title: Phase-contrast MRI with hybrid one and two-sided flow-encoding and velocity spectrum separation.
abstract: To develop and evaluate a phase-contrast MRI (PC-MRI) technique with hybrid one and two-sided flow-encoding and velocity spectrum separation (HOTSPA) for accelerated blood flow and velocity measurement.
  
  
  
  In the HOTSPA technique, the two-sided flow encoding (FE) is used for two FE directions and one-sided is used for the remaining FE direction. Such a temporal modulation of the FE strategy allows for separations of the Fourier velocity spectrum into components for the flow-compensated and the three-directional velocity waveforms, accelerating PC-MRI by encoding three-directional velocities using only two repetition times (TRs) instead of four TRs as in standard PC-MRI. The HOTSPA was evaluated and compared with standard PC-MRI in the common carotid arteries of six healthy volunteers.
  
  
  
  Total volumetric flow and peak velocity measurements based on HOTSPA and the conventional PC-MRI were in good agreement with a bias of -0.005 mL (-0.1% relative bias error) for total volumetric flow and 1.21 cm/s (1.1% relative bias error) for peak velocity, although the total acquisition time was 50% of the conventional PC-MRI.
  
  
  
  The proposed HOTSPA technique achieved nearly two-fold acceleration of PC-MRI while maintaining accuracy for total volumetric flow and peak velocity quantification by separating the paired acquisitions in the Fourier velocity spectrum domain. Magn Reson Med 78:182-192, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors: Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.|Biomedical Physics Interdepartmental Graduate Program, University of California, Los Angeles, California, USA.
authors: Da
authors: D
authors: Wang
authors: Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
authors: Jiaxin
authors: J
authors: Shao
authors: Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.|Biomedical Physics Interdepartmental Graduate Program, University of California, Los Angeles, California, USA.|Department of Bioengineering, University of California, Los Angeles, California, USA.
authors: Daniel B
authors: DB
authors: Ennis
authors: Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.|Biomedical Physics Interdepartmental Graduate Program, University of California, Los Angeles, California, USA.
authors: Peng
authors: 0000-0002-0719-1159
authors: P
authors: Hu
mesh_terms: D000328:Adult; D000465:Algorithms; D001783:Blood Flow Velocity / Q000502:physiology*; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
keywords: 4D-flow; phase contrast MRI; temporal modulation