Fig. 2
Overview of the animation processes leading to the quantification of a single-plane and biplanar displacements. a Imaging volume calibration: (i) the calibration grid with orientation of the plates in space, (ii) MRI coil with orientation of the imaging volume, (iii) & (iv) pre- and post-digitized bead images from the grid. b (i) Shows positioning of a translation trial. The solid-body models are spaced ~10 mm apart flat on a foam platform. The lower cube has been translated by 0.5 mm to the right relative to the upper cube, indicated by a wooden pointer (asterisk) and measured by the caliper. The orientation of the displacement has been shown by the coordinate axis. (ii) View of the wooden cubes. (iii) High-resolution axial T1 image slice through a cube. (iv) Representative 3-D model of a segmented cube. (v) Model as viewed after being imported into the animation environment. c (i) Representative image from a single-plane translation trial with the T1 sequence. (ii) Representative image from a single-plane rotation trial with the contrast-enhanced sequence. d (i) Representative single-plane rotoscoping “scene.” The image slice (off-white background) lies obliquely across the figure. The solid-body shadow is visible with its outline in the image slice (lower arrow). Upper half of the superimposed cube model is visible (upper arrow) with the anatomical axis. (ii) Image frame from a translation trial viewed from the top of the animation scene. The two cube models are cut through by the image slice (dark horizontal plane) across the hourglass holes within the models. (iii) Orthogonal image slices with registered 3D models