μCT images of a knee joint of a non-arthritic mouse perfused with lead containing contrast agent. (A) Axial and (B) oblique coronal multiplanar reformations (MPR). (C) Maximum intensity projection (MIP) showing similarity in image contrast of bone and contrast agent filled blood vessels. Beam hardening artifacts, which complicate vessel segmentation, are visible as dark bars between tibia and fibula in (A). (D) Separation of volume of interest (VOI)Capsule into four different analysis VOIs 1–4.