Clinically feasible liver tumour cell size measurement through histology-informed in vivo diffusion MRI

Innovative diffusion Magnetic Resonance Imaging (dMRI) models enable the non-invasive measurement of cancer biological properties in vivo . However, while cancers frequently spread to the liver, models tailored for liver application and easy to deploy in the clinic are still sought. We fill this gap by delivering a practical, clinically-viable dMRI framework for liver tumour imaging, informing its design through histology. By comparing dMRI and histological data from mice and cancer patients, we select a dMRI signal model of restricted intra-cellular diffusion with negligible extra-cellular contributions, maximising radiological-histological correlations. The model enables non-invasive liver cancer phenotyping, providing cell size and density estimates that i) correlate with their histopathology counterparts, ii) are associated to cell proliferation and tumour volume, and iii) that distinguish tumour types. By delivering metrics that are biologically meaningful, our approach may complement standard-of-care radiology, and become a new tool for enhanced cancer characterisation in precision oncology.