Clinical diagnostic quality digital radiographs of 20 radii were acquired by using a Philips Medio (Philips Healthcare, Andover, MA) 50 CP-H in the Department of Medical Imaging, Royal University Hospital in Saskatoon. From the total sample of 20, 1 0 specimens that reflected a broad range of apparent trabecular morphologies were selected for DEI at the CLS synchrotron by using the 05B1-1 beam line at 41 keV, with a surface exposure typically of 2 mGy. The monochromator and analyser used single crystal silicon crystals with the (3, 3, 3) lattice planes. The DEI technique has been described previously 6, and thus we provide only a general summary here. Briefly, a single energy beam is extracted from a polychromatic synchrotron x-ray beam by using a double crystal monochromator. The high flux (intensity) of the synchrotron source ensures that sufficient photons remain after selection of a single energy. This beam passes through the target sample and is reflected off the third crystal known as the "analyser" before arriving at the detector. The placement of the analyser crystal between the sample and the detector is a defining feature of DEI. The condition for x-ray diffraction from the analyser crystal is met only when the incident beam makes the correct angle to the atomic lattice planes in the crystal for a given x-ray energy or wavelength. When this condition is met, the beam diffracts from the analyser over a very narrow range of incident angles. As the analyser is rotated, the intensity variation observed is referred to as the rocking curve. Because the range of angles that can be accepted by the analyser is only a few microradians (I microradian = 57 microdegrees = 0.21 arc-seconds), the analyser provides scatter rejection at the microradian level, which is below the capabilities of conventional antiscatter techniques, such as slit collimation and grids. Small angle scattering arises from diffraction from structures with dimensions up to micron sizes. This scattering intensity, which would normally appear in the image, is missing and appears in the same way as absorption in the image. This scatter rejection contrast is called extinction contrast. Therefore, in DEI, the image that represents the absorption of the object by x-rays is referred to as the apparent absorption image because it has contrast derived from both absorption and scatter rejection. Notably, DEI provides particular improvement with respect to resolving pixel-sized objects 8. Refraction images have a high sensitivity for defining the boundaries between areas with differing refractive indices. It is this property of DEI that provides improved visualization of trabecular bone, which consists of a lattice-like solid structure surrounded by soft tissue (marrow). Although, in the past, DEI has been applied to bone 9-11, the potential to better visualize bone microarchitecture with the aim of improving the assessment of human bone at a clinically relevant fracture site has not yet been explored.