Accuracy and reproducibility in phase contrast imaging using SENSE.
The purpose of this study was to evaluate the accuracy and reproducibility of phase contrast imaging using the sensitivity encoding (SENSE) method at different reduction factors. Analytical expressions were derived that state how reproducibility is influenced for velocity and flow measurements. Computer simulations, and in vitro and in vivo studies were performed in order to validate these expressions and to assess how accuracy is affected when different reduction factors are applied. It was shown that reproducibility depends on the reduction and geometry factors. Since the geometry factor varies spatially, so does the reproducibility for phase contrast imaging. In areas with high geometry factors, the standard deviation (SD) may become so large that aliasing occurs. The accuracy of phase contrast imaging is not influenced directly when SENSE is used, but may be indirectly influenced due to high SDs of the measured phase that may subsequently cause aliasing. The current results show that it is possible to achieve accurate flow measurements even at high reduction factors. By taking the geometry factor into account, it may be possible to find areas where phase contrast imaging is accurate even at high reduction factors.
Thunberg
Per
P
Department of Biomedical Engineering, Orebro University Hospital, Orebro, Sweden. per.thunberg@orebroll.se
Karlsson
Matts
M
Wigström
Lars
L
D001783:Blood Flow Velocity; D003198:Computer Simulation; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted