[Phantom measurements of spatial resolution and the partial-volume-effect in computer tomography (author's transl)].

The present work deals with the problem of demonstrating tissue changes of small volume by computer tomography. Measurements were carried out with the Somatom computer tomograph and evaluated by the Evaluscope (both Siemens); fourteen test situations were devised, using plexiglass rods of varying diameter and different penetration into the level being sectioned. Quantitative relationships were found concerning the spatial resolution for objects of varying sizes, concerning the partial volume effect and the thickness of the section for objects of varying size, and concerning the relationship between resolution and partial volume effect for small objects.