Extending the range of any fielded scanner can be a strategic asset for performing 3D CT imaging of objects and assemblies. In some cases the detector is just too small to cover the entire extent of the object for the standard 180/360 degree scan. Alternatively, sometimes the physical extent and aspect ratio of the object does not support a standard scan at the target spatial resolution for that spot size. Lastly, scanning moderately large, low-attenuating objects is better done with lower energy techniques, but lower-energy scanners often do not accommodate the larger footprint these objects require. This paper presents techniques for performing CT imaging in these circumstances. These include region of interest (ROI) scans, half-scans (offset-scans) and tiled-scans where multiple scans are required to cover the entire object. In each case the advantages and consequences of these choices for the inspection data are covered.

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