The history and principles of optical computed tomography for scanning 3-D radiation dosimeters: 2008 update

The current status of optical CT for 3-D radiation dosimetry is reviewed. The technique is first placed in its historical context, pointing out the relationship with other methods of optical imaging and showing how optical-CT has emerged independently in several different fields and under different names. The theoretical background of the method is described briefly and this provides the foundation for an explanation of the different types of scanner. The relative advantages and disadvantages of instruments based on scanned lasers and pixelated (area) detectors are presented. The latest generation of "fast laser scanners" is described and the review is concluded with a discussion of the different radiation-sensitive materials used as samples in optical CT.