Three-Dimensional Spatial, Density, and Temporal Resolution of the Dynamic Spatial Reconstructor

Abstract

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 1 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. Spatial resolution was essentially the same in the transverse and axial directions. Retrospective manipulation of the image data was important for maximization of spatial and density resolution in any structure under examination by obtaining a trade-off with partial-volume and motion-blurring effects. Maximum spatial resolution in the scanned volume was shown, under ideal conditions, to be greater than 5 hole pairs/cm. Under conditions of i.v. 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 3 hole pairs/cm; and in an adult human weighing approximately 60 kg, a resolution of about 2 hole pairs/cm is to be expected.