| 1. |
- Ligneul, Clémence, et al.
(författare)
-
Diffusion-weighted MR spectroscopy : Consensus, recommendations, and resources from acquisition to modeling
- 2024
-
Ingår i: Magnetic Resonance in Medicine. - 0740-3194. ; 91:3, s. 860-885
-
Tidskriftsartikel (refereegranskat)abstract
- Brain cell structure and function reflect neurodevelopment, plasticity, and aging; and changes can help flag pathological processes such as neurodegeneration and neuroinflammation. Accurate and quantitative methods to noninvasively disentangle cellular structural features are needed and are a substantial focus of brain research. Diffusion-weighted MRS (dMRS) gives access to diffusion properties of endogenous intracellular brain metabolites that are preferentially located inside specific brain cell populations. Despite its great potential, dMRS remains a challenging technique on all levels: from the data acquisition to the analysis, quantification, modeling, and interpretation of results. These challenges were the motivation behind the organization of the Lorentz Center workshop on “Best Practices & Tools for Diffusion MR Spectroscopy” held in Leiden, the Netherlands, in September 2021. During the workshop, the dMRS community established a set of recommendations to execute robust dMRS studies. This paper provides a description of the steps needed for acquiring, processing, fitting, and modeling dMRS data, and provides links to useful resources.
|
|
| 2. |
- Tapper, Sofie, et al.
(författare)
-
Influence of editing pulse flip angle on J-difference MR spectroscopy
- 2021
-
Ingår i: Magnetic Resonance in Medicine. - : WILEY. - 0740-3194 .- 1522-2594.
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose To investigate the editing-pulse flip angle (FA) dependence of editing efficiency and ultimately to maximize the edited signal of commonly edited MR spectroscopy (MRS) signals, such as gamma-aminobutyric acid (GABA) and lactate. Methods Density-matrix simulations were performed for a range of spin systems to find the editing-pulse FA for maximal editing efficiency. Simulations were confirmed by phantom experiments and in vivo measurements in 10 healthy participants using a 3T Philips scanner. Four MEGA-PRESS in vivo measurements targeting GABA+ and lactate were performed, comparing the conventional editing-pulse FA (FA = 180 degrees) to the optimal one suggested by simulations (FA = 210 degrees). Results Simulations and phantom experiments show that edited GABA and lactate signals are maximal at FA = 210 degrees. Compared to conventional editing (FA = 180 degrees), in vivo signals from GABA+ and lactate signals increase on average by 8.5% and 9.3%, respectively. Conclusion Increasing the FA of editing-pulses in the MEGA-PRESS experiment from 180 degrees to 210 degrees increases the edited signals from GABA+ and lactate by about 9% in vivo.
|
|
