Tomosynthesis-3-D X-ray Imaging by Means of Holography or Electronics

Tomography is a well-established X-ray technique for imaging a medical object in its three dimensions by generating images of certain layers. This process, however, suffers from the disadvantage that only a single tomogram is produced at each exposure run. Tomosynthesis overcomes this restriction by using a set of discrete projection images to synthesize layers of arbitrary depth and of arbitrary number. This means that the object can be completely displayed with only one tomographic exposure run, thus saving time and dosage. After a brief description of the basic principle much attention will be devoted to the implementation of tomosynthesis. The reconstruction process has been experimentally realized by holography as well as by analogue video electronics. Implementation by digital electronics is also discussed. The strengths and weaknesses of the various techniques will be examined.