Digital tomosynthesis: technique for electronic reconstructive tomography

A technique is described for obtaining tomographic images through retrospective reconstruction of digital data. The apparatus used for this technique, called digital tomosynthesis consists of a linear tomographic x-ray machine that has been modified by the addition of a fluoroscope and TV system, a video disk recorder, an analog-to-digital converter, and a small computer for data processing and manipulation. Video frames are collected and stored during a single tomographic sweep. The stored data are then digitized and retrospectively processed in the computer for reconstruction of any desired tomographic plane within the body. The major advantages of DTS include short patient study time, low radiation dose compared with conventional tomography, the ability to enhance the digitized image through manipulation of window and level display, and the applicability of this technique to dynamic studies such as angiotomography. Phantom studies show good diagnostic quality of the resulting images, and preliminary vascular studies in dogs indicate the clinical potential of this technique for use in digital subtraction angiotomography.