AI Article Synopsis
- The study compares the effectiveness of multi-echo (ME) and time-division multiplexing (TDM) sequences in accelerated relaxation-diffusion MRI (rdMRI) for accurate microstructure measurements.
- TDM produced results closely matching the reference single-echo (SE) sequences with minimal errors, while ME sequences showed higher biases in both phantom and in-vivo tests.
- Overall, TDM proved to be a more reliable method for estimating relaxation-diffusion parameters while speeding up MRI acquisition times by 2 to 3 times.
Article Abstract
Purpose: To compare the performance of multi-echo (ME) and time-division multiplexing (TDM) sequences for accelerated relaxation-diffusion MRI (rdMRI) acquisition and to examine their reliability in estimating accurate rdMRI microstructure measures.
Method: The ME, TDM, and the reference single-echo (SE) sequences with six TEs were implemented using Pulseq with single-band (SB) and multi-band 2 (MB2) acceleration factors. On a diffusion phantom, the image intensities of the three sequences were compared, and the differences were quantified using the normalized RMS error (NRMSE). Shinnar-Le Roux (SLR) pulses were implemented for the SB-ME and SB-SE sequences to investigate the impact of slice profiles on ME sequences. For the in-vivo brain scan, besides the image intensity comparison and T-estimates, different methods were used to assess sequence-related effects on microstructure estimation, including the relaxation diffusion imaging moment (REDIM) and the maximum-entropy relaxation diffusion distribution (MaxEnt-RDD).
Results: TDM performance was similar to the gold standard SE acquisition, whereas ME showed greater biases (3-4× larger NRMSEs for phantom, 2× for in-vivo). T values obtained from TDM closely matched SE, whereas ME sequences underestimated the T relaxation time. TDM provided similar diffusion and relaxation parameters as SE using REDIM, whereas SB-ME exhibited a 60% larger bias in the
Conclusion: Our analysis demonstrates that TDM provides a more accurate estimation of relaxation-diffusion measurements while accelerating the acquisitions by a factor of 2 to 3.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11436305 | PMC |
| http://dx.doi.org/10.1002/mrm.30246 | DOI Listing |
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