FedGAT: Unleashing Model-Agnostic Generative AI for Private & Powerful MRI Reconstruction

By Valiyeh A. Nezhad, Gokberk Elmas, Bilal Kabas, Fuat Arslan, Emine U. Saritas, Tolga \c{C}ukur


Published on November 10, 2025| Vol. 1, Issue No. 1

Summary

FedGAT introduces a novel federated learning approach for MRI reconstruction that overcomes the architectural homogeneity requirement of traditional FL. It achieves this by first collaboratively training a global generative prior - adapted from a natural image foundation model - which is then fine-tuned with site-specific prompts. In a second tier, each institution independently augments its local data with privacy-preserving synthetic MRI images generated by this prior, enabling them to train their preferred reconstruction models. This model-agnostic technique significantly enhances both within- and cross-site MRI reconstruction performance and generalization, particularly in environments where different sites utilize diverse model architectures.

Why It Matters

This research represents a significant leap forward for AI adoption in critical, data-sensitive domains like healthcare. Traditionally, the benefits of advanced AI models in medical imaging have been hampered by two major challenges: the scarcity of large, diverse datasets at individual institutions and the strict privacy regulations preventing raw data sharing. Federated Learning offered a partial solution, but its requirement for architectural homogeneity often proved impractical for hospitals with diverse existing infrastructure and varying computational resources.

FedGAT addresses these fundamental limitations by introducing true model agnosticism to federated learning, allowing institutions to leverage their preferred, tailored reconstruction models while still benefiting from a collaborative, global intelligence. The innovative use of a generative prior to create high-fidelity, privacy-preserving synthetic data is a game-changer. It transforms generative AI from merely a content creation tool into a powerful mechanism for data augmentation and knowledge transfer across distributed systems. This approach not only boosts model generalization and performance but also significantly lowers the barrier to entry for smaller or less resource-rich institutions, democratizing access to cutting-edge AI capabilities.

For AI professionals, this signals a crucial trend: the evolution of federated learning into more sophisticated, hybrid architectures that combine distributed training with generative models to overcome practical constraints. It underscores the increasing strategic value of synthetic data generation as a privacy-preserving enabler for AI development in regulated industries. Furthermore, the adaptation of a natural image foundation model for a highly specialized medical task highlights the ongoing power of transfer learning and the potential for leveraging large, pre-trained models across diverse domains. FedGAT doesn't just improve MRI reconstruction; it redefines the possibilities for collaborative, privacy-preserving AI in real-world, heterogeneous environments, setting a new standard for how AI can be deployed at scale in sensitive sectors.

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