Computed Tomographic Imaging of the Coronary Arterial Tree—Use of Local Tomography

Several years ago we demonstrated that coronary artery anatomy can be visualized using high-speed, volume-scanning X-ray CT. Using only a single bolus injection of contrast medium, the tomographic volume image, following appropriate image processing, (a) provides all angles of views of the coronary arterial tree and (b) overcomes the problem of the superposition of dye-filled cardiac chamber and pulmonary vessels on the coronary arteries. The current study demonstrates that local image reconstruction (i.e., reconstruction kernel is ∼ 2+ mm long), as distinct from more conventional global image reconstruction (i.e., 200+ mm kernel length), has the advantage that it reduces the need for operator interactive image processing. In addition, this algorithm eliminates the need for recording the X-ray projection data over the full transaxial extent of the thorax because it requires only the X-ray attenuation data over the region of the heart. This latter aspect reduces the dynamic range requirements for the sensors and could possibly reduce total X-ray exposure.