title: Comparison of non-Gaussian and Gaussian diffusion models of diffusion weighted imaging of rectal cancer at 3.0 T MRI.
abstract: Water molecular diffusion in vivo tissue is much more complicated. We aimed to compare non-Gaussian diffusion models of diffusion-weighted imaging (DWI) including intra-voxel incoherent motion (IVIM), stretched-exponential model (SEM) and Gaussian diffusion model at 3.0 T MRI in patients with rectal cancer, and to determine the optimal model for investigating the water diffusion properties and characterization of rectal carcinoma. Fifty-nine consecutive patients with pathologically confirmed rectal adenocarcinoma underwent DWI with 16 b-values at a 3.0 T MRI system. DWI signals were fitted to the mono-exponential and non-Gaussian diffusion models (IVIM-mono, IVIM-bi and SEM) on primary tumor and adjacent normal rectal tissue. Parameters of standard apparent diffusion coefficient (ADC), slow- and fast-ADC, fraction of fast ADC (f), α value and distributed diffusion coefficient (DDC) were generated and compared between the tumor and normal tissues. The SEM exhibited the best fitting results of actual DWI signal in rectal cancer and the normal rectal wall (R2= 0.998, 0.999 respectively). The DDC achieved relatively high area under the curve (AUC = 0.980) in differentiating tumor from normal rectal wall. Non-Gaussian diffusion models could assess tissue properties more accurately than the ADC derived Gaussian diffusion model. SEM may be used as a potential optimal model for characterization of rectal cancer.
authors.affiliation: Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China.
authors.forename: Guangwen
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China.
authors.forename: Shuangshuang
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China.
authors.forename: Didi
authors.initials: D
authors.lastname: Wen
authors.affiliation: MR Research China, GE healthcare Greater China, Beijing, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: MR Research China, GE healthcare Greater China, Beijing, P. R. China.
authors.forename: Xiaocheng
authors.initials: X
authors.lastname: Wei
authors.affiliation: Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China.
authors.forename: Wanling
authors.initials: W
authors.lastname: Ma
authors.affiliation: Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Department of Gastrointestinal Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China.
authors.forename: Mian
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Gastrointestinal Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China.
authors.forename: Guosheng
authors.initials: G
authors.lastname: Wu
authors.affiliation: Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012372:ROC Curve; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology