title: Correlations of dynamic contrast-enhanced magnetic resonance imaging with morphologic, angiogenic, and molecular prognostic factors in rectal cancer.
abstract: OBJECTIVE
  To investigate the correlations between parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and prognostic factors in rectal cancer.
  
  
  METHODS
  We studied 29 patients with rectal cancer who underwent gadolinium contrast-enhanced, T1-weighted DCE-MRI with a three Tesla scanner prior to surgery. Signal intensity on DCE-MRI was independently measured by two observers to examine reproducibility. A time-signal intensity curve was generated, from which four semiquantitative parameters were calculated: steepest slope (SLP), time to peak (Tp), relative enhancement during a rapid rise (Erise), and maximal enhancement (Emax). Morphologic prognostic factors including T stage, N stage, and histologic grade were identified. Tumor angiogenesis was evaluated in terms of microvessel count (MVC) and microvessel area (MVA) by morphometric study. As molecular factors, the mutation status of the K-ras oncogene and microsatellite instability were assessed. DCE-MRI parameters were correlated with each prognostic factor using bivariate correlation analysis. A p-value of <0.05 was considered significant.
  
  
  RESULTS
  Erise was significantly correlated with N stage (r=-0.387 and -0.393, respectively, for two independent data), and Tp was significantly correlated with histologic grade (r=0.466 and 0.489, respectively). MVA was significantly correlated with SLP (r= -0.532 and -0.535, respectively) and Erise (r=-0.511 and -0.446, respectively). MVC was significantly correlated with Emax (r=-0.435 and -0.386, respectively). No significant correlations were found between DCE-MRI parameters and T stage, K-ras mutation, or microsatellite instability.
  
  
  CONCLUSIONS
  DCE-MRI may provide useful prognostic information in terms of histologic differentiation and angiogenesis in rectal cancer.
authors.affiliation: Department of Medicine, Graduate School, Yonsei University, Seodaemun-gu, Seoul, Korea.
authors.forename: Hye-Suk
authors.initials: HS
authors.lastname: Hong
authors.forename: Se Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Hae-Jeong
authors.initials: HJ
authors.lastname: Park
authors.forename: Mi-Suk
authors.initials: MS
authors.lastname: Park
authors.forename: Ki Whang
authors.initials: KW
authors.lastname: Kim
authors.forename: Won Ho
authors.initials: WH
authors.lastname: Kim
authors.forename: Nam Kyu
authors.initials: NK
authors.lastname: Kim
authors.forename: Jae Mun
authors.initials: JM
authors.lastname: Lee
authors.forename: Hyeon Je
authors.initials: HJ
authors.lastname: Cho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002454:Cell Differentiation; D003287:Contrast Media / Q000494:pharmacology*; D004252:DNA Mutational Analysis; D005260:Female; D005682:Gadolinium / Q000494:pharmacology; D011905:Genes, ras; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008833:Microcirculation; D053842:Microsatellite Instability; D008875:Middle Aged; D009367:Neoplasm Staging; D009389:Neovascularization, Pathologic; D011379:Prognosis; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology*; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D003287:Contrast Media; D005682:Gadolinium