1. Assessing potential correlation between T 2 relaxation and diffusion of lactate in the mouse brain
- Author
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Eloïse Mougel, Sophie Malaquin, Julien Valette, Laboratoire des Maladies Neurodégénératives - UMR 9199 (LMN), Service MIRCEN (MIRCEN), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie François JACOB (JACOB), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie François JACOB (JACOB), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
intracellular/extracellular ,lactate ,[SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging ,apparent diffusivity ,compartmentation ,T2 relaxation ,Radiology, Nuclear Medicine and imaging ,apparent kurtosis ,DW-MRS ,frequency-selective sequence - Abstract
International audience; While diffusion and T 2 relaxation are intertwined, little or no correlation exists between diffusion and T 2 relaxation of intracellular metabolites in the rodent brain, as measured by diffusion-weighted MRS at different TEs. However, situation might be different for lactate, since it is present in both extracellular and intracellular spaces, which exhibit different diffusion properties and may also exhibit different T 2. Such a TE dependence would be crucial to account for when interpreting or modeling lactate diffusion. Here we propose to take advantage of a new diffusion sequence, where J-modulation of lactate is canceled even at long TE, thus retaining excellent signal, to assess potential T 2 dependence on diffusion of lactate in the mouse brain. Methods: Using a frequency-selective diffusion-weighted spin-echo sequence that removes J-modulation at 1.3 ppm, thus preserving lactate signal even at long TE, we investigate the effect of TE between 50.9 and 110.9 ms (while keeping diffusion time constant) on apparent diffusivity and kurtosis in the mouse brain. Results: Regardless of the metabolites, no difference appears for the diffusion-weighted signal attenuation with increasing TE. For lactate, apparent diffusivity and kurtosis remain unchanged as TE increases. Conclusion: No significant TE dependence of diffusivity and kurtosis is measured for lactate in the 50-110 ms TE range, confirming that potential T 2 effects can be ignored when interpreting or modeling lactate diffusion.
- Published
- 2022