## Materials and Methods
### Enhanced \(\mu\)CT Imaging  
These 11 slides prepared for BSE imaging were re-imaged with parameters selected to maximize contrast between \(BaSO_{4}\) and bone, also considering voxel spacing, resolution, and signal-to-noise ratio (SNR). SNR is proportional to the square root of the products of current, integration time, and frame averaging. The contrast between \(BaSO_{4}\) and bone is enhanced by maximizing the relative energy contribution of x-ray photons having energy just above the 37.4 keV k-edge of barium. The peak of the x-ray photon energy spectrum as a function of x-ray energy occurs at -1/3 of the tube voltage value. Selecting a tube voltage of 90 kVp, the maximum available, will therefore increase the fraction of x-ray photons with energy just below the k-edge of barium, maximizing contrast. By the same logic, the attenuation of lower energy photons also improves contrast and can be achieved by using an attenuating material with a sufficiently high atomic number such that photoelectric x-ray absorption becomes the dominant absorption process. Photoelectric absorption is more pronounced at lower photon energy, thereby removing the undesired lower energy photons. Thus, the 0.5 mm aluminum filter (1 of 3 options) used in the baseline scans sufficiently reduces the contribution of lower energy photons, reducing soft tissue contrast and beam hardening. This filter is suitable to be added to the x-ray beam for an enhanced set of image acquisition parameters. Reconstruction voxel spacing requirements are governed by the size of details of interest but must also consider computation limitations like processing time, memory, and storage, limiting the number of voxels. The image resolution should also be commensurate with voxel spacing, as storing a blurry image with a small pixel spacing is wasteful. The specification of smaller reconstructed voxel spacings limits the maximum sample holder diameter because the \(\mu\)CT uses geometric magnification, trading off the field of view to increase resolution at the detector. In this application, a voxel spacing of 4.9 \(\mu\)m (1 of 7 choices) was chosen with the sample holder of 14 mm inner diameter, the maximum value having an x-ray projection that can be encompassed by the detector. A higher x-ray tube current creates more x-ray photons per unit time, thereby increasing the SNR achievable per unit time of imaging. This requires a larger x-ray focal spot so as not to damage the x-ray anode due to excessive energy deposition density, increasing x-ray projection blurring at the detector. The tube current was thus limited to a value of 44 \(\mu\)A (1 of 5 choices available), so the associated (dependent) focal spot size does not cause noticeable blurring. Finally, the process of analyzing images and comparing modalities require \(\mu\)CT images with a minimum SNR, which depends on the square root of the number of detected x-ray photons for a given x-ray spectrum. This number, for a given x-ray tube current, is proportional to the amount of time that the x-ray detector collects radiation and is also known as the integration time [32; 33]. The Scanco \(\mu\)CT-100 additionally allows several images to be acquired at each projection angle and combined, a process labeled as frame averaging. Thus, the number of detected x-ray photons used to image a sample with a 2000 ms integration time and no averaging is the same as imaging with a 250 ms integration time and 8 times frame averaging. The former approach will, however, lead to a faster scan time. Frame averaging is useful when SNR requirements cannot be achieved by increasing the integration time alone. In these experiments, we chose to only vary frame averaging for descriptive simplicity. The SNR was evaluated by examining images with the above-specified parameters; frame averaging was increased up to 8 times to improve the SNR to offset limitations encountered with the use of low current.