title: On the influence of respiratory motion in radial tissue phase mapping cardiac MRI.
abstract: To investigate the impact of respiratory motion on radial tissue phase mapping (TPM) measurements, and to improve image quality and scan efficiency without compromising velocity fidelity by increasing the respiratory acceptance window with and without motion correction.
  
  
  
  A radial golden angle TPM sequence was measured in 10 healthy volunteers in three short axis slices at 3T. Ungated ( CFREE), self-gated with a single acceptance window ( CREF), motion-corrected averaging using all ( CMCall), or selected ( CMC) data reconstructions were compared by means of various image quality measures and resulting velocities.
  
  
  
  Using all data ( CFREE) resulted in significantly higher perceived signal-to-noise ratio (SNR) (P < 0.001), but significantly reduced sharpness (P < 0.001) and contrast (P = 0.02), when compared to CREF. Coefficient of variation (CV) and perceived sharpness were not significantly different (P > 0.05). With motion-correction, perceived sharpness could be significantly improved ( CMC: P = 0.002; CMCall: P = 0.002) in comparison to CFREE. Velocity peaks of CFREE were significantly reduced compared to CREF (all peaks: P < 0.001; except the longitudinal "E" peak: P = 0.03). The peak velocities in CMC and CMCall were not significantly different from CREF (all peaks: P > 0.08; except longitudinal "E"/"A" peaks: P > 0.01).
  
  
  
  Free-breathing reconstruction results in good perceived image sharpness and velocity information with slightly, but significantly, reduced peak velocities. For achieving velocities and image quality comparable to data from a single acceptance window, but higher gating efficiency, selected motion-corrected TPM (CMC) can be applied. J. Magn. Reson. Imaging 2016;44:1218-1228.
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Germany. jan.paul@uniklinik-ulm.de.
authors.forename: Jan
authors.initials: J
authors.lastname: Paul
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Wundrak
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Germany.
authors.forename: Vinzenz
authors.initials: V
authors.lastname: Hombach
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rottbauer
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Rasche
mesh_terms: D000328:Adult; D016477:Artifacts; D057791:Cardiac Imaging Techniques / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009038:Motion; D012016:Reference Values; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D012680:Sensitivity and Specificity
keywords: cardiac MRI; golden angle; motion-correction; tissue phase mapping (TPM)