Traditionally, museums have assessed antiquities and museum pieces with conventional xrays. This produces a 2D image of the object only (like a medical xray of a bone), which may be adequate in some circumstances but clearly fails to capture the 3D nature and layer-by-layer internal structure of an object. Therefore an antique xray may be an inadequate or suboptimal form of imaging an object.
As a consequence of 2D imaging, certain important areas of the object may be masked and remain hidden.
This problem is generally alleviated by CT scans as multiple xrays are taken around an object producing a 3D image.
A 2D antique xray through the mechanism, trigger and barrel of an 18th century musket. The 2D xray image has certain limitations including detail regarding the grain and integrity of the wood, for example. This is better achieved with CT scans which have higher contrast resolution.
(Image attributed to Lighthouse Archaeological Maritime Program)