title: Computer-aided detection applied to breast MRI: assessment of CAD-generated enhancement and tumor sizes in breast cancers before and after neoadjuvant chemotherapy.
abstract: OBJECTIVE
  MRI has shown promise in assessing breast cancer patients undergoing neoadjuvant chemotherapy. Computer-aided detection (CAD) for MRI can automatically display tumor enhancement parameters. This study was performed to determine the utility of CAD applied to breast MRI in this patient population.
  
  
  METHODS
  Fifteen patients with 16 newly diagnosed locally advanced breast cancers were evaluated with MRI before and after neoadjuvant chemotherapy. CAD assessments, including presence or absence of significant enhancement, enhancement profiles, and maximum sizes, were recorded. Pre-chemotherapy and post-chemotherapy enhancement profiles were compared. Sizes were compared to those measured by the radiologist and at final pathology.
  
  
  RESULTS
  Prior to chemotherapy, all tumors demonstrated CAD-assessed significant enhancement. Following chemotherapy, 7/16 tumors showed no residual significant enhancement, but all had residual disease at pathology. In those patients with residual enhancement, comparison of the post-chemotherapy to pre-chemotherapy CAD enhancement profiles showed a significant decrease in percentage of washout enhancement (P = 0.0147) in patients with less than 5 mm of residual microscopic disease. Radiologist-measured tumor sizes demonstrated better correlation with sizes at pathology (r = 0.60) than did CAD-generated tumor sizes (r = 0.32).
  
  
  CONCLUSIONS
  CAD may be helpful in assessing changes in MRI enhancement profiles of tumors following chemotherapy. However, CAD-assessed significant enhancement following chemotherapy can be falsely negative for residual malignancy, and CAD tumor sizes are less accurate than those measured by the radiologist in predicting size of residual malignancy. CAD may complement but should not replace the radiologist's assessment of tumors in this patient population.
authors.affiliation: University of Washington Medical Center, University of Washington, Seattle, WA, Seattle Cancer Care Alliance, 825 Eastlake Avenue East, G4-830, Seattle, WA 98109-1023, USA. wdemarti@u.washington.edu
authors.forename: Wendy B
authors.initials: WB
authors.lastname: Demartini
authors.forename: Constance D
authors.initials: CD
authors.lastname: Lehman
authors.forename: Sue
authors.initials: S
authors.lastname: Peacock
authors.forename: Mai T
authors.initials: MT
authors.lastname: Russell
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D017024:Chemotherapy, Adjuvant / Q000379:methods*; D003936:Diagnosis, Computer-Assisted; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D018365:Neoplasm, Residual; D012189:Retrospective Studies