Title | Free-breathing fat and R * quantification in the liver using a stack-of-stars multi-echo acquisition with respiratory-resolved model-based reconstruction. |
Publication Type | Journal Article |
Year of Publication | 2020 |
Authors | Schneider M, Benkert T, Solomon E, Nickel D, Fenchel M, Kiefer B, Maier A, Chandarana H, Block KTobias |
Journal | Magn Reson Med |
Volume | 84 |
Issue | 5 |
Pagination | 2592-2605 |
Date Published | 2020 11 |
ISSN | 1522-2594 |
Keywords | Breath Holding, Humans, Liver, Magnetic Resonance Imaging, Non-alcoholic Fatty Liver Disease, Respiration |
Abstract | PURPOSE: To develop a free-breathing hepatic fat and quantification method by extending a previously described stack-of-stars model-based fat-water separation technique with additional modeling of the transverse relaxation rate . METHODS: The proposed technique combines motion-robust radial sampling using a stack-of-stars bipolar multi-echo 3D GRE acquisition with iterative model-based fat-water separation. Parallel-Imaging and Compressed-Sensing principles are incorporated through modeling of the coil-sensitivity profiles and enforcement of total-variation (TV) sparsity on estimated water, fat, and parameter maps. Water and fat signals are used to estimate the confounder-corrected proton-density fat fraction (PDFF). Two strategies for handling respiratory motion are described: motion-averaged and motion-resolved reconstruction. Both techniques were evaluated in patients (n = 14) undergoing a hepatobiliary research protocol at 3T. PDFF and parameter maps were compared to a breath-holding Cartesian reference approach. RESULTS: Linear regression analyses demonstrated strong (r > 0.96) and significant (P ≪ .01) correlations between radial and Cartesian PDFF measurements for both the motion-averaged reconstruction (slope: 0.90; intercept: 0.07%) and the motion-resolved reconstruction (slope: 0.90; intercept: 0.11%). The motion-averaged technique overestimated hepatic values (slope: 0.35; intercept: 30.2 1/s) compared to the Cartesian reference. However, performing a respiratory-resolved reconstruction led to better value consistency (slope: 0.77; intercept: 7.5 1/s). CONCLUSIONS: The proposed techniques are promising alternatives to conventional Cartesian imaging for fat and quantification in patients with limited breath-holding capabilities. For accurate estimation, respiratory-resolved reconstruction should be used. |
DOI | 10.1002/mrm.28280 |
Alternate Journal | Magn Reson Med |
PubMed ID | 32301168 |
PubMed Central ID | PMC7396291 |
Grant List | P41 EB017183 / EB / NIBIB NIH HHS / United States R01 EB018308 / EB / NIBIB NIH HHS / United States |
Related Institute:
MRI Research Institute (MRIRI)