Test-Retest Reliability of Median and Ulnar Nerve DTI: Comparison on Local PCA and Patch2self Denoising Methods

Motivation: Peripheral nerve FA values characterize neuropathies but require high spatial resolution, resulting in low SNR data. Goal(s): To compare the effectiveness of two denoising methods, Patch2self and Local PCA, and evaluate the resulting test-retest reliability. Approach: The Peripheral nerve DTI data was denoised using Patch2self and Local PCA. Mean FA values and test-retest reliability was evaluated with and without denoising. Results: Patch2self and Local PCA both improved the SNR, but Patch2self increased the variability, suggesting it removed some signal with the noise. Local PCA maintained test-retest characteristics. Impact: Peripheral nerve injuries result in loss of sensorimotor function. FA from DTI can report on injury severity, but DTI requires high spatial resolution which results in low SNR data. Effective denoising is required to improve the quality of the data.