Spatial correspondence between [18F]NaF PET uptake and bone strain in the tibia

Motivation: Characterizing the relationships between loading and remodeling in vivo is important to understanding bone adaptation and pathophysiology. [18F]NaF PET may be a useful approach to interrogate this relationship. Goal(s): To evaluate spatial relationships between finite element-predicted strain and changes in [18F]NaF uptake. Approach: Finite element models were generated from MRI images to compute strains. PET images obtained simultaneously were used to compute [18F]NaF uptake before and after exercise. Mean standardized uptake and change in uptake were compared between regions experiencing different levels of strain. Results: Mean change in tracer uptake was greater in regions of very high tensile strain. Impact: [18F]NaF PET in combination with finite element analysis is a promising approach that can be used to improve our understanding of relationships between bone metabolism and loading, and of the pathophysiology of bone conditions.