title: The value of diffusion-weighted imaging in assessing the ADC changes of tissues adjacent to breast carcinoma.
abstract: BACKGROUND
  To define a threshold value of apparent diffusion coefficient (ADC) with which malignant breast lesions can be distinguished from benign lesions, and to evaluate the ADC change of peri-tumor tissue in breast carcinoma by echo planar-diffusion weighted imaging (EPI-DWI).
  
  
  METHODS
  57 breast lesions were scanned by routine MRI and EPI-DWI. The ADC values were compared between malignant and benign lesions. The sensitivity and specificity of EPI-DWI and the threshold ADC value were evaluated by Receiver Operating Characteristic curve (ROC). The ADC values of malignant lesion and layered peri-tumor tissues (from innermost layer 1 to outermost layer 4 with 5 mm every layer) in different directions were compared and the ADC values among different layers were compared.
  
  
  RESULTS
  The ADC value of 35 malignant lesions was statistically lower than that of 22 benign lesions (P < 0.05). In ROC curve, the threshold value was 1.24 +/- 0.25*10E-3 mm(2)/s (b = 500) or 1.20 +/- 0.25*10E-3 mm(2)/s (b = 1000). The ADC value of malignant lesions was statistically lower than that of peri-tumor tissues in different directions (P < 0.05). For peri-tumor tissues, the ADC values increased gradually from layer 1 to layer 4 and there was a significant difference between the ADC values of layer 1 and layer 2 (P < 0.05); while from layer 2 outwards, there was no statistical difference among different layers.
  
  
  CONCLUSIONS
  ADC value was a sensitive and specific parameter that could help to differentiate benign and malignant breast lesions. ADC changes in tissues adjacent to breast carcinoma could be detected by EPI-DWI, which made EPI-DWI a promising method for helping to determine surgical scope of breast carcinoma.
authors.affiliation: Imaging Center, the 1st Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, PR China. yilishengli@hotmail.com
authors.forename: Zhang
authors.initials: Z
authors.lastname: Yili
authors.forename: Huang
authors.initials: H
authors.lastname: Xiaoyan
authors.forename: Du
authors.initials: D
authors.lastname: Hongwen
authors.forename: Zhang
authors.initials: Z
authors.lastname: Yun
authors.forename: Chen
authors.initials: C
authors.lastname: Xin
authors.forename: Wang
authors.initials: W
authors.lastname: Peng
authors.forename: Guo
authors.initials: G
authors.lastname: Youmin
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000473:pathology; D001941:Breast Diseases / Q000175:diagnosis* / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis / Q000473:pathology; D003937:Diagnosis, Differential; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D018226:Fibroadenoma / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D006965:Hyperplasia; D008875:Middle Aged