Brightfield microscopy image (left), CT image (middle), and a merge of the two (right). Arrows indicate single HA crystal measuring 300 µm × 100 µm. CT parameters included: 45 kVp, 177 µA current, 3000 ms/projection, 360 projections/rotation, and a detector pixel size of 48 µm. FM = Iodine-containing fiducial markers. See also Supplementary Video.