Simulated ECT of the left ventricle using rotating slant-hole collimator and two camera positions.

Limited-angular-range tomography leads to an elongating distortion of the object in the direction of the z axis (perpendicular to the camera face). Two-view tomography appends to the usual data set another set of projections taken after the camera is rotated 90 degrees about an axis perpendicular to z. We investigated two-view tomography using a rotating-slant-hole collimator, 12 projections per view and the SMART iterative algorithm. Computer simulations extended previous results to include noise and attenuation. Phantoms imaged were the Au-rings in air and a ventricle phantom angled with respect to the z axis and placed in a water bath. Two-view results were generally superior compared to one-view results, were subject to some artifact in imaging defects, but could detect defects by looking at the differences between two sets of images, and were fairly insensitive to ventricle angulation. Therefore, two-view tomography has promise for thallium-type imaging.