Hao Peng1,2, Liwen Wan1, Qian Wan1, Jianxun Lv1, Chuanli Cheng1, Yi Wang3, Wenzhong Liu2, Xin Liu1, Hairong Zheng1, and Chao Zou1
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology,Chinese Academy of Sciences, Shenzhen, China, 2Key Laboratory of Imaging Processing and Intelligence Control, School of Artificial Intelligence and Automation, Huazhong University of Science & Technology, Wuhan, China, 3Department of Radiology, Peking University Peoples Hospital, Beijing, China
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology,Chinese Academy of Sciences, Shenzhen, China, 2Key Laboratory of Imaging Processing and Intelligence Control, School of Artificial Intelligence and Automation, Huazhong University of Science & Technology, Wuhan, China, 3Department of Radiology, Peking University Peoples Hospital, Beijing, China
In
our work, we explored the effects of flip angle on aliased phasor solution in DIXON model, and verified a fat-water separation approach incorporated with prior T1 information. Combined with acceleration techniques, proposed method could cover whole liver within a single breath-hold.
FIGURE
2. Flowchart of the proposed algorithm. a: Multi-echo gradient echo images with different flip angles; b: candidate phasor solution classification; c-d:
Pixels were then classified into “smooth” and “non-smooth” and the “smooth”
pixels were grouped into different sub-regions according to the spatial
connectivity; e:Phasor solution of each sub-region were determined using dual
flip angle prior information and combined as in f. g: Fat water components under different FA, and water components under different
FAs could be used for further T1 quantification.
FIGURE
3 Timing diagram of the pulse sequence. The sequence consists of three blocks.
A: B1+ mapping block based on DREAM for T1 mapping (Optional). B & C:
multiple echo GRE with 3D acquisition using k-space linear reordering under
different FAs. The equally spaced echoes are acquired with monopolar readout
mode. The echo spacing (∆TE) are kept the same in B and C, but the echo times
of C are moved shTE to B. The pre-dephasing gradients indicated by the blue
trapezoids have the same amplitudes and ramp-up time. For simplicity, the slice
selection and phase encoding gradients are omitted.