title: Bladder cancer: evaluation of staging accuracy using dynamic MRI.
abstract: OBJECTIVE
  To assess the accuracy of magnetic resonance imaging (MRI) in staging bladder cancer and to assess whether dynamic gadolinium-enhanced sequences have any added benefit in staging.
  
  
  METHODS
  Over a 22 month period, the MRI findings of 100 consecutive patients with histologically proven transitional cell carcinoma (TCC) of the bladder were reviewed. The T stage was assessed independently on T2-weighted imaging alone and in combination with gadolinium-enhanced MRI. The final histological diagnosis was considered the reference standard. Statistical analysis was performed to ascertain stage-by-stage accuracy. Accuracy of MRI in differentiating superficial (≤ T1) from invasive (≥ T2) and in differentiating organ-confined (≤ T2) from non-organ-confined (≥ T3) disease was assessed.
  
  
  RESULTS
  On a stage-by-stage basis, tumours were correctly staged using MRI in 63% of patients (observed agreement=0.63, weighted kappa=0.57). The sensitivity and specificity of MRI to differentiate between superficial (≤ T1) from invasive (≥ T2) disease was 78.2 and 93.3%. The observed agreement for this group was 85% (kappa=70%; p<0.0001). The sensitivity and specificity of MRI to differentiate between organ-confined (≤ T2) from non-organ confined (≥ T3) disease was 90.5 and 60%. The observed agreement for this group was 89% (kappa=30%; p<0.01). Gadolinium-enhanced images improved staging in only three patients.
  
  
  CONCLUSIONS
  In the present study MRI was found to be a moderately accurate tool in assessing the T stage. Agreement on a stage-by-stage basis was good. Agreement for differentiating between non-invasive versus muscle-invasive disease was good and that for organ-confined versus non-organ-confined disease was fair. Routine use of gadolinium-enhanced images is not routinely required.
authors.affiliation: Department of Radiology, University Hospitals of Leicester NHS Trust, Leicester General Hospital, UK. arajesh27@hotmail.com
authors.forename: A
authors.initials: A
authors.lastname: Rajesh
authors.forename: H K
authors.initials: HK
authors.lastname: Sokhi
authors.forename: R
authors.initials: R
authors.lastname: Fung
authors.forename: K A
authors.initials: KA
authors.lastname: Mulcahy
authors.forename: M J G
authors.initials: MJ
authors.lastname: Bankart
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002295:Carcinoma, Transitional Cell / Q000473:pathology*; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011300:Preoperative Care; D012015:Reference Standards; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D001749:Urinary Bladder Neoplasms / Q000473:pathology*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA