IM-MoCo: Self-supervised MRI Motion Correction using Motion-Guided Implicit Neural Representations

TL;DR

This paper introduces IM-MoCo, a novel self-supervised MRI motion correction method using motion-guided implicit neural representations, significantly improving image quality and diagnostic classification in motion-affected MRI scans.

Contribution

The paper presents a new instance-wise motion correction pipeline leveraging motion-guided INRs, effectively addressing severe motion artifacts while preserving anatomical structures.

Findings

Improves SSIM by 5% over state-of-the-art methods

Enhances PSNR by 5 dB and HaarPSI by 14%

Increases classification accuracy by at least 1.5 percentage points

Abstract

Motion artifacts in Magnetic Resonance Imaging (MRI) arise due to relatively long acquisition times and can compromise the clinical utility of acquired images. Traditional motion correction methods often fail to address severe motion, leading to distorted and unreliable results. Deep Learning (DL) alleviated such pitfalls through generalization with the cost of vanishing structures and hallucinations, making it challenging to apply in the medical field where hallucinated structures can tremendously impact the diagnostic outcome. In this work, we present an instance-wise motion correction pipeline that leverages motion-guided Implicit Neural Representations (INRs) to mitigate the impact of motion artifacts while retaining anatomical structure. Our method is evaluated using the NYU fastMRI dataset with different degrees of simulated motion severity. For the correction alone, we can improve over state-of-the-art image reconstruction methods by $+5\%$ SSIM, $+5\:db$ PSNR, and $+14\%$ HaarPSI. Clinical relevance is demonstrated by a subsequent experiment, where our method improves classification outcomes by at least $+1.5$ accuracy percentage points compared to motion-corrupted images.