title: [Application of apparent diffusion coefficient ratio in the diagnosis of bladder cancer grading pre-operation].
abstract: OBJECTIVE
  To explore the value of apparent diffusion coefficient (ADC) ratio in the diagnosis of bladder cancer pre-operation by analyzing its differences among different grades of bladder cancer.
  
  
  METHODS
  A total of 52 cases of bladder cancer were all definitely diagnosed with histological results.Routine examinations of magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) were performed preoperatively on each patient. ADC map was constructed in work station and ADC values of tumor and internal obturator muscle were measured (b = 800 s/mm(2)).Ratio of ADC was calculated with internal obturator muscle as reference site. Then the relationship between ADC ratio and bladder cancer grade was analyzed.
  
  
  RESULTS
  Mean ratio of ADC of all tumors was 0.98±0.35, G1 (1.12±0.21) and G2 (0.67±0.29), the sensitivity and specificity of ADC ratio was 90.2% and 85.3% respectively with an optimal threshold of 0.96. The ratios of ADC of low-grade group were significantly higher than those of high-grade group while the values of non-muscle-invasive group were significantly higher than those of muscle-invasive group. The ratios of ADC of tumor were inversely associated with the malignancy degree of bladder cancer (r = -0.845, P < 0.05).
  
  
  CONCLUSIONS
  The ratio of ADC of bladder cancer reflects the lesion tissue properties. And its measurement plays an important role in the diagnosis of bladder cancer grading pre-operation.
authors.affiliation: Department of Radiology, Affiliated Oriental Hospital, Tongji University, Shanghai 200120 China.
authors.forename: Guo-xing
authors.initials: GX
authors.lastname: Zhou
authors.forename: Yi-bin
authors.initials: YB
authors.lastname: Wang
authors.affiliation: Email: frank-hao@hotmail.com.
authors.forename: Nan-xin
authors.initials: NX
authors.lastname: Hao
authors.forename: Ying-wei
authors.initials: YW
authors.lastname: Wu
authors.forename: Jing-qi
authors.initials: JQ
authors.lastname: Zhu
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.forename: Zhong-qiu
authors.initials: ZQ
authors.lastname: Wang
authors.affiliation: Department of Radiology, Shanghai Ninth People's Hospital Affiliated Shanghai JiaoTong University School of Medicine, Shanghai 200011,Email:cjr.taoxiaofeng @ hotmail.com.
authors.forename: Xiao-feng
authors.initials: XF
authors.lastname: Tao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000473:pathology*