In 1963 and 1964 Allan Cormack published the theoretical foundations of computer tomography in the Journal of Applied Physics. In 1972 the first computed tomographic scanner was built by Godfrey Hounsfield who, together with Allan Cormack, was awarded the Nobel Prize in Physiology or Medicine in 1979. The basic idea of computerised tomography is the illumination of an object by x-rays from numerous different angles.

Our educational x-ray apparatus ( preferred with W tube) allows the illumination of objects by x-rays. The resulting 2D-projections are visualised at the fluorescence screen. These projections have a relatively low intensity. Therefore a camera of high sensitivity has to be used to record the various projections. Such a camera is implemented in the computed tomography module.

By turning an object using the built-in goniometer of the x-ray apparatus, and recording the 2D-projections from each angular step, the computer can reconstruct the object illuminated by x-rays. Our e-learning software visualises the back projection ( necessary for reconstructing the computed tomogram) concurrently with the scanning process. The 3D-model is then displayed on the PC screen.

CT Scan of a Frog
A frog is turned in a polystyrene ball with the goniometer of the x-ray unit. The 2D-projections on the fluorescence screen provide the original data for the backprojection, by which the software computes the 3D-model of the frog:

The backprojection of the frog can be viewed as three-dimensional representation. Particularly at the beginning the backprojected beams can easily been observed:

CT Scan of a Kinder Surprise
The included toy will be already recognised in the closed plastic egg:

Lego CT Scan

PC Requirements

The real-time recording and evaluation of a computed tomogram need a powerful CPU and graphics card. Therefore we provide the videos for your convenience.

For performing CT scans the following minimum requirements apply:

* Windows XP SP2 or Windows Vista ( 32 bit or 64 bit)
* Dual-Core CPU 2 GHz
* 2 GB RAM
* DirectX 9 compatible 3D-graphics card with shader model 3 support and 256 MB RAM ( Nvidia GeForce 7600 / 8600 or better)
* Screen resolution 1024x768 ( TrueColor)
* USB 2.0 port

For larger computed tomograms we recommend a more powerful PC:

* Windows Vista ( 32 bit or 64 bit)
* Quad-Core Prozessor 2, 4 GHz
* 3 GB RAM
* DirectX 9 compatible 3D-graphics cards with shader model 3 support and 512 MB RAM ( ATI Radeon 3850 / Nvidia GeForce 8800 or better)
* Screen resolution 1280x1024 ( TrueColor)
* USB 2.0 port