TY - JOUR
T1 - Free-Breathing Liver Fat, R₂* and B₀ Field Mapping Using Multi-Echo Radial FLASH and Regularized Model-Based Reconstruction
AU - Tan, Zhengguo
AU - Unterberg-Buchwald, Christina
AU - Blumenthal, Moritz
AU - Scholand, Nick
AU - Schaten, Philip
AU - Holme, Christian
AU - Wang, Xiaoqing
AU - Raddatz, Dirk
AU - Uecker, Martin
N1 - Publisher Copyright:
© 1982-2012 IEEE.
PY - 2023/5/1
Y1 - 2023/5/1
N2 - This work introduced a stack-of-radial multi-echo asymmetric-echo MRI sequence for free-breathing liver volumetric acquisition. Regularized model-based reconstruction was implemented in Berkeley Advanced Reconstruction Toolbox (BART) to jointly estimate all physical parameter maps (water, fat, R2∗ , and B0 field inhomogeneity maps) and coil sensitivity maps from self-gated κ-space data. Specifically, locally low rank and temporal total variation regularization were employed directly on physical parameter maps. The proposed free-breathing radial technique was tested on a water/fat & iron phantom, a young volunteer, and obesity/diabetes/hepatic steatosis patients. Quantitative fat fraction and R2∗ accuracy were confirmed by comparing our technique with the reference breath-hold Cartesian scan. The multi-echo radial sampling sequence achieves fast κ-space coverage and is robust to motion. Moreover, the proposed motion-resolved model-based reconstruction allows for free-breathing liver fat and R2∗ quantification in multiple motion states. Overall, our proposed technique offers a convenient tool for non-invasive liver assessment with no breath holding requirement.
AB - This work introduced a stack-of-radial multi-echo asymmetric-echo MRI sequence for free-breathing liver volumetric acquisition. Regularized model-based reconstruction was implemented in Berkeley Advanced Reconstruction Toolbox (BART) to jointly estimate all physical parameter maps (water, fat, R2∗ , and B0 field inhomogeneity maps) and coil sensitivity maps from self-gated κ-space data. Specifically, locally low rank and temporal total variation regularization were employed directly on physical parameter maps. The proposed free-breathing radial technique was tested on a water/fat & iron phantom, a young volunteer, and obesity/diabetes/hepatic steatosis patients. Quantitative fat fraction and R2∗ accuracy were confirmed by comparing our technique with the reference breath-hold Cartesian scan. The multi-echo radial sampling sequence achieves fast κ-space coverage and is robust to motion. Moreover, the proposed motion-resolved model-based reconstruction allows for free-breathing liver fat and R2∗ quantification in multiple motion states. Overall, our proposed technique offers a convenient tool for non-invasive liver assessment with no breath holding requirement.
KW - quantitative MRI
KW - model-based reconstruction
KW - Calibration-less compressed sensing parallel imaging
KW - mapping
KW - model-based reconstruction
KW - multi-echo radial sampling
KW - R∗
KW - water/fat separation
UR - http://www.scopus.com/inward/record.url?scp=85144743406&partnerID=8YFLogxK
U2 - 10.1109/TMI.2022.3228075
DO - 10.1109/TMI.2022.3228075
M3 - Article
C2 - 37015368
SN - 0278-0062
VL - 42
SP - 1374
EP - 1387
JO - IEEE Transactions on Medical Imaging
JF - IEEE Transactions on Medical Imaging
IS - 5
ER -