TY - JOUR
T1 - Comparison of centric and reverse-centric trajectories for highly accelerated three-dimensional saturation recovery cardiac perfusion imaging
AU - Wang, Haonan
AU - Bangerter, Neal K.
AU - Park, Daniel J.
AU - Adluru, Ganesh
AU - Kholmovski, Eugene G.
AU - Xu, Jian
AU - DiBella, Edward
N1 - Publisher Copyright:
© 2014 Wiley Periodicals, Inc.
PY - 2015/10/1
Y1 - 2015/10/1
N2 - Purpose Highly undersampled three-dimensional (3D) saturation-recovery sequences are affected by k-space trajectory since the magnetization does not reach steady state during the acquisition and the slab excitation profile yields different flip angles in different slices. This study compares centric and reverse-centric 3D cardiac perfusion imaging. Methods An undersampled (98 phase encodes) 3D ECG-gated saturation-recovery sequence that alternates centric and reverse-centric acquisitions each time frame was used to image phantoms and in vivo subjects. Flip angle variation across the slices was measured, and contrast with each trajectory was analyzed via Bloch simulation. Results Significant variations in flip angle were observed across slices, leading to larger signal variation across slices for the centric acquisition. In simulation, severe transient artifacts were observed when using the centric trajectory with higher flip angles, placing practical limits on the maximum flip angle used. The reverse-centric trajectory provided less contrast, but was more robust to flip angle variations. Conclusion Both of the k-space trajectories can provide reasonable image quality. The centric trajectory can have higher CNR, but is more sensitive to flip angle variation. The reverse-centric trajectory is more robust to flip angle variation.
AB - Purpose Highly undersampled three-dimensional (3D) saturation-recovery sequences are affected by k-space trajectory since the magnetization does not reach steady state during the acquisition and the slab excitation profile yields different flip angles in different slices. This study compares centric and reverse-centric 3D cardiac perfusion imaging. Methods An undersampled (98 phase encodes) 3D ECG-gated saturation-recovery sequence that alternates centric and reverse-centric acquisitions each time frame was used to image phantoms and in vivo subjects. Flip angle variation across the slices was measured, and contrast with each trajectory was analyzed via Bloch simulation. Results Significant variations in flip angle were observed across slices, leading to larger signal variation across slices for the centric acquisition. In simulation, severe transient artifacts were observed when using the centric trajectory with higher flip angles, placing practical limits on the maximum flip angle used. The reverse-centric trajectory provided less contrast, but was more robust to flip angle variations. Conclusion Both of the k-space trajectories can provide reasonable image quality. The centric trajectory can have higher CNR, but is more sensitive to flip angle variation. The reverse-centric trajectory is more robust to flip angle variation.
KW - 3D cardiac perfusion
KW - compressed sensing
KW - k-space trajectory
UR - http://www.scopus.com/inward/record.url?scp=84941915932&partnerID=8YFLogxK
U2 - 10.1002/mrm.25478
DO - 10.1002/mrm.25478
M3 - Article
C2 - 25285855
AN - SCOPUS:84941915932
SN - 0740-3194
VL - 74
SP - 1070
EP - 1076
JO - Magnetic Resonance in Medicine
JF - Magnetic Resonance in Medicine
IS - 4
ER -