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Dokumenttyp:
Journal Article
Autor(en):
Kronthaler, Sophia; Diefenbach, Maximilian N; Boehm, Christof; Zamskiy, Mark; Makowski, Marcus R; Baum, Thomas; Sollmann, Nico; Karampinos, Dimitrios C
Titel:
On quantification errors of R 2 * $$ {R}_2^{\ast } $$ and proton density fat fraction mapping in trabecularized bone marrow in the static dephasing regime.
Abstract:
PURPOSE: To study the effect of field inhomogeneity distributions in trabecularized bone regions on the gradient echo (GRE) signal with short TEs and to characterize quantification errors on R 2 * $$ {R}_2^{\ast } $$ and proton density fat fraction (PDFF) maps when using a water-fat model with an exponential R 2 * $$ {R}_2^{\ast } $$ decay model at short TEs. METHODS: Field distortions were simulated based on a trabecular bone micro CT dataset. Simulations were performed for different bone volume fractions (BV/TV) and for different bone-fat composition values. A multi-TE UTE acquisition was developed to acquire multiple UTEs with random order to minimize eddy currents. The acquisition was validated in phantoms and applied in vivo in a volunteer's ankle and knee. Chemical shift encoded MRI (CSE-MRI) based on a Cartesian multi-TE GRE scan was acquired in the spine of patients with metastatic bone disease. RESULTS: Simulations showed that signal deviations from the exponential signal decay at short TEs were more prominent for a higher BV/TV. UTE multi-TE measurements reproduced in vivo the simulation-based predicted behavior. In regions with high BV/TV, the presence of field inhomogeneities induced an R 2 * $$ {R}_2^{\ast } $$ underestimation in trabecularized bone marrow when using CSE-MRI at 3T with a short TE. CONCLUSION: R 2 * $$ {R}_2^{\ast } $$ can be underestimated when using short TEs (<2 ms at 3 T) and a water-fat model with an exponential R 2 * $$ {R}_2^{\ast } $$ decay model in multi-echo GRE acquisitions of trabecularized bone marrow.
Zeitschriftentitel:
Magn Reson Med
Jahr:
2022
Band / Volume:
88
Heft / Issue:
3
Seitenangaben Beitrag:
1126-1139
Volltext / DOI:
doi:10.1002/mrm.29279
PubMed:
http://view.ncbi.nlm.nih.gov/pubmed/35481686
Print-ISSN:
0740-3194
TUM Einrichtung:
Institut für Diagnostische und Interventionelle Radiologie (Prof. Makowski); Professur für Neuroradiologie (Prof. Zimmer)
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