###### Abstract
As the intensity of tissues in \(\mu\)CT images is determined by radiodensity (the relative inability of x-rays to pass through a material), \(\mu\)CT is best suited for distinguishing different types of tissues, such as bone versus muscle. The use of radiopaque contrast agents allows for otherwise undetectable structures (vasculature, bone microdamage) to be visualized with \(\mu\)CT imaging [16; 17]. Images acquired with \(\mu\)CT can be acquired in as little as 20 min to 12 h depending on the sample size, desired voxel spacing, and image resolution. Biological samples may also remain hydrated and intact, as \(\mu\)CT scans are acquired at atmospheric pressure. \(\mu\)CT image quality is determined by the image acquisition parameters and reconstruction algorithm employed by the scanner but may further be improved with post-image acquisition techniques. \(\mu\)CT images inherently contain spatial blurring, which can be quantified by a point spread function (PSF) [18; 19; 20]. The PSF defines image resolution and is the result of blurring induced by the finite size of the focal spot size, the x-ray detector aperture (the spatial resolution of the detector itself) [21], and the scattering of x-rays [22]. Spatial blurring may result in thin bone features (such as trabeculae) having a diffuse appearance, which overestimates their thickness and underestimates their intensity. For microstructural analyses of bone, this may negatively affect the quality of results. The localization and quantification of contrast agents may additionally be disrupted, as blurring may reduce their intensity. The application of deconvolution algorithms, which act to reduce blurring and noise, may correct the PSF to render images more closely to their true representations. Non-destructive 3D assessment of damage is possible via \(\mu\)CT imaging with radiopaque contrast agents. Previous investigators have studied 3D skeletal microdamage distribution using \(\mu\)CT imaging of \(BaSO_{4}\)-labeled bovine and rodent bone [12; 23; 24]. Microdamage accumulation found in \(\mu\)CT images of \(BaSO_{4}\)-labeled human cortical bone cores has been strongly correlated with histologic crack density but with more variability [10]. BSE imaging of \(BaSO_{4}\)-labeled rodent vertebrae [25] has been shown to yield superior visualization of microcracks and crack nucleation surfaces compared to high-resolution \(\mu\)CT imaging. Trabecular bone contains a fine structure of mineralized tissue with individual strut thickness that can vary from 25-1000 \(\upmu\)m. Microdamage and cracks present within trabecular bone are on the order of microns to millimeters. As such, \(\mu\)CT-based microdamage assessments in trabecular bone are highly dependent on image acquisition parameters and the imaging system, given the overlap of resolution possible with \(\mu\)CT and the structures being imaged. This study aims to enhance \(\mu\)CT-based microdamage characterization in rat vertebrae labeled with \(BaSO_{4}\) contrast by careful consideration of the x-ray physics (k-edge x-ray adsorption), physical specimen size, limitations of \(\mu\)CT systems (focal spot size interaction with tube current and voltage), and post-acquisition enhancement (deblurring) [18; 26], and compare patterns of microdamage visualized with \(\mu\)CT to BSE imaging.