title: Investigation of the non-Gaussian water diffusion properties in bladder cancer using diffusion kurtosis imaging: a preliminary study.
abstract: OBJECTIVE
  The objective of this study was to investigate the non-Gaussian water diffusion properties in bladder cancer and assess the efficacy of diffusion kurtosis imaging for estimating the histological grade of bladder cancer.
  
  
  METHODS
  Twenty-one patients with bladder cancer (high-grade, 12; low-grade, 9) and 17 negative controls who underwent preoperative 3.0-T magnetic resonance imaging including multi-b value diffusion-weighted imaging (b values, 0, 500, 800, 1200, 1500, and 2000 s/mm) were included. Besides apparent diffusion coefficient (ADC) maps, diffusion kurtosis imaging maps for diffusion coefficient (Dapp) and kurtosis (Kapp) were also obtained. Data were analyzed using the Mann-Whitney U test, Spearman correlation test, and receiver operating characteristic curves.
  
  
  RESULTS
  Bladder cancer showed significantly lower ADC values, lower Dapp values, and higher Kapp values compared with normal bladder wall (all P < 0.001). The Kapp values were significantly higher in high-grade than in low-grade tumors (P = 0.007). Significant correlations were found between Dapp and ADC (r = 0.901, P < 0001) as well as between Kapp and ADC (r = -0.910, P <0.001). The areas under the receiver operating characteristic curve were 0.843 and 0.796 for estimation of high-grade bladder cancer by using the Kapp values and ADC values, respectively.
  
  
  CONCLUSIONS
  Diffusion in bladder cancer follows a non-Gaussian behavior. The new metric Kapp may potentially serve as a biomarker of grade of bladder cancer.
authors.affiliation: From the *Department of Radiology, Ren Ji Hospital, School of Medicine, and †School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Shiteng
authors.initials: S
authors.lastname: Suo
authors.forename: Xiaoxi
authors.initials: X
authors.lastname: Chen
authors.forename: Xiang
authors.initials: X
authors.lastname: Ji
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Zhuang
authors.forename: Lianming
authors.initials: L
authors.lastname: Wu
authors.forename: Qiuying
authors.initials: Q
authors.lastname: Yao
authors.forename: Yu
authors.initials: Y
authors.lastname: Fan
authors.forename: Jianrong
authors.initials: J
authors.lastname: Xu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016011:Normal Distribution; D001749:Urinary Bladder Neoplasms / Q000473:pathology*; D014867:Water
chemical_list: D014867:Water