Exploiting gradient-echo frequency evolution: Probing white matter microstructure and extracting bulk susceptibility-induced frequency for quantitative susceptibility mapping.
Magn Reson Med
; 91(4): 1676-1693, 2024 Apr.
Article
en En
| MEDLINE
| ID: mdl-38102838
ABSTRACT
PURPOSE:
This work is to investigate the microstructure-induced frequency shift in white matter (WM) with crossing fibers and to separate the microstructure-related frequency shift from the bulk susceptibility-induced frequency shift by model fitting the gradient-echo (GRE) frequency evolution for potentially more accurate quantitative susceptibility mapping (QSM).METHODS:
A hollow-cylinder fiber model (HCFM) with two fiber populations was developed to investigate GRE frequency evolutions in WM voxels with microstructural orientation dispersion. The simulated and experimentally measured TE-dependent local frequency shift was then fitted to a simplified frequency evolution model to obtain a microstructure-related frequency difference parameter ( ∆ f $$ \Delta f $$ ) and a TE-independent bulk susceptibility-induced frequency shift ( C f $$ {C}_f $$ ). The obtained C f $$ {C}_f $$ was then used for QSM reconstruction. Reconstruction performances were evaluated using a numerical head phantom and in vivo data and then compared to other multi-echo combination methods.RESULTS:
GRE frequency evolutions and ∆ f $$ \Delta f $$ -based tissue parameters in both parallel and crossing fibers determined from our simulations were comparable to those observed in vivo. The TE-dependent frequency fitting method outperformed other multi-echo combination methods in estimating C f $$ {C}_f $$ in simulations. The fitted ∆ f $$ \Delta f $$ , C f $$ {C}_f $$ , and QSM could be improved further by navigator-based B0 fluctuation correction.CONCLUSION:
A HCFM with two fiber populations can be used to characterize microstructure-induced frequency shifts in WM regions with crossing fibers. HCFM-based TE-dependent frequency fitting provides tissue contrast related to microstructure ( ∆ f $$ \Delta f $$ ) and in addition may help improve the quantification accuracy of C f $$ {C}_f $$ and the corresponding QSM.Palabras clave
Texto completo:
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Bases de datos:
MEDLINE
Asunto principal:
Sustancia Blanca
Idioma:
En
Revista:
Magn Reson Med
/
Magn. Reson. Med
/
Magnetic Resonance in Medicine
Asunto de la revista:
DIAGNOSTICO POR IMAGEM
Año:
2024
Tipo del documento:
Article
País de afiliación:
Estados Unidos