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Updated: Jun 18, 2026
Registered Bioimaging of Nanomaterials for Diagnostic and Therapeutic Monitoring
Published on: December 9, 2010
Accelerated multi-b-value multi-shot diffusion-weighted imaging based on EPI with keyhole and a low-rank tensor
Xin Tang1, Juan Gao2, Ahmed Aburas2
1National Engineering Research Center of Advanced Magnetic Resonance Technologies for Diagnosis and Therapy, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China; United Imaging Healthcare Co. Ltd, Shanghai, China.
This study introduces a new calibrationless reconstruction algorithm (SCC-LLRT) to accelerate multi-b-value diffusion-weighted imaging (DWI) using Echo-Planar Imaging with Keyhole (EPIK). The novel method significantly reduces artifacts, improving image quality and mapping accuracy for accelerated DWI scans.
Area of Science:
- Magnetic Resonance Imaging
- Diffusion-Weighted Imaging
- Image Reconstruction
Background:
- Multi-Shot (MS) Echo-Planar Imaging (EPI) enhances in-plane resolution for multi-b-value DWI but increases scan time.
- Accelerating DWI is crucial for clinical applications, requiring advanced imaging and reconstruction techniques.
Purpose of the Study:
- To explore the combination of EPI with Keyhole (EPIK) and a calibrationless reconstruction algorithm for accelerating multi-b-value MS-DWI.
- To develop and validate a novel reconstruction algorithm for EPIK-acquired data.
Main Methods:
- Analyzed the impact of nonuniform phase accrual in EPIK.
- Developed a calibrationless Space-Contrast-Coil Locally Low-Rank Tensor (SCC-LLRT) algorithm for EPIK reconstruction.
- Compared SCC-LLRT with SPA-LLR using simulations, phantoms, and in vivo studies, and compared EPIK with uniformly undersampled EPI in 6 healthy subjects.
Main Results:
- Theoretical analysis and experimental results showed SCC-LLRT reduces aliasing artifacts compared to SPA-LLR.
- EPIK with SCC-LLRT significantly decreased ghosting artifacts compared to uniform undersampled DWI.
- Fitting errors were reduced in ADC (0.05 ± 0.01 vs 0.10 ± 0.01) and IVIM mapping (0.026 ± 0.004 vs 0.06 ± 0.006).
Conclusions:
- The SCC-LLRT algorithm effectively reduces EPIK aliasing artifacts through calibrationless multi-coil data modeling.
- EPIK, combined with SCC-LLRT, offers potential for improved image quality in accelerated multi-b-value MS-DWI.
- Dense k-space center sampling in EPIK contributes to enhanced image quality for accelerated DWI.
