title: Apparent diffusion coefficient of diffusion weighted MRI in endometrial carcinoma-Relationship with local invasiveness.
abstract: OBJECTIVE
  To evaluate the relationship between apparent diffusion coefficient (ADC) value and the local invasiveness of endometrial carcinoma.
  
  
  METHODS
  The MR imaging of seventy-three patients with endometrial carcinoma proved by post-operative pathology and sixty-four patients with healthy uteri were retrospectively reviewed. All MR examinations included axial T2WI and T1WI, sagittal T2WI and diffusion-weighted sequences (b=0 and b=1000s/mm(2)). Tumor size, mean ADC value (ADCm) and quartile ADC (ADCq) were acquired on post-processing workstation using voxel-analysis software. Differences between the ADC values among three layers of normal uterine body and endometrial carcinomas were compared by ANOVA test. Groups were divided according to pathologic type, histologic grade, depth of myometrial infiltration, presence of cervical invasion and lymphovascular space invasion, and lymph node metastasis. Tumor size and ADC values were compared and analyzed.
  
  
  RESULTS
  ADC values were different in three zones of uterine body (P<0.001), with the lowest in junctional zone [(1.126±0.190)×10(-3)mm(2)/s] and highest in outer myometrium [(1.496±0.196)×10(-3)mm(2)/s]. Mean ADC value of endometrial carcinomas [(1.011±0.121)×10(-3)mm(2)/s] was lower than the normal uterine body. Quartile ADC and tumor size were greater in groups with more invasive pathologic factors (P<0.05). Deep myometrial infiltration, cervical invasion, lymphovascular space invasion and lymph node metastasis were more common as quartile ADC values and tumor sizes increased.
  
  
  CONCLUSIONS
  Mean ADC value was lower in endometrial carcinoma was lower than the normal uterus. Quartile ADC, representing the intra-tumor heterogeneity of water movement, had a profound relationship with invasiveness of endometrial carcinomas, while mean ADC value did not. ADC values may serve as a quantitative indicator to complement routine sequences.
authors: Department of Radiology, Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University Cancer Hospital & Institute, 52# Fucheng Road, Haidian District, Beijing 100142, China. kun-cao@hotmail.com
authors: Kun
authors: K
authors: Cao
authors: Min
authors: M
authors: Gao
authors: Ying-Shi
authors: YS
authors: Sun
authors: Yan-Ling
authors: YL
authors: Li
authors: Yu
authors: Y
authors: Sun
authors: Yu-Nong
authors: YN
authors: Gao
authors: Xiao-Peng
authors: XP
authors: Zhang