Computer Tomosynthesis: A Versatile Three-Dimensional Imaging Technique

Tomosynthesis permits the representation of internal structures of an object by an arbitrary number of frontal sections (tomosynthetic slices), from a finite set of radiographs, each imaging the object at a different projection angle. Tomosynthetic reconstructions produce a sharp image of structures lying in the desired tomosynthetic slice, on which blurred images of object detail lying outside the plane of interest are superimposed. Slice thickness is largely determined by the projection angle. Advantageous features of tomosynthesis are the limited size of the projection angle required, the selective positioning of the tomosynthetic plane after recording of the radiographs, and the computational simplicity permitting real-time implementation. Applications to dental radiography demonstrate the feasibility to synthesize tomographic slices with a thickness of about 3 mm from as few as 8 radiographs exposed on a circular projection cone with half-angle of 4.5°. The reconstructions not only indicate the relative spatial position of the dental tissues, but also show clinically relevant structures not visible in the original radiographs