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Optimization of diffusion-weighted single-refocused spin-echo EPI by reducing eddy-current artifacts and shortening
Manoj Shrestha1, Pavel Hok2,3, Ulrike Nöth2
1Brain Imaging Center (BIC), Goethe University Frankfurt, Schleusenweg 2-16, 60528, Frankfurt am Main, Germany. shrestha@med.uni-frankfurt.de.
Magma (New York, N.Y.)
|April 1, 2018
Summary
This study optimized diffusion-weighted single-refocused spin-echo (DW-srSE) imaging without eddy-current compensation (ECC) by using dummy scans. This approach significantly reduced artifacts and improved signal-to-noise ratio (SNR) for better image quality.
Area of Science:
- Magnetic Resonance Imaging
- Diffusion-Weighted Imaging
Background:
- Eddy currents in diffusion-weighted imaging (DWI) can cause artifacts, degrading image quality.
- Traditional intrinsic eddy-current compensation (ECC) in spin-echo sequences can lead to longer echo times (TE) and reduced signal-to-noise ratio (SNR).
Purpose of the Study:
- To optimize diffusion-weighted single-refocused spin-echo (DW-srSE) acquisition without intrinsic ECC.
- To enhance the performance of postprocessing eddy-current compensation (ECC) for improved DWI data.
Main Methods:
- Employed dummy scans with diffusion-weighted gradients to pre-condition eddy currents.
- Optimized parameters for the ECC postprocessing algorithm.
- Compared the proposed method with standard DW-twice-refocused spin-echo (DW-trSE) imaging in vitro and in vivo.
Main Results:
- Simulations demonstrated substantially shorter echo times (TE) with the proposed method compared to intrinsic ECC.
- Acquired data showed a marked increase in signal-to-noise ratio (SNR).
- A minimum dummy scan duration of 1.5 seconds was found to improve ECC postprocessing performance.
Conclusions:
- The optimized DW-srSE sequence and postprocessing ECC algorithm effectively reduced eddy-current artifacts.
- The proposed method offers a higher SNR, leading to improved image quality in DWI.
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