title: Accelerated phase-contrast MR imaging: comparison of k-t BLAST with SENSE and Doppler ultrasound for velocity and flow measurements in the aorta.
abstract: OBJECTIVE
  To evaluate differences in velocity and flow measurements in the aorta between accelerated phase-contrast (PC) magnetic resonance imaging (MRI) using SENSE and k-t BLAST and in peak velocity to Doppler ultrasound.
  
  
  METHODS
  Two-dimensional PC-MRI perpendicular to the ascending and descending aorta was performed in 11 volunteers using SENSE (R = 2) and k-t BLAST (2-, 4-, 6-, and 8-fold). Peak velocity, mean velocity, and stroke volume of the accelerated PC-MRI experiments were correlated. Peak velocities were compared to Doppler ultrasound.
  
  
  RESULTS
  All acceleration techniques showed significant correlations for peak velocity with Doppler ultrasound. However, k-t BLAST 6 and 8 showed a significant underestimation. Strong correlations between SENSE and k-t BLAST were found for all three parameters. Significant differences in peak velocity were found between SENSE and all k-t BLAST experiments, but not for 2-fold k-t BLAST in the ascending aorta, and 2- and 4-fold k-t BLAST in the descending aorta. For mean velocity no significant differences were found. Stroke volume showed significant differences for all k-t BLAST experiments in the ascending and for 6- and 8-fold k-t BLAST in the descending aorta.
  
  
  CONCLUSIONS
  Peak velocity of accelerated PC-MRI correlated with CW Doppler measurements, but high k-t BLAST acceleration factors lead to a significant underestimation. SENSE with R = 2 and 2-fold k-t BLAST are most highly correlated in phase-contrast flow measurements.
authors.affiliation: MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Stadlbauer
authors.forename: Wilma
authors.initials: W
authors.lastname: van der Riet
authors.forename: Sebastian
authors.initials: S
authors.lastname: Globits
authors.forename: Gerard
authors.initials: G
authors.lastname: Crelier
authors.forename: Erich
authors.initials: E
authors.lastname: Salomonowitz
mesh_terms: D000293:Adolescent; D000328:Adult; D001011:Aorta / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology*; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric