be used when CT or MRI are unavailable.
** US alone may not provide sufficient anatomic detail for upper urinary tract imaging during the work-up of bladder cancer

===== Findings =====
* '''Hydronephrosis on cross-sectional imaging is suspicious for muscle invasion/extravesical disease'''

=== Lower urinary tract imaging ===

===== Modality =====
* MRI is superior to CT at tissue-contrast and staging muscle-invasive vs. non-muscle invasive disease

====== MRI ======
* Protocol includes: T2WI, DWI, contrast enhanced T1
** Muscle is dark on T2
** False positive changes on MRI: BCG changes, post-TUR
** T3 tumor has spiculated appearance on MRI
* Furosemide can be given to help distend the ureter and bladder and potentially improve staging
* Vesical Imaging Reporting and Data System (VI-RADS)
** A 5-point scale used to standardize the interpretation and reporting of bladder cancer on multiparametric magnetic resonance imaging

=== <span style="color:#ff0000">Positron emission tomography and CT (PET/CT)</span> ===
* '''Primary Tumor'''
**'''Limited role as a result of the excretion of standard PET''' (18F-fluorodeoxyglucose) '''into the urine'''
*'''Lymph node metastasis'''
**'''Superior compared to CT'''[https://pubmed.ncbi.nlm.nih.gov/34996595/]
*'''Distant metastasis'''
**'''Superior compared to CT and MR'''[https://pubmed.ncbi.nlm.nih.gov/34996595/]