title: Assessment of Semiquantitative Parameters of Dynamic Contrast-Enhanced Perfusion MR Imaging in Differentiation of Subtypes of Renal Cell Carcinoma.
abstract: BACKGROUND
  To assess semiquantitative parameters of dynamic contrast-enhanced perfusion MR imaging (DCE) in differentiation of subtypes of renal cell carcinoma (RCC).
  
  
  METHODS
  Prospective study conducted upon 34 patients (27 M, 7 F, aged 25-72 ys: mean 45 ys) with RCC. Abdominal dynamic contrast-enhanced gradient-recalled echo MR sequence after administration of gadopentetate dimeglumine was obtained. The time signal intensity curve (TIC) of the lesion was created with calculation of enhancement ratio (ER), and washout ratio (WR).
  
  
  RESULTS
  The subtypes of RCC were as follows: clear cell carcinomas (n=23), papillary carcinomas (n=6), and chromophobe carcinomas (n=5). The mean ER of clear cell, papillary and chromophobe RCC were 188±49.7, 35±8.9, and 120±41.6 respectively. The mean WR of clear cell, papillary and chromophobe RCCs were 28.6±6.8, 47.6±5.7 and 42.7±10, respectively. There was a significant difference in ER (P=0.001) and WR (P=0.001) between clear cell RCC and other subtypes of RCC. The threshold values of ER and WR used for differentiating clear cell RCC from other subtypes of RCC were 142 and 38 with areas under the curve of 0.937 and 0.895, respectively.
  
  
  CONCLUSIONS
  We concluded that ER and WR are semiquantitative perfusion parameters useful in differentiation of clear cell RCC from chromophobe and papillary RCCs.
authors.affiliation: Department of Diagnostic Radiology, Mansoura University Hospital of Mansoura, Faculty of Medicine, Mansoura, Egypt.
authors.forename: Ahmed Abdel Khalek
authors.initials: AA
authors.lastname: Abdel Razek
authors.affiliation: Department of Diagnostic Radiology, Mansoura University Hospital of Mansoura, Faculty of Medicine, Mansoura, Egypt.
authors.forename: Amani
authors.initials: A
authors.lastname: Mousa
authors.affiliation: Department of Diagnostic Radiology, Mansoura Urology and Nephrology Center, Mansoura, Egypt.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Farouk
authors.affiliation: Department of Diagnostic Radiology, Mansoura Urology and Nephrology Center, Mansoura, Egypt.
authors.forename: Nancy
authors.initials: N
authors.lastname: Nabil
keywords: Carcinoma, Renal Cell; Cell Differentiation; Magnetic Resonance Imaging