A Multimodal Biomedical Foundation Model Trained from Fifteen Million Image–Text Pairs

BackgroundBiomedical data are inherently multimodal, comprising physical measurements and natural-language narratives. A generalist biomedical artificial intelligence (AI) model needs to simultaneously process different modalities of data, including text and images. Therefore, training an effective generalist biomedical model requires high-quality multimodal data, such as parallel image–text pairs.MethodsHere, we present PMC-15M, a novel dataset that is two orders of magnitude larger than existing biomedical multimodal datasets, such as MIMIC-CXR, and spans a diverse range of biomedical image types. PMC-15M contains 15 million biomedical image–text pairs collected from 4.4 million scientific articles. Based on PMC-15M, we have pretrained BiomedCLIP, a multimodal foundation model, with domain-specific adaptations tailored to biomedical vision–language processing.ResultsWe conducted extensive experiments and ablation studies on standard biomedical imaging tasks from retrieval to classification to visual question answering (VQA). BiomedCLIP achieved new state-of-the-art results in a wide range of standard datasets, substantially outperforming prior approaches. Intriguingly, by large-scale pretraining on diverse biomedical image types, BiomedCLIP even outperforms state-of-the-art radiology-specific models, such as BioViL, in radiology-specific tasks such as Radiological Society of North America (RSNA) pneumonia detection.ConclusionsBiomedCLIP is a fully open-access foundation model that achieves state-of-the-art performance on various biomedical tasks, paving the way for transformative multimodal biomedical discovery and applications. We release our models at aka.ms/biomedclip to facilitate future research in multimodal biomedical AI.