title: Does the degree of background enhancement in breast MRI affect the detection and staging of breast cancer?
abstract: OBJECTIVE
  The purpose of this study was to assess the influence of background enhancement on the detection and staging of breast cancer using MRI as an adjunct to mammography or ultrasound.
  
  
  METHODS
  One hundred forty-six bilateral breast MRI examinations were evaluated to assess the extent of a known primary tumour and to problem solve after mammography or ultrasound without adjusting for the phase in the patients' menstrual cycle. The background enhancement was classified into four categories by visual evaluation: minimal, mild, moderate and marked.
  
  
  RESULTS
  In total, 131 histologically confirmed abnormal cases (104 malignant and 27 benign) and 15 normal cases were included in the analysis. There was no tumour size-related bias between the groups (p = 0.522). For the primary index tumour, the sensitivities of MRI with minimal/mild and moderate/marked background enhancement were 100% and 76% (p = 0.001), respectively. Thus, the degree of background enhancement did not affect the specificity. For evaluating tumour extent (n = 104), the accuracy of MRI with moderate/marked background enhancement (52%) was significantly lower than that with minimal/mild background enhancement (84%; p = 0.002).
  
  
  CONCLUSIONS
  The degree of background enhancement affected the detection and staging of breast cancer using MRI.
authors.affiliation: Breast Imaging and Breast Intervention Section, Shizuoka Cancer Center Hospital, Naga-izumi, Shizuoka 411-8777, Japan. t.uematsu@scchr.jp
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Uematsu
authors.forename: Masako
authors.initials: M
authors.lastname: Kasami
authors.forename: Junichiro
authors.initials: J
authors.lastname: Watanabe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008327:Mammography / Q000379:methods; D008495:Medical Oncology / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000379:methods