title: [Associations of apparent diffusion coefficient value from MR diffusion-weighted imaging with Ki-67 expression and differentiation grade in gastric cancer].
abstract: OBJECTIVE
  To examine the associations of apparent diffusion coefficient (ADC) value from MR diffusion-weighted imaging (DWI) with Ki-67 expression and differentiation grade in gastric cancer.
  
  
  METHODS
  Images and pathologic data of 68 gastric cancer patients between September 2013 and February 2015 in Affiliated Changshu Hospital of Soochow University were analyzed retrospectively. The expression of Ki-67 antigen in cancer tissue sample was determined by immunohistochemistry. Ki-67 labeling index(LI) was calculated to divide the cases into low Ki-67 group(Ki-67 LI <50%) and high Ki-67 group (Ki-67 LI ≥ 50%). Associations of ADC value with differentiation grade and Ki-67 LI were examined.
  
  
  RESULTS
  Mean ADC value of low Ki-67 LI group was significantly higher than that of high Ki-67 LI group [(0.977 ± 0.100) × 10(-3) mm(2)/s vs. (0.859 ± 0.064) × 10(-3) mm(2)/s, P=0.000]. The ADC value was negatively correlated with Ki-67 LI (r=-0.685, P=0.000). Mean ADC value of well differentiated adenocarcinoma, moderately differentiated adenocarcinoma, poorly differentiated adenocarcinoma, and signet-ring cell carcinoma was (1.124 ± 0.080) × 10(-3) mm(2)/s, (0.950 ± 0.064) × 10(-3) mm(2)/s, (0.899 ± 0.091) × 10(-3) mm(2)/s, and (0.894 ± 0.081) × 10(-3) mm(2)/s respectively. Difference of ADC value among differentiation grades was significantly different (F=11.405, P=0.000). Difference of ADC value between well differentiated adenocarcinoma and non-well differentiated adenocarcinoma was significantly different(P=0.000).
  
  
  CONCLUSIONS
  ADC value is associated with differentiation grade and Ki-67 LI of gastric cancer, which may be used as a noninvasive predictor for evaluating the proliferation and differentiation grade of gastric cancer.
authors.affiliation: Department of Radiology, Affiliated Changshu Hospital, Soochow University, Jiangsu Changshu 215500, China.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Lu
authors.affiliation: Department of Radiology, Affiliated Changshu Hospital, Soochow University, Jiangsu Changshu 215500, China.
authors.forename: Honghuan
authors.initials: H
authors.lastname: Yao
authors.affiliation: Department of Radiology, Affiliated Changshu Hospital, Soochow University, Jiangsu Changshu 215500, China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Radiology, Affiliated Changshu Hospital, Soochow University, Jiangsu Changshu 215500, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Radiology, Affiliated Changshu Hospital, Soochow University, Jiangsu Changshu 215500, China.
authors.forename: Libiao
authors.initials: L
authors.lastname: Ji
authors.affiliation: Department of Radiology, Affiliated Changshu Hospital, Soochow University, Jiangsu Changshu 215500, China.
authors.forename: Weixin
authors.initials: W
authors.lastname: Qian
authors.affiliation: Department of Pathology, The First Affiliated Hospital, Soochow University, Suzhou 215006, China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Gu
authors.affiliation: Medical Imaging Center, The First Affiliated Hospital, Soochow University, Suzhou 215006, China. hch5305@163.com.
authors.forename: Chunhong
authors.initials: C
authors.lastname: Hu
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis*; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000175:diagnosis*
chemical_list: D019394:Ki-67 Antigen