Figure 6a. Detector configurations and voxel dimensions at 16-channel multidetector CT. (a) Left: Diagram shows narrow collimation, with exposure of only the central 16 detector elements. Each element functions as a separate unit, and 16 sections with a thickness of 0.625 mm each are acquired per gantry rotation. Right: Diagram shows that the reconstructed voxels are isotropic, with about equal length in each dimension. (b) Left: Diagram shows wide collimation, with exposure not only of the central small elements but also of larger elements at the periphery. Central elements function in pairs, and peripheral elements are used individually. As a result, 16 sections with a thickness of 1.25 mm each are acquired per rotation. Right: Diagram shows that reconstructed voxels are anisotropic, about twice as long in the longitudinal plane as in the transverse plane.