title: Correlations between apparent diffusion coefficient values of invasive ductal carcinoma and pathologic factors on diffusion-weighted MRI at 3.0 Tesla.
abstract: OBJECTIVE
  To investigate correlations between apparent diffusion coefficient (ADC) values of invasive ductal carcinoma (IDC) and pathologic factors on diffusion-weighted MRI. We measured the ADC values of IDC of the breast and analyzed correlations between ADC values and factors such as tumor size, axillary lymph node status, histologic grade, estrogen receptor, progesterone receptor, and human epithelial growth factor 2 (HER2) using diffusion-weighted MRI at 3.0 Tesla (T).
  
  
  METHODS
  We examined 110 patients with pathologically confirmed IDC using diffusion-weighted MRI at 3.0T. The ADC values of breast cancer were calculated using two b factors (0 and 1000 s/mm(2)). The relationship between ADC values and tumor size, histologic grade, axillary lymph node status, hormonal receptors, and HER2 were analyzed.
  
  
  RESULTS
  The mean ADC value of IDC (n = 110) was 0.88 ± 0.15 × 10(-2) mm(2)/s. Tumors were subgrouped according to size (<2 cm, 2-5 cm, and ≥5 cm). Multiple comparisons within subgroups according to size showed that the ADC values for the three tumor size groups were significantly different (correlation coefficient = -0.007). The mean apparent diffusion coefficient of HER2-positive IDC was significantly higher than that of HER2-negative invasive ductal carcinoma (correlation coefficient = 0.218).
  
  
  CONCLUSIONS
  ADC values of IDC were significantly correlated with tumor size and HER2 status.
authors.affiliation: Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Park
authors.forename: Hye-Young
authors.initials: HY
authors.lastname: Choi
authors.forename: Soo Yeon
authors.initials: SY
authors.lastname: Hahn
mesh_terms: D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008875:Middle Aged; D012189:Retrospective Studies; D047368:Tumor Burden
keywords: ADC value; breast cancer; diffusion weighted image; invasive ductal carcinoma; magnetic resonance imaging