Fine-Tuning TransMorph with Gradient Correlation for Anatomical Alignment
This is an incremental improvement for interpatient brain MRI registration, addressing convergence stability and deformation smoothness in a domain-specific challenge.
The paper tackled the problem of improving anatomical alignment in unsupervised brain MRI registration by fine-tuning the TransMorph model with gradient correlation, resulting in slight improvements in Dice and HdDist95 scores and a notable reduction in NDV compared to the baseline.
Unsupervised deep learning is a promising method in brain MRI registration to reduce the reliance on anatomical labels, while still achieving anatomically accurate transformations. For the Learn2Reg2024 LUMIR challenge, we propose fine-tuning of the pre-trained TransMorph model to improve the convergence stability as well as the deformation smoothness. The former is achieved through the FAdam optimizer, and consistency in structural changes is incorporated through the addition of gradient correlation in the similarity measure, improving anatomical alignment. The results show slight improvements in the Dice and HdDist95 scores, and a notable reduction in the NDV compared to the baseline TransMorph model. These are also confirmed by inspecting the boundaries of the tissue. Our proposed method highlights the effectiveness of including Gradient Correlation to achieve smoother and structurally consistent deformations for interpatient brain MRI registration.