title: Observer variability and applicability of BI-RADS terminology for breast MR imaging: invasive carcinomas as focal masses.
abstract: OBJECTIVE
  The purpose of this study was to assess whether the descriptive terminology and final assessment categories of the Breast Imaging Reporting and Data System (BI-RADS) lexicon can be used for breast carcinomas detected on MR imaging and to assess the inter- and intraobserver variabilities in the use of the descriptors and final assessment categories.
  
  
  METHODS
  In 82 patients, 101 masses, including 68 infiltrating carcinomas and 33 benign lesions, were interpreted independently by four radiologists and described by BI-RADS terminology with respect to mass shape and margin and BI-RADS final assessment categories. The enhancement pattern of the mass was also reported. In addition, two radiologists interpreted each case twice to evaluate intraobserver variability. The final case set for analysis was the 68 infiltrating carcinomas.
  
  
  RESULTS
  Most of the infiltrating carcinomas were described as irregular, spiculated, and heterogeneously enhancing masses. The final impression of the 68 carcinomas was BI-RADS category 5 (highly suggestive of malignancy) in 41 (61%), category 4 (suspicious abnormality) in 24 (35%), and category 3 (probably benign) in three (4%). Enhancement pattern was heterogeneous in 40 (59%), homogeneous in 14 (21%), and rim in 14 (21%). Interobserver agreement was moderate for mass margin, shape, enhancement, and final assessment category.
  
  
  CONCLUSIONS
  This study suggests that the mammographic BI-RADS lexicon with some modifications may be applied to describe the features of infiltrating carcinoma seen on breast MR imaging.
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, Cornell University Medical College, 1275 York Ave., New York, NY 10021, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Kim
authors.forename: E A
authors.initials: EA
authors.lastname: Morris
authors.forename: L
authors.initials: L
authors.lastname: Liberman
authors.forename: D J
authors.initials: DJ
authors.lastname: Ballon
authors.forename: L R
authors.initials: LR
authors.lastname: La Trenta
authors.forename: O
authors.initials: O
authors.lastname: Hadar
authors.forename: A
authors.initials: A
authors.lastname: Abramson
authors.forename: D D
authors.initials: DD
authors.lastname: Dershaw
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000145:classification / Q000175:diagnosis* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000145:classification / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D005348:Fibrocystic Breast Disease / Q000145:classification / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009367:Neoplasm Staging; D012680:Sensitivity and Specificity; D009626:Terminology as Topic