Osteoporosis with resultant fractures is a major global health problem with huge socioeconomic
implications for patients, families and healthcare services. Areal (2D bone mineral
density (BMD) assessment is commonly used for predicting such fracture risk, but is unreliable,
estimating only about 50% of bone strength. By contrast, computed tomography (CT) based
techniques could provide improved metrics for estimating bone strength such as bone volume
fraction (BVF; a 3D volumetric measure of mineralised bone), enabling cheap, safe and reliable
strategies for clinical application, and to help divert resources to patients identified as most likely
to benefit, meeting an unmet need.
Here we describe a novel method for measuring BVF at clinical-CT like low-resolution
(550µm voxel size). Femoral heads (n=8) were micro-CT scanned ex-vivo. Micro-CT data were
downgraded in resolution from 30µm to 550µm voxel size and BVF calculated at high and low
resolution. Experimental mechanical testing was applied to measure ex vivo bone strength of
samples. BVF measures collected at high-resolution showed high correlation (correlation
coefficient r2=0.95) with low-resolution data. Low-resolution BVF metrics showed high correlation
(r2=0.96) with calculated sample strength. These results demonstrate that measuring BVF at low
resolution is feasible, which also predicts bone strength. Measures of BVF should be useful for clinically estimating bone strength and fracture risk. The method needs to be validated using clinical CT scans.