title: [Intravoxel incoherent motion dwi in renal tumors: differentiation between benign and malignant masses].
abstract: OBJECTIVE
  To evaluate the performance of intravoxel incoherent motion (IVIM) diffusion-weighted MR imaging in the differential diagnosis of Angiomyolipoma (AML), clear cell renal cell carcinoma (clear cell RCC) and non-clear cell renal cell carcinoma (non-clear cell RCC).
  
  
  METHODS
  Forty-five patients were enrolled and classified into three groups according to the surgical pathology results. There were even amount of subjects (15) in each group of AML group, clear cell RCC group and non-clear cell RCC group (including 6 Papillary RCC and 9 Chromophobe RCC). ALL the patients underwent respiratory-triggered DWI on 3.0T MR system using multi b-values of 0, 20, 50, 100, 150, 200, 400, 600, 800 sec/mm2. Pure molecular-based (D), perfusion-related (D*) and vascular fraction (f) were calculated using a bi-exponential model. Comparisons of derived parameters derived by IVIM-DWI among three groups were performed using One-way ANOVA.
  
  
  RESULTS
  D in clear cell RCC (1.8±1.5)×10(-3) mm2/s was significantly higher than that in AML (0.7±0.3)×10(-3) mm2/s or non-clear cell RCC (0.9±0.3)×10(-3) mm2/s (P<0.05), while no statistical difference was observed between AML and non-clear cell RCC (P=0.807). D* demonstrated significant difference between AML (33.3±18.2)×10(-3) mm2/s and non-clear cell RCC (17.8±17.3)×10(-3) mm2/s, (P<0.05). No observed significant difference in f was revealed between any two groups.
  
  
  CONCLUSIONS
  Pure water molecules (true diffusion) and capillary microcirculation (pseudo-diffusion) may result in the observed difference of parameters in these three types of renal tumors. D value can contribute to differentiate the clear cell RCC from AML, and between clear cell and non-clear cell RCC as well. D* value may be applied to differentiate AML from non-clear cell RCC.
authors.affiliation: Department of Radiology, the General Hospital of the People's Liberation Army, Beijing 100853, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Radiology, the General Hospital of the People's Liberation Army, Beijing 100853, China.
authors.forename: Haiyi
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Radiology, the General Hospital of the People's Liberation Army, Beijing 100853, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Pan
authors.affiliation: Department of Radiology, the General Hospital of the People's Liberation Army, Beijing 100853, China.
authors.forename: Yehuan
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Radiology, the General Hospital of the People's Liberation Army, Beijing 100853, China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Radiology, the General Hospital of the People's Liberation Army, Beijing 100853, China; Email: yehuiyi301@aliyun.com.
authors.forename: Huiyi
authors.initials: H
authors.lastname: Ye
mesh_terms: D018207:Angiomyolipoma; D002292:Carcinoma, Renal Cell; D003937:Diagnosis, Differential; D006801:Humans; D007680:Kidney Neoplasms