title: Simultaneous multi-slice readout-segmented echo planar imaging for accelerated diffusion-weighted imaging of the breast.
abstract: OBJECTIVE
  Readout-segmented echo planar imaging (rs-EPI) significantly reduces susceptibility artifacts in diffusion-weighted imaging (DWI) of the breast compared to single-shot EPI but is limited by longer scan times. To compensate for this, we tested a new simultaneous multi-slice (SMS) acquisition for accelerated rs-EPI.
  
  
  METHODS
  After approval by the local ethics committee, eight healthy female volunteers (age, 38.9 ± 13.1 years) underwent breast MRI at 3T. Conventional as well as two-fold (2× SMS) and three-fold (3× SMS) slice-accelerated rs-EPI sequences were acquired at b-values of 50 and 800 s/mm(2). Two independent readers analyzed the apparent diffusion coefficient (ADC) in fibroglandular breast parenchyma. The signal-to-noise ratio (SNR) was estimated based on the subtraction method. ADC and SNR were compared between sequences by using the Friedman test.
  
  
  RESULTS
  The acquisition time was 4:21 min for conventional rs-EPI, 2:35 min for 2× SMS rs-EPI and 1:44 min for 3× SMS rs-EPI. ADC values were similar in all sequences (mean values 1.62 × 10(-3)mm(2)/s, p=0.99). Mean SNR was 27.7-29.6, and no significant differences were found among the sequences (p=0.83).
  
  
  CONCLUSIONS
  SMS rs-EPI yields similar ADC values and SNR compared to conventional rs-EPI at markedly reduced scan time. Thus, SMS excitation increases the clinical applicability of rs-EPI for DWI of the breast.
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland. Electronic address: Lukas.Filli@usz.ch.
authors.forename: Lukas
authors.initials: L
authors.lastname: Filli
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland.
authors.forename: Soleen
authors.initials: S
authors.lastname: Ghafoor
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Kenkel
authors.affiliation: Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: MR Application Development, Siemens Healthcare, Erlangen, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Weiland
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland.
authors.forename: Gustav
authors.initials: G
authors.lastname: Andreisek
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Frauenfelder
authors.affiliation: Inselspital, Universitätsinstitut für Diagnostische, Interventionelle und Pädiatrische Radiologie, Bern, Switzerland.
authors.forename: Val M
authors.initials: VM
authors.lastname: Runge
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Boss
mesh_terms: D000328:Adult; D016477:Artifacts; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D013382:Subtraction Technique
keywords: Blipped CAIPIRINHA; Breast; Diffusion-weighted imaging; Readout-segmented echo planar imaging; Simultaneous multi-slice