Interleaved diffusion-weighted improved by adaptive partial-Fourier and multiband multiplexed sensitivity-encoding reconstruction

Abstract

Purpose We report a series of techniques to reliably eliminate artifacts in interleaved echo-planar imaging (EPI) based diffusion weighted imaging (DWI). Methods First, we integrate the previously reported multiplexed sensitivity encoding (MUSE) algorithm with a new adaptive Homodyne partial-Fourier reconstruction algorithm, so that images reconstructed from interleaved partial-Fourier DWI data are free from artifacts even in the presence of either a) motion-induced k-space energy peak displacement, or b) susceptibility field gradient induced fast phase changes. Second, we generalize the previously reported single-band MUSE framework to multi-band MUSE, so that both through-plane and in-plane aliasing artifacts in multi-band multi-shot interleaved DWI data can be effectively eliminated. Results The new adaptive Homodyne-MUSE reconstruction algorithm reliably produces high-quality and high-resolution DWI, eliminating residual artifacts in images reconstructed with previously reported methods. Furthermore, the generalized MUSE algorithm is compatible with multi-band and high-throughput DWI. Conclusion The integration of the multi-band and adaptive Homodyne-MUSE algorithms significantly improves the spatial-resolution, image quality, and scan throughput of interleaved DWI. We expect that the reported reconstruction framework will play an important role in enabling high-resolution DWI for both neuroscience research and clinical uses.

Human brain diffusion tensor imaging at submillimeter isotropic resolution on a 3 Tesla clinical MRI scanner

“…As shown in recent papers, 2D MUSE was designed to estimate shot-to-shot phase variations directly from interleaved EPI data without relying on navigator echoes (Chang et al, 2014; Chen et al, 2013; Chu et al, 2014). However, for 3D interleaved EPI, navigator signals with zero k z encoding are needed (Figure 1), because the shot-to-shot phase variations cannot be inherently estimated from weak DWI signals at high k z planes.…”

The future of image-guided radiotherapy will be MR guided

“…MR-gRT solutions are being made rapidly to overcome the obstacles associated with MR-only workflows encompassing QA devices, novel dose calculation algorithms that can account for magnetic field dose perturbances, fast automated contouring algorithms and imaging protocols for intrafraction motion monitoring and plan adaptation. 61,77,84,85 Another potential solution to the issue of cost-effectiveness of this technology would be to determine if the addition of off-line MRI simulations might improve the accuracy of current day IGRT while improving patient throughput on MR-gRT systems.…”

“…It is to be noted that recent developments such as multiplexed sensitivity encoding and simultaneous multislice potentially provide sufficient spatial resolution to be used for real-time image guidance. 61,62 The ability of magnetic spectroscopy imaging (MRS) to diagnose areas of high metabolic activity linked to tumour cell proliferation is particularly useful for RT treatment planning because of better gross tumour volume delineation. 27 MRS can also help during image guidance by daily tumour imaging facilitating simultaneous integrated boost treatments.…”

Joint multi-shot multi-channel image reconstruction in compressive diffusion weighted MR imaging

“…Recently, alternating methods applying PI techniques were introduced. 4, 16,17 In, 4 author showed that when the number of shots is between 2 to 4, GRAPPA is superior to SENSE in the sense of immunity to motion while SENSE has slightly higher SNR. In 16 and, 17 author introduced a reconstruction scheme for MS-EPI based on SENSE.…”