title: Value of diffusion-weighted and gadolinium-enhanced MRI for the diagnosis of pelvic recurrence from colorectal cancer.
abstract: OBJECTIVE
  To prospectively assess the added value of gadolinium-enhanced and diffusion-weighted (DWI) MRI for the diagnosis of pelvic recurrence from colorectal cancer (CRC).
  
  
  METHODS
  Fifty-two patients with suspected pelvic recurrence from CRC underwent pelvic MRI with T2-weighted ("T2"), gadolinium-enhanced fat-suppressed T1-weighted ("gadolinium") and DWI MR sequences. Three readers (senior radiologist: R1, two residents: R2, R3) scored the likelihood of recurrence on "T2," "T2 + DWI," and "T2 + Gadolinium."
  
  
  RESULTS
  Twenty-seven patients had 42 sites of pelvic recurrence. On "T2," R1 achieved AUC of .95, sensitivity 88.4%, specificity 95.2%. For R2, these figures were .89, 81.4%, 90.5%, for R3 .90, 83.7%, 76%. Both Gadolinium injection and DWI significantly improved AUCs for residents but not for the senior radiologist: up to .988 (R2, P = 0.006) and to .98 (R3, P = 0.01) with DWI and to .96 (R2, P = 0.04), .98 (R3, P = 0.01) after gadolinium. All readers achieved slightly better AUCs with "T2 + DWI" than with "T2+Gadolinium" but not significantly (P = 0.68, P = 0.11, P = 0.3; respectively).
  
  
  CONCLUSIONS
  For diagnosis of pelvic recurrence from CRC, both DWI and gadolinium-enhanced MRI significantly increase diagnostic performances compared with "T2" MRI for residents. DWI may be helpful in patients with contra-indications to intravenous administration of gadolinium.
authors: Department of Radiology, Hôpital Robert Debré, Avenue du Général Koenig, Cedex, France.
authors: Alban
authors: A
authors: Colosio
authors: Philippe
authors: P
authors: Soyer
authors: Pascal
authors: P
authors: Rousset
authors: Coralie
authors: C
authors: Barbe
authors: Francis
authors: F
authors: Nguyen
authors: Olivier
authors: O
authors: Bouché
authors: Christine
authors: C
authors: Hoeffel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000628:therapy; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology* / Q000517:prevention & control; D009942:Organometallic Compounds; D010386:Pelvic Neoplasms / Q000473:pathology* / Q000517:prevention & control / Q000556:secondary*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine
keywords: MR imaging; diffusion weighted imaging; rectal cancer recurrence