title: Features of Undiagnosed Breast Cancers at Screening Breast MR Imaging and Potential Utility of Computer-Aided Evaluation.
abstract: OBJECTIVE
  To retrospectively evaluate the features of undiagnosed breast cancers on prior screening breast magnetic resonance (MR) images in patients who were subsequently diagnosed with breast cancer, as well as the potential utility of MR-computer-aided evaluation (CAE).
  
  
  METHODS
  Between March 2004 and May 2013, of the 72 consecutive pairs of prior negative MR images and subsequent MR images with diagnosed cancers (median interval, 32.8 months; range, 5.4-104.6 months), 36 (50%) had visible findings (mean size, 1.0 cm; range, 0.3-5.2 cm). The visible findings were divided into either actionable or underthreshold groups by the blinded review by 5 radiologists. MR imaging features, reasons for missed cancer, and MR-CAE features according to actionability were evaluated.
  
  
  RESULTS
  Of the 36 visible findings on prior MR images, 33.3% (12 of 36) of the lesions were determined to be actionable and 66.7% (24 of 36) were underthreshold; 85.7% (6 of 7) of masses and 31.6% (6 of 19) of non-mass enhancements were classified as actionable lesions. Mimicking physiologic enhancements (27.8%, 10 of 36) and small lesion size (27.8%, 10 of 36) were the most common reasons for missed cancer. Actionable findings tended to show more washout or plateau kinetic patterns on MR-CAE than underthreshold findings, as the 100% of actionable findings and 46.7% of underthreshold findings showed washout or plateau (p = 0.008).
  
  
  CONCLUSIONS
  MR-CAE has the potential for reducing the number of undiagnosed breast cancers on screening breast MR images, the majority of which are caused by mimicking physiologic enhancements or small lesion size.
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.; Department of Radiology, Chung-Ang University Hospital, Seoul 06973, Korea.
authors.forename: Mirinae
authors.initials: M
authors.lastname: Seo
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.; Department of Radiology, Seoul National College of Medicine, Seoul 03080, Korea.; Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 03080, Korea.
authors.forename: Nariya
authors.initials: N
authors.lastname: Cho
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.
authors.forename: Min Sun
authors.initials: MS
authors.lastname: Bae
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.; Department of Radiology, Hanyang University College of Medicine, Seoul 04763, Korea.
authors.forename: Hye Ryoung
authors.initials: HR
authors.lastname: Koo
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.
authors.forename: Won Hwa
authors.initials: WH
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.
authors.forename: Su Hyun
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.; Department of Radiology, SMG-SNU Boramae Medical Center, Seoul 07061, Korea.
authors.forename: Ajung
authors.initials: A
authors.lastname: Chu
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008327:Mammography / Q000379:methods*; D008875:Middle Aged; D012189:Retrospective Studies
keywords: Computer-aided evaluation; False negative breast cancer; Magnetic resonance imaging