  Artificial Intelligence (AI) is having a tremendous impact across most areas
of science. Applications of AI in healthcare have the potential to improve our
ability to detect, diagnose, prognose, and intervene on human disease. For AI
models to be used clinically, they need to be made safe, reproducible and
robust, and the underlying software framework must be aware of the
particularities (e.g. geometry, physiology, physics) of medical data being
processed. This work introduces MONAI, a freely available, community-supported,
and consortium-led PyTorch-based framework for deep learning in healthcare.
MONAI extends PyTorch to support medical data, with a particular focus on
imaging, and provide purpose-specific AI model architectures, transformations
and utilities that streamline the development and deployment of medical AI
models. MONAI follows best practices for software-development, providing an
easy-to-use, robust, well-documented, and well-tested software framework. MONAI
preserves the simple, additive, and compositional approach of its underlying
PyTorch libraries. MONAI is being used by and receiving contributions from
research, clinical and industrial teams from around the world, who are pursuing
applications spanning nearly every aspect of healthcare.
