Three-dimensional bone imaging: optical coherence tomography versus micro computer tomography

Optical coherence tomography (OCT) and micro-computed tomography (μCT) were applied to a bone sample, a 3x4x4mm cube of fixed substantia spongiosa from an arthritic human hip. Three-dimensional image sets (1.0mm x 0.9mm x 1.6mm) were acquired with both imaging systems for the same volume of interest. For better navigation, the sample surface was additionally imaged with microscopy. The resulting OCT images were compared stepwise to the according μCT images, showing a high correlation regarding the visualization of individual trabeculae. System based imaging differences were also found: due to scattering, OCT is limited to an imaging depth of about 1mm, while μCT is capable of imaging the complete trabecular bone architecture. However, OCT images cells and the inner bone structures in contrast to μCT at similar nominal resolutions (5μm respectively 6.5μm).