Yuheng Huang1,2, Xinheng Zhang1,2, Serry Fradad1, Lu Meng1, Ghazal Yoosefian1, Linda Azab1, Xinqi Li3, Alan Kwan4, Rohan Dharmakumar1, Hui Han1, and Hsin-Jung Yang1
1Biomedical Imaging Research Institute, Cedars Sinai Medical Center, Los Angeles, CA, United States, 2Bioengineering, UCLA, Los Angeles, CA, United States, 3Columbia University, New York, NY, United States, 4Cardiology, Cedars Sinai Medical Center, Los Angeles, CA, United States
1Biomedical Imaging Research Institute, Cedars Sinai Medical Center, Los Angeles, CA, United States, 2Bioengineering, UCLA, Los Angeles, CA, United States, 3Columbia University, New York, NY, United States, 4Cardiology, Cedars Sinai Medical Center, Los Angeles, CA, United States
An accurate and reliable
phase mapping algorithm with Ultra-High dynamic range was developed using a multi-echo
GRE sequence with uneven echo spacing and iterative reconstruction.
Figure 1. Image processing flow chart and the
uneven echo spacing. The image processing pipeline is presented in panel A. Phase
images were first combined with a graph-cut algorithm to conduct high SNR phase
maps. The central frequency and unwrapping artifact were further calibrated
from the derivative of the phase difference maps between the uneven DTEs. The phase accumulation from the uneven
echo spacing is presented in panel B.
Figure 5. In-vivo images from a healthy human volunteer with an ICD on the chest. In the presents of ICD, the compromised image SNR and strong phase accumulation
from the off-resonance source lead to obvious phase unwrapping artifacts and
central frequency shifts in the peer algorithms (arrows). The proposed AUTO-HDR
shows a much smoother field map around the ICD and higher SNR at a region
further away from the ICD. The improved field map demonstrates the capability
of AUTO-HDR in resolving fast varying phase change while preserving high SNR in
human subjects with metallic implants.
