Computed Tomography 

CTComputed Tomography – is the name given to the process of generating 2-D and 3-D cross-sectional images of an object from flat X-ray images. CT works by taking digital radiographic images at a large number of positions around 180° of the circumference of a component. By a process similar to triangulation, the features generating the density changes on the radiographs can be positioned within the cross-section of the component. To generate a 3-D image, a number of such cross-sections are produced and stacked on top of each other.
CT can g
enerate 3-D images of cracks within the component under inspection and can be a better alternative to destructive examination. However, the component under test must be small enough to be accommodated by the particular CT equipment and be fully penetrated by the X-ray energies used by that CT system.

The Figure shows a 3-D tomographic reconstruction of a crack (courtesy of KA
NDE International Ltd).

For more information on CT see:




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