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Related Experiment Video

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Picometer-Precision Atomic Position Tracking through Electron Microscopy

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Reference-free single-pass EPI Nyquist ghost correction using annihilating filter-based low rank Hankel matrix

Juyoung Lee¹, Kyong Hwan Jin¹, Jong Chul Ye¹

¹Bio-Imaging & Signal Processing Laboratory, Department of Bio and Brain Engineering, Korea Advanced Institute of Science & Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejon, 34141, Republic of Korea.

Magnetic Resonance in Medicine

|February 19, 2016

Summary

This study introduces a new single-pass method to correct Nyquist ghost artifacts in echo-planar imaging (EPI) without needing extra scans. The technique effectively removes ghosting by treating k-space data as a low-rank matrix completion problem.

Keywords:

MRI Nyquist ghost artifact annihilating filter echo-planar imaging pyramidal representation structured low rank Hankel matrix completion

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Area of Science:

Magnetic Resonance Imaging (MRI)
Image Reconstruction
Signal Processing

Background:

Echo-planar imaging (EPI) is prone to Nyquist ghost artifacts caused by odd and even echo inconsistencies.
Existing correction methods often require additional reference scans or multi-pass acquisitions, increasing scan time and complexity.

Purpose of the Study:

To develop a novel, accurate, single-pass EPI ghost artifact correction method.
To eliminate the need for additional reference data or multipass acquisitions in EPI ghost artifact correction.

Main Methods:

The method converts ghost correction into k-space data interpolation for even and odd echoes.
It leverages the sparse nature of differential k-space data, forming a low-rank Hankel structured matrix.
Annihilating filter-based low-rank matrix completion is used to recover missing data.

Main Results:

The proposed method was successfully applied to both single and multicoil EPI data.
Experimental results with in vivo data demonstrated complete removal of ghost artifacts.
The technique effectively suppressed ghosting without requiring prescan echoes.

Conclusions:

The novel method effectively suppresses EPI ghost artifacts by exploiting intrinsic image properties and an annihilating filter relationship.
This single-pass approach offers an accurate and efficient solution for ghost artifact correction in EPI MRI.
The method eliminates the need for prescan steps, streamlining the imaging protocol.