title: Combined diffusion-weighted, blood oxygen level-dependent, and dynamic contrast-enhanced MRI for characterization and differentiation of renal cell carcinoma.
abstract: OBJECTIVE
  To investigate a multiparametric magnetic resonance imaging (MRI) approach comprising diffusion-weighted imaging (DWI), blood oxygen-dependent (BOLD), and dynamic contrast-enhanced (DCE) MRI for characterization and differentiation of primary renal cell carcinoma (RCC).
  
  
  METHODS
  Fourteen patients with clear-cell carcinoma and four patients with papillary RCC were examined with DWI, BOLD MRI, and DCE MRI at 1.5T. The apparent diffusion coefficient (ADC) was calculated with a monoexponential decay. The spin-dephasing rate R2* was derived from parametric R2* maps. DCE-MRI was analyzed using a two-compartment exchange model allowing separation of perfusion (plasma flow [FP] and plasma volume [VP]), permeability (permeability surface area product [PS]), and extravascular extracellular volume (VE). Statistical analysis was performed with Wilcoxon signed-rank test, Pearson's correlation coefficient, and receiver operating characteristic curve analysis.
  
  
  RESULTS
  Clear-cell RCC showed higher ADC and lower R2* compared to papillary subtypes, but differences were not significant. FP of clear-cell subtypes was significantly higher than in papillary RCC. Perfusion parameters showed moderate but significant inverse correlation with R2*. VE showed moderate inverse correlation with ADC. Fp and Vp showed best sensitivity for histological differentiation.
  
  
  CONCLUSIONS
  Multiparametric MRI comprising DWI, BOLD, and DCE MRI is feasible for assessment of primary RCC. BOLD moderately correlates to DCE MRI-derived perfusion. ADC shows moderate correlation to the extracellular volume, but does not correlate to tumor oxygenation or perfusion. In this preliminary study DCE-MRI appeared superior to BOLD and DWI for histological differentiation.
authors.affiliation: Department of Clinical Radiology, University Hospitals Munich, Marchioninistrasse 15, 81377 Munich, Germany. mike.notohamiprodjo@med.uni-muenchen.de
authors.forename: Mike
authors.initials: M
authors.lastname: Notohamiprodjo
authors.forename: Michael
authors.initials: M
authors.lastname: Staehler
authors.forename: Nicole
authors.initials: N
authors.lastname: Steiner
authors.forename: Felix
authors.initials: F
authors.lastname: Schwab
authors.forename: Steven P
authors.initials: SP
authors.lastname: Sourbron
authors.forename: Henrik J
authors.initials: HJ
authors.lastname: Michaely
authors.forename: Andreas D
authors.initials: AD
authors.lastname: Helck
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
mesh_terms: D002292:Carcinoma, Renal Cell / Q000378:metabolism* / Q000473:pathology*; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000378:metabolism* / Q000473:pathology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010092:Oximetry / Q000379:methods; D010100:Oxygen / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique
chemical_list: D003287:Contrast Media; D010100:Oxygen