Related Experiment Videos
Simultaneous phase correction and SENSE reconstruction for navigated multi-shot DWI with non-cartesian k-space
Chunlei Liu1, Michael E Moseley, Roland Bammer
1Lucas MRS/I Center, Department of Radiology, Stanford University, Stanford, CA 94305-5488, USA.
Magnetic Resonance in Medicine
|November 9, 2005
Summary
This study introduces a novel iterative reconstruction algorithm to correct motion-induced phase errors in multi-shot diffusion-weighted imaging (DWI). The method effectively integrates with Sensitivity Encoding (SENSE) for improved image quality.
Area of Science:
- Magnetic Resonance Imaging
- Medical Imaging
- Image Reconstruction
Background:
- Diffusion-weighted imaging (DWI) utilizes phase-navigated multi-shot acquisition and parallel imaging (like SENSE) to reduce distortions and enhance spatial resolution.
- Applying parallel imaging methods, such as SENSE, to multi-shot DWI is challenging due to shot-to-shot variations in motion-induced phase errors, which disrupt SENSE reconstruction.
- Existing phase error correction methods are often incompatible with SENSE and cannot fully eliminate motion artifacts.
Purpose of the Study:
- To develop an effective algorithm for correcting motion-induced phase errors in multi-shot DWI.
- To integrate this phase correction method with SENSE reconstruction for improved multi-shot SENSE DWI.
- To demonstrate the efficacy of the proposed method on simulated and in vivo data.
Main Methods:
- An iterative conjugate-gradient (CG) algorithm was developed, treating phase error as an image encoding function.
- Diffusion-weighted images were reconstructed using an augmented sensitivity map and CG algorithm.
- The CG phase correction method was incorporated with SENSE reconstruction using a dynamic composite sensitivity for multi-shot SENSE DWI.
Main Results:
- The proposed CG algorithm effectively corrects motion-induced phase errors in multi-shot DWI.
- The method demonstrates successful multi-shot SENSE DWI reconstruction with acceleration factors (R) from 1 to 3.
- Effective phase correction and improved image quality were observed in both simulated and in vivo data acquired with PROPELLER and SNAILS sequences.
Conclusions:
- The proposed iterative CG algorithm provides effective phase correction for multi-shot SENSE DWI.
- This method overcomes limitations of previous techniques, enabling robust motion artifact reduction.
- The algorithm facilitates improved image quality in multi-shot DWI applications, particularly with parallel imaging techniques.