Large-Scale Pretraining for Improving Deep Learning-Based Geometric Distortion Correction of Diffusion-Weighted Imaging

Saroj Khanal; Yashawant Kumar Yadav; Kritam Bhattarai; Jeevan Neupane; Shristi Subedi; Saship Gwachha; Manish Kumar Tiwari; Dong Zhang; Confidence Raymond; Aondona Moses Iorumbur; Udunna Anazodo; Surendra Maharjan; Bishesh Khanal; Mahesh Shakya; Pralhad Kumar Shrestha

arXiv · 2609.06437

Large-Scale Pretraining for Improving Deep Learning-Based Geometric Distortion Correction of Diffusion-Weighted Imaging

Saroj Khanal·Yashawant Kumar Yadav·Kritam Bhattarai·Jeevan Neupane·Shristi Subedi·Saship Gwachha·Manish Kumar Tiwari·Dong Zhang·Confidence Raymond·Aondona Moses Iorumbur·Udunna Anazodo·Surendra Maharjan·Bishesh Khanal·Mahesh Shakya·Pralhad Kumar Shrestha

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Abstract

Diffusion-weighted imaging (DWI) is widely used in clinical settings but remains vulnerable to geometric distortion. Conventional correction methods often require additional acquisitions or vendor-specific solutions, limiting their feasibility in high-throughput, resource-constrained settings. This study investigates whether large-scale pretraining strategies can improve deep learning-based distortion correction for single-phase-encoding DWI. We formulate the task as image reconstruction, and compare a non-pretrained baseline against a self-supervised and a generative pretrained model, evaluated using both quantitative image-similarity metrics and qualitative expert assessment. The best-performing model was further tested for transferability on data collected in an LMIC setting with acquisition shift. Pretrained models outperformed the non-pretrained baseline, with cWDM achieving the strongest results across both quantitative and qualitative evaluation. However, application to LMIC data revealed transferability challenges, including contrast alteration and over-reliance on T1-weighted anatomical structure. Registering images to a common standard space improved predictions, suggesting that harmonized preprocessing may enhance cross-domain deployment.

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Saroj Khanal, Yashawant Kumar Yadav, Kritam Bhattarai, Jeevan Neupane, Shristi Subedi, Saship Gwachha, Manish Kumar Tiwari, Dong Zhang, Confidence Raymond, Aondona Moses Iorumbur, Udunna Anazodo, Surendra Maharjan, Bishesh Khanal, Mahesh Shakya, Pralhad Kumar Shrestha. 2026-09-06. Large-Scale Pretraining for Improving Deep Learning-Based Geometric Distortion Correction of Diffusion-Weighted Imaging. https://arxiv.org/abs/2609.06437

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