Normally CT shows 2D pictures of planes through the object (the mathematical algorithm is called the 2D Radon transform, after the Hungarian scientist Radon who created the mathematics as early as 1917 !). Pinhole detectors measure pencil-like beams of radiation. A 3D image database can be formed by stacking the 2D picture planes behind another. But only few people known that 3D information also can be obtained by using the 3D Radon transform (instead of the 2D) and measuring the radiation from 2D planes instead of pencil beams.
Actually the 3D Radon transform is mathematically simpler and more robust than the 2D (if you want to know more about the mathematics go to the shop). We constructed and tested a true 3D emission scanner measuring planes through an irradiated sample. Results of a true 3D reconstruction of a radioactive sphere can be found in the shop.
A very interesting application is the combined use of 3D CT and 3D printing. You obtain the 3D density distribution of an object and 3D Print the object using the density distribution. The interior of a living creature or a non dismantable object can be visualized on screen but also in a 3D hard copy!
- first true 3D computerised scanner