title: In vitro validation of phase-contrast flow measurements at 3 T in comparison to 1.5 T: precision, accuracy, and signal-to-noise ratios.
abstract: OBJECTIVE
  To evaluate the signal-to-noise ratio (SNR), precision, and accuracy of phase-contrast flow measurements at 3 T with the help of an in vitro model and to compare the results with data from two 1.5-T scanners.
  
  
  METHODS
  Using an identical setup of a laminar flow model and sequence parameters, measurements were done at one 3-T and at two 1.5-T systems. Precision, accuracy, and SNR were obtained for velocity encodings ranging from 55 up to 550 cm(-1). SNRs were calculated from the magnitude as well as the flow encoded images.
  
  
  RESULTS
  Precision and accuracy for the in vitro flow model were similarly high in all scanners with no significant difference. For velocity encodings from 55 cm(-1) up to 550 cm(-1), the SNR in magnitude as well as phase encoded images of the 3-T measurements was approximately 2.5 times higher than the SNR obtained from the two 1.5-T systems.
  
  
  CONCLUSIONS
  Even without optimization for the 3-T environment, flow measurements show the same high accuracy and precision as is known from clinical 1.5-T scanners. The superior SNR at 3 T will allow further improvements in temporal and spatial resolution. This will be of interest for small-size vessels like coronary arteries or for slow diastolic flow patterns.
authors.affiliation: Department of Diagnostic Radiology, Hannover Medical School, 30625 Hannover, Germany. lotz.joachim@mh-hannover.de
authors.forename: Joachim
authors.initials: J
authors.lastname: Lotz
authors.forename: Rolf
authors.initials: R
authors.lastname: Döker
authors.forename: Ralph
authors.initials: R
authors.lastname: Noeske
authors.forename: Meike
authors.initials: M
authors.lastname: Schüttert
authors.forename: Roland
authors.initials: R
authors.lastname: Felix
authors.forename: Michael
authors.initials: M
authors.lastname: Galanski
authors.forename: Matthias
authors.initials: M
authors.lastname: Gutberlet
authors.forename: Gerd Peter
authors.initials: GP
authors.lastname: Meyer
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology*; D066298:In Vitro Techniques; D018810:Magnetic Resonance Angiography / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results