title: Accuracy of 3 T versus 1.5 T breast MRI for pre-operative assessment of extent of disease in newly diagnosed DCIS.
abstract: OBJECTIVE
  While 3T breast magnetic resonance imaging has increased in use over the past decade, there is little data comparing its use for assessing ductal carcinoma in situ (DCIS) versus 1.5 T. We sought to compare the accuracies of DCIS extent of disease measures on pre-operative 3T versus 1.5 T MRI.
  
  
  METHODS
  This institutional review board-approved prospective study included 20 patients with ductal carcinoma in situ diagnosed by core needle biopsy (CNB) who underwent pre-operative breast MRI at both 3T (resolution=0.5 mm×0.5 mm×1.3 mm) and 1.5 T (0.85 mm×0.85 mm×1.6 mm). All patients provided informed consent, and the study was HIPPA compliant. Lesion sizes and imaging characteristics (morphologic and kinetic enhancement) were recorded for the 3 T and 1.5 T examinations. Lesion size measures at both field strengths were correlated to final pathology, and imaging characteristics also were compared.
  
  
  RESULTS
  Of the initial cohort of 20 patients with CNB-diagnosed DCIS, 19 underwent definitive surgery. Median DCIS sizes of these 19 patients were 6mm (range: 0-67 mm) on 3T, 13 mm (0-60 mm) on 1.5 T, and 6mm (0-55 mm) on surgical pathology. Size correlation between MRI and pathology was higher for 3T (Spearman's ρ=0.66, p=0.002) than 1.5 T (ρ=0.36, p=0.13). In 10 women in which a residual area of suspicious enhancement was identified on both field strengths, there was agreement of morphologic description (NME vs. mass) in nine, and no significant difference in dynamic contrast enhanced kinetics at 3T compared to 1.5 T.
  
  
  CONCLUSIONS
  Pre-operative breast MRI at 3T provided higher correlation with final pathology size of DCIS lesions compared to 1.5 T, and may be more accurate for assessment of disease extent prior to definitive surgery.
authors.affiliation: University of Washington School of Medicine, Seattle Cancer Care Alliance, Department of Radiology, Breast Imaging Section, 825 Eastlake Avenue East, Seattle, WA 98109-1023, USA. Electronic address: hrahbar@uw.edu.
authors.forename: Habib
authors.initials: H
authors.lastname: Rahbar
authors.affiliation: University of Washington School of Medicine, Seattle Cancer Care Alliance, Department of Radiology, Breast Imaging Section, 825 Eastlake Avenue East, Seattle, WA 98109-1023, USA.
authors.forename: Wendy B
authors.initials: WB
authors.lastname: DeMartini
authors.affiliation: University of Washington School of Medicine, Seattle Cancer Care Alliance, Department of Radiology, Breast Imaging Section, 825 Eastlake Avenue East, Seattle, WA 98109-1023, USA.
authors.forename: Amie Y
authors.initials: AY
authors.lastname: Lee
authors.affiliation: University of Washington School of Medicine, Seattle Cancer Care Alliance, Department of Radiology, Breast Imaging Section, 825 Eastlake Avenue East, Seattle, WA 98109-1023, USA.
authors.forename: Savannah C
authors.initials: SC
authors.lastname: Partridge
authors.affiliation: University of Washington School of Medicine, Seattle Cancer Care Alliance, Department of Radiology, Breast Imaging Section, 825 Eastlake Avenue East, Seattle, WA 98109-1023, USA.
authors.forename: Sue
authors.initials: S
authors.lastname: Peacock
authors.affiliation: University of Washington School of Medicine, Seattle Cancer Care Alliance, Department of Radiology, Breast Imaging Section, 825 Eastlake Avenue East, Seattle, WA 98109-1023, USA.
authors.forename: Constance D
authors.initials: CD
authors.lastname: Lehman
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011300:Preoperative Care; D011446:Prospective Studies; D015203:Reproducibility of Results
keywords: 3T; Breast MRI; Ductal carcinoma in situ; Pre-operative