Correction for acceleration-induced displacement artifacts in phase contrast imaging.
The acceleration-induced displacement artifact impairs the accuracy of MR velocity measurements. This study proposes a post processing method for correction of this artifact. Velocity measurements were performed in a flow phantom containing a constriction. Velocity curves were obtained from streamlines parallel to the frequency, phase, and slice directions, respectively. The acceleration-induced displacement artifact was most prominent when the frequency encoding direction was aligned with the flow direction. After correction, velocity assignment improved and a more accurate description of the flow was obtained. In vivo measurements were performed in the aorta in a patient with a repaired aortic coarctation. The correction method was applied to velocity data along a streamline parallel to the frequency encoding direction. The result after correction was a new location of the peak velocity and improved estimates of the velocity gradients.
Thunberg
P
P
Department of Biomedical Engineering, Linköping University, Linköping, Sweden. perth@imt.liu.se
Wigström
L
L
Wranne
B
B
Engvall
J
J
Karlsson
M
M
D000328:Adult; D000465:Algorithms; D001013:Aorta, Thoracic / Q000473:pathology; D016477:Artifacts; D001783:Blood Flow Velocity; D003251:Constriction, Pathologic; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008961:Models, Structural