title: Phase contrast MRI with flow compensation view sharing.
abstract: OBJECTIVE
  To develop and evaluate a technique for accelerating phase contrast MRI (PC-MRI) acquisitions without significant compromise in flow quantification accuracy.
  
  
  METHODS
  PC-MRI is commonly acquired using interleaved flow-compensated (FC) and flow-encoded (FE) echoes. We hypothesized that FC data, which represent background phase, do not change significantly over time. Therefore, we proposed to undersample the FC data and use an FC view sharing (FCVS) approach to synthesize a composite FC frame for each corresponding FE frame. FCVS was evaluated in a flow phantom and healthy volunteers and compared with a standard FC/FE PC-MRI.
  
  
  RESULTS
  The FCVS sequence resulted in an error of 0.0% for forward flow and 2.0% for reverse flow volume when compared with FC/FE PC-MRI in a flow phantom. Measurements in the common carotid arteries showed that the FCVS method had -1.16 cm/s bias for maximum peak velocity and -0.019 mL bias in total flow, when compared with FC/FE with the same temporal resolution, but double the total acquisition time. These results represent ≤1.3% bias error in velocity and volumetric flow quantification.
  
  
  CONCLUSIONS
  FCVS can accelerate PC-MRI acquisitions while maintaining flow and velocity measurement accuracy when there is limited temporal variation in the FC data.
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA; Biomedical Physics Interdepartmental Graduate Program, University of California, Los Angeles, Los Angeles, California, USA.
authors.forename: Da
authors.initials: D
authors.lastname: Wang
authors.forename: Jiaxin
authors.initials: J
authors.lastname: Shao
authors.forename: Stanislas
authors.initials: S
authors.lastname: Rapacchi
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Middione
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Ennis
authors.forename: Peng
authors.initials: P
authors.lastname: Hu
mesh_terms: D000465:Algorithms; D016477:Artifacts; D001783:Blood Flow Velocity / Q000502:physiology*; D017536:Carotid Artery, Common / Q000033:anatomy & histology / Q000502:physiology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: flow quantification; flow rate; phase contrast MRI; temporal footprint; temporal resolution; velocity encoding; view sharing