Tomography using a rotating slant-hole collimator and a large number of projections.

A tomographic method using a limited-view angle has been evaluated. In studies using a gamma camera and a rotating 30-degree slant-hole (RSH) collimator, 64 projection images were registered. A special filtered backprojection technique was used for reconstruction of section images parallel to the collimator face. Resolution within such sections was 0.6 cm, 3 cm from the collimator face and 1.3 cm at 18 cm. Depth resolution was 2.2 cm at 3 cm and 5.1 cm at 18 cm. Spacing between section images was regular and geometric distortion negligible. Short-axis section images of a myocardium in vivo were qualitatively comparable or better than those obtained with single-photon emission computed tomography. Degradation in the posterior wall due to attenuation and scatter was less. Section images of the facial bones and a hip joint further demonstrated the tomographic capability of the method.