title: Breast cancer detected on an incident (second or subsequent) round of screening MRI: MRI features of false-negative cases.
abstract: OBJECTIVE
  The purpose of this article is to evaluate the nature of breast cancers detected in the incident round of screening MRI to determine MRI features of early breast cancer.
  
  
  METHODS
  From 2003 to 2012, there were 16 incident breast cancers in 15 patients on screening MRI, including nine cancers that were retrospectively identifiable on the prior MRI (false-negative [FN] cancers at prior screening examination). We evaluated the BI-RADS features of these incident cancers in previous and current MRI scans.
  
  
  RESULTS
  Of 16 incident cancers, there were 11 mass lesions (69%), three foci (19%), and two nonmasslike enhancement lesions (13%). Of the nine FN cancers (five foci, two masses, and two nonmasslike enhancement lesions), all showed increases in size on the current examination (median, 80% increase); four lesions showed rapid uptake kinetics on prior examinations, and five lesions showed a change in kinetic pattern from slow to rapid uptake. Among the five foci, one focus was isolated and four foci were in a background of other foci, where two foci could be distinguished for their higher signal intensity.
  
  
  CONCLUSIONS
  On screening MRI, any lesion that increases in size, has rapid uptake kinetics or a change in kinetic pattern, or is an isolated focus or focus showing more enhancement than other foci should be viewed with a high degree of suspicion, and a biopsy should be considered.
authors.affiliation: 1 Department of Radiology, University of Chicago, Chicago, IL.
authors.forename: Ken
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: David
authors.initials: D
authors.lastname: Schacht
authors.forename: Gillian M
authors.initials: GM
authors.lastname: Newstead
authors.forename: Angela R
authors.initials: AR
authors.lastname: Bradbury
authors.forename: Marion S
authors.initials: MS
authors.lastname: Verp
authors.forename: Olufunmilayo I
authors.initials: OI
authors.lastname: Olopade
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Abe
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D003287:Contrast Media; D005188:False Negative Reactions; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D033162:Incidental Findings; D008279:Magnetic Resonance Imaging / Q000379:methods*; D053783:Magnetic Resonance Imaging, Interventional; D008403:Mass Screening; D008875:Middle Aged; D012189:Retrospective Studies; D018084:Ultrasonography, Interventional
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA