Three-dimensional spatial, density, and temporal resolution of the dynamic spatial reconstructor

Spatial, density, and temporal resolution of the dynamic spatial reconstructor (DSR), a multiple X-ray source, high speed, computed tomography scanning system, are evaluated. Hole-pair resolution was evaluated in a stationary phantom surrounded with air, 15 cm of water, or 20 cm of water. Temporal resolution was evaluated by rotation of one of the resolution phantoms during the scan, and with a balloon inflated to a known volume and at a known rate to approximate a typical left ventricular chamber volume and filling rate. These studies confirmed that the spatial resolution is essentially the same in the transverse and axial directions, and that retrospective manipulation of the image data is important for maximization of spatial and density resolution in any structure under examination by obtaining a tradeoff with partial-volume and motion-blurring effects. Maximum spatial resolution in the scanned volume was shown, under ideal conditions, to be greater than five hole pairs per centimeter. Under conditions of intravenous injection of contrast agent, the resolution of blood vessels in an experimental animal approximately 25 kg in weight is expected to be on the order of three hole pairs per centimeter; and in an adult human weighing approximately 60 kg, a resolution of about two hole pairs per centimeter is to be expected.