title: Imaging muscle-invasive and metastatic urothelial carcinoma.
abstract: OBJECTIVE
  Muscle-invasive bladder cancer (MIBC) comprises approximately one-third of bladder cancers and is associated with significant morbidity and mortality. Accurate staging of bladder cancer is essential because of significantly different treatment options and the consequences of inaccurate staging. The current recommended method for staging is transurethral resection of the bladder tumor followed by contrast-enhanced computed tomography (CT). In this review, we discuss cross-sectional imaging approaches used to assess local, nodal, and distant metastases in MIBC.
  
  
  RESULTS
  Determining the most accurate imaging method for staging MIBC is a contentious issue. CT with contrast is a practical approach; however, there is potential for understaging of small lymph nodes or foci of metastasis. Multiparametric MRI is emerging as the imaging modality of choice in tumor staging, with a reported accuracy of more than 90%. Locoregional lymph node metastasis can also be accurately evaluated using functional MRI and specific contrast agents with paramagnetic characteristics. PET/CT with conventional radiotracers is a common imaging modality for staging distant metastases.
  
  
  CONCLUSIONS
  Conventional imaging methods for evaluating MIBC are of limited use. However, recent advances in molecular imaging, targeted contrast agents, and functional MRI have shown promising results for the staging of bladder cancer.
authors.affiliation: aRadiology and Imaging Sciences, Clinical Center, National Institutes of Health bGenitourinary Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Ashkan A
authors.initials: AA
authors.lastname: Malayeri
authors.forename: Puskar
authors.initials: P
authors.lastname: Pattanayak
authors.forename: Andrea B
authors.initials: AB
authors.lastname: Apolo
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000556:secondary; D003287:Contrast Media; D003952:Diagnostic Imaging / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009361:Neoplasm Invasiveness; D061206:Neoplasm Micrometastasis; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D019459:Urothelium / Q000000981:diagnostic imaging / Q000473:pathology
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals