title: A novel approach to contrast-enhanced breast magnetic resonance imaging for screening: high-resolution ultrafast dynamic imaging.
abstract: OBJECTIVE
  The use of breast magnetic resonance imaging (MRI) as screening tool has been stalled by high examination costs. Scan protocols have lengthened to optimize specificity. Modern view-sharing sequences now enable ultrafast dynamic whole-breast MRI, allowing much shorter and more cost-effective procedures. This study evaluates whether dynamic information from ultrafast breast MRI can be used to replace standard dynamic information to preserve accuracy.
  
  
  METHODS
  We interleaved 20 ultrafast time-resolved angiography with stochastic trajectory (TWIST) acquisitions (0.9 × 1 × 2.5 mm, temporal resolution, 4.3 seconds) during contrast inflow in a regular high-resolution dynamic MRI protocol. A total of 160 consecutive patients with 199 enhancing abnormalities (95 benign and 104 malignant) were included. The maximum slope of the relative enhancement versus time curve (MS) obtained from the TWIST and curve type obtained from the regular dynamic sequence as defined in the breast imaging reporting and data system (BIRADS) lexicon were recorded. Diagnostic performance was compared using receiver operating characteristic analysis.
  
  
  RESULTS
  All lesions were visible on both the TWIST and standard series. Maximum slope allows discrimination between benign and malignant disease with high accuracy (area under the curve, 0.829). Types of MS were defined in analogy to BIRADS curve types: MS type 3 implies a high risk of malignancy (MS >13.3%/s; specificity, 85%), MS type 2 yields intermediate risk (MS <13.3%/s and >6.4%/s), and MS type 1 implies a low risk (MS <6.4%/s; sensitivity, 90%). This simplification provides a much higher accuracy than the much lengthier BIRADS curve type analysis does (area under the curve, 0.812 vs 0.692; P = 0.0061).
  
  
  CONCLUSIONS
  Ultrafast dynamic breast MRI allows detection of breast lesions and classification with high accuracy using MS. This allows substantial shortening of scan protocols and hence reduces imaging costs, which is beneficial especially for screening.
authors.affiliation: From the *Radboud University Nijmegen Medical Centre, Department of Radiology, Nijmegen, the Netherlands; †Siemens Medical Solutions, New York, NY; and ‡FraunHofer MEVIS, Bremen, Germany.
authors.forename: Ritse M
authors.initials: RM
authors.lastname: Mann
authors.forename: Roel D
authors.initials: RD
authors.lastname: Mus
authors.forename: Jan
authors.initials: J
authors.lastname: van Zelst
authors.forename: Christian
authors.initials: C
authors.lastname: Geppert
authors.forename: Nico
authors.initials: N
authors.lastname: Karssemeijer
authors.forename: Bram
authors.initials: B
authors.lastname: Platel
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis*; D003287:Contrast Media; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media