title: Can signal enhancement ratio (SER) reduce the number of recommended biopsies without affecting cancer yield in occult MRI-detected lesions?
abstract: OBJECTIVE
  We retrospectively determined if signal enhancement ratio (SER), a quantitative measure of contrast kinetics using volumetric parameters, could reduce the number of biopsy recommendations without decreasing the number of cancers detected when applied to suspicious lesions seen on breast magnetic resonance imaging (MRI).
  
  
  METHODS
  A retrospective review of Breast Imaging Reporting and Data System (BIRADS) 4 or 5 lesions seen on breast MRI in 2008 that were clinically and mammographically occult yielded a final sample size of 73 lesions in 65 patients. Images were processed with in-house software. Parameters used to predict benignity/malignancy included SER total tumor volume (lesion volume above a 70% initial enhancement level), SER partial tumor volume (volume with "washout" and "plateau" kinetics), SER washout tumor volume, peak SER, and peak percent enhancement. Thresholds were determined to retrospectively discriminate benign from malignant histopathology. Clinical impact was assessed through the reduction in the number of biopsies recommended (by eliminating benign lesions discriminated by SER).
  
  
  RESULTS
  Based on the original radiologist interpretations, 73 occult lesions were called suspicious and biopsied with a predictive value of biopsies (PPV(3)) of 18/73 (25%). SER parameters were found to be significantly associated with histopathology (P < .05). Biopsy recommendations could be reduced using SER parameters of SER partial tumor volume (73 to 40), SER total tumor volume (73 to 45), and peak percent enhancement (73 to 55) without removing true positives.
  
  
  CONCLUSIONS
  The adjunctive use of SER parameters may reduce the number of recommended biopsies without reducing the number of cancers detected.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, 94115, USA.
authors.forename: Vignesh A
authors.initials: VA
authors.lastname: Arasu
authors.forename: Ryan C-Y
authors.initials: RC
authors.lastname: Chen
authors.forename: David N
authors.initials: DN
authors.lastname: Newitt
authors.forename: C Belinda
authors.initials: CB
authors.lastname: Chang
authors.forename: Hilda
authors.initials: H
authors.lastname: Tso
authors.forename: Nola M
authors.initials: NM
authors.lastname: Hylton
authors.forename: Bonnie N
authors.initials: BN
authors.lastname: Joe
mesh_terms: D001706:Biopsy; D001943:Breast Neoplasms / Q000175:diagnosis*; D003287:Contrast Media / Q000493:pharmacokinetics*; D005260:Female; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA