title: Monoexponential, biexponential, and stretched exponential diffusion-weighted imaging models: Quantitative biomarkers for differentiating renal clear cell carcinoma and minimal fat angiomyolipoma.
abstract: To determine the utility of various diffusion parameters obtained from monoexponential, biexponential, and stretched exponential diffusion-weighted imaging (DWI) models in differentiating between minimal fat angiomyolipoma (MFAML) and clear cell renal cell carcinoma (ccRCC).
  
  
  
  One hundred thirty-one patients with pathologically confirmed MFAML (n = 27) or ccRCC (n = 104) underwent multi-b value DWI (0∼1700 s/mm2) imaging at 3.0 Tesla MRI. An isotropic apparent diffusion coefficient (ADC) was calculated from diffusion-weighted images by using a monoexponential model. A pseudo-ADC (Dp), true ADC (Dt), and perfusion fraction (fp) were calculated from diffusion-weighted images by using a biexponential model. A water molecular diffusion heterogeneity index (α) and distributed diffusion coefficient (DDC) were calculated from diffusion-weighted images by using a stretched exponential model. All parameters were compared between MFAML and ccRCC by using the Student's t test. Receiver operating characteristic and intraclass correlation coefficient analysis were used for statistical evaluations.
  
  
  
  ADC, Dt, and α values were significantly lower in the MFAML group than in the ccRCC group (P < 0.001). Dp, fp, and DDC values were slightly higher in the MFAML group than in the ccRCC group; however, the difference was not significant (P = 0.136, 0.090, and 0.424, respectively). The AUC values for both α (0.953) and Dt(0.964) were significantly higher than those for ADC (0860), Dp(0.605), fp(0.596), and DDC (0.477) in the differentiation of MFAML from ccRCC (P < 0.001).
  
  
  
  Water molecular diffusion heterogeneity index (α) and Dtmay provide additional information and could lead to improved differentiation with better sensitivity and specificity between MFAML and ccRCC compared with conventional diffusion parameters.
  
  
  
  3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:240-247.
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Haojie
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Liang
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Anqin
authors.initials: A
authors.lastname: Li
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Daoyu
authors.initials: D
authors.lastname: Hu
authors.affiliation: Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Zhen
authors.identifier: 0000-0001-8037-4245
authors.initials: Z
authors.lastname: Li
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, the Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
authors.forename: Ihab R
authors.initials: IR
authors.lastname: Kamel
mesh_terms: D000368:Aged; D000465:Algorithms; D018207:Angiomyolipoma / Q000000981:diagnostic imaging* / Q000473:pathology; D016477:Artifacts; D015415:Biomarkers; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000473:pathology; D003198:Computer Simulation; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015233:Models, Statistical; D009038:Motion; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers
keywords: angiomyolipoma; clear cell renal cell carcinoma; diffusion-weighted imaging; exponential models