Technical Note: Clustering‐based motion compensation scheme for multishot diffusion tensor imaging

Abstract

Purpose To extend image reconstruction using image‐space sampling function (IRIS) to address large‐scale motion in multishot diffusion‐weighted imaging (DWI). Methods A clustered IRIS (CIRIS) algorithm that would extend IRIS was proposed to correct for large‐scale motion. For DWI, CIRIS initially groups the shots into clusters without intracluster large‐scale motion and reconstructs each cluster by using IRIS. Then, CIRIS registers these cluster images and combines the registered images by using a weighted average to correct for voxel mismatch caused by intercluster large‐scale motion. For diffusion tensor imaging (DTI), CIRIS further reduces the effect of motion on diffusion directions by treating motion‐induced direction changes as additional diffusion directions. CIRIS also introduces the detection and rejection of motion‐corrupted data to avoid corresponding image degradation. The proposed method was evaluated by simulation and in vivo diffusion datasets. Results Experiments demonstrated that CIRIS can reduce motion‐induced blurring and artifacts in DWI and provide more accurate DTI estimations in the presence of large‐scale motion, compared with IRIS. Conclusion The proposed method presents a novel approach to correct for large‐scale in‐plane motion for multishot DWI and is expected to benefit the practical application of high‐resolution diffusion imaging.

3D‐EPI blip‐up/down acquisition (BUDA) with CAIPI and joint Hankel structured low‐rank reconstruction for rapid distortion‐free high‐resolution T2* mapping

“…Shot‐selective 2D CAIPIRINHA can also be exploited to further push the limits of acceleration and resolution 46 . Furthermore, a clustering‐based motion correction approach can be introduced to improve motion robustness 15 . Deep learning approaches can also be investigated to enhance image quality and enable higher accelerations 53–59 …”

“…7,10 To mitigate the geometric distortions present in EPI, a range of correction approaches has been developed. 5,6,[11][12][13][14][15][16][17][18] A common approach is to improve the acceleration factor along the phase encoding direction with the aid of parallel imaging to mitigate distortion. [19][20][21][22][23] However, as the acceleration factor increases, the g-factor penalty and under-sampling-associated artifacts may become severe.…”

MRI: Evaluating the Application of FOCUS‐MUSE Diffusion‐Weighted Imaging in the Pancreas in Comparison With FOCUS, MUSE, and Single‐Shot DWIs

“…16 Another multishot DWI sequence (multiplexed sensitivity-encoding DWI [MUSE DWI] in GE, readout-segmented echo-planar [RESOLVE] in Siemens, and image reconstruction using image-space sampling function [IRIS] in Philips) has been applied to evaluate diseases in various organs, such as liver, breast, and central nervous system with a better SNR. [17][18][19] In theory, FOCUS combined with MUSE can yield a better image quality and SNR than FOCUS and MUSE technique. However, its clinical application is unclear.…”

“…Nevertheless, SNR of rFOV DWI can be reduced 16 . Another multishot DWI sequence (multiplexed sensitivity‐encoding DWI [MUSE DWI] in GE, readout‐segmented echo‐planar [RESOLVE] in Siemens, and image reconstruction using image‐space sampling function [IRIS] in Philips) has been applied to evaluate diseases in various organs, such as liver, breast, and central nervous system with a better SNR 17–19 …”

Diffusion‐weighted magnetic resonance imaging in rat kidney using two‐dimensional navigated, interleaved echo‐planar imaging at 7.0 T

“…[13][14][15] Multishot EPI (ms-EPI) is an alternative approach to improve the geometric fidelity of DWI. This technique distributes the acquisition of the k-space data across multiple shots, each covering a dedicated k-space segment along the frequency-encoding (readout-segmented ms-EPI) 16 or the phase-encoding (interleaved ms-EPI) 17,18 direction. Interleaved ms-EPI effectively increases the bandwidth along the phase-encoding direction and thus reduces geometric distortion.…”