title: Clinical application of the BI-RADS final assessment to breast sonography in conjunction with mammography.
abstract: OBJECTIVE
  The objective of our study was to report the results of classification of sonographic findings according to BI-RADS and to calculate the positive predictive value (PPV) for each BI-RADS assessment category.
  
  
  METHODS
  We prospectively classified 4,668 breast sonograms according to BI-RADS final assessment category. Suspicious sonographic findings were divided into major and minor suspicious findings. Category 1 was normal and category 2 was a benign finding such as cyst or nodule with uniform and intense hyperechogenicity. A nodule neither category 2 nor category 4 or 5 was defined as category 3. A nodule with one or more suspicious findings, not category 5, was defined as category 4. A nodule with two or more major suspicious findings was defined as category 5.
  
  
  RESULTS
  Of the 4,668 cases, 321 cases failed to undergo follow-up of at least 1 year. The PPV was 0.1% in category 1 (3/2,191), 0% in category 2 (0/773), 0.8% in category 3 (6/737), 31.1% in category 4 (161/519), and 96.9% in category 5 (123/127). In palpable lesions (n = 751), the PPV was 2.2% in category 1 (2/93), 0.9% in category 3 (2/217), 54% in category 4 (107/198), and 98% in category 5 (98/100). In nonpalpable lesions (n = 3,596), the PPV was 0.05% in category 1 (1/2,098), 0.8% in category 3 (4/520), 16.8% in category 4 (54/321), and 92.6% in category 5 (25/27).
  
  
  CONCLUSIONS
  As with mammography, placing sonographic lesions into BI-RADS categories is useful for predicting the presence of malignancy.
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, 134, Shinchon-dong, Seodaemun-gu, Seoul 120-752, South Korea. ekkim@yuhs.ac
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
authors.forename: Kyung Hee
authors.initials: KH
authors.lastname: Ko
authors.forename: Ki Keun
authors.initials: KK
authors.lastname: Oh
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Kwak
authors.forename: Jai Kyung
authors.initials: JK
authors.lastname: You
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Kim
authors.forename: Byoung-Woo
authors.initials: BW
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000145:classification* / Q000000981:diagnostic imaging*; D002277:Carcinoma / Q000145:classification* / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008327:Mammography; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D016217:Ultrasonography, Mammary