In the 1970ies, with the advent of the first computer tomograph, the EMI Scanner Mark 1 (flickr.com/photos/voxel123/48882763522/), many companies started producing CT scanners - most of the systems are long forgotten.
The Omnimedical 4001 was a dedicated head CT scanner that became commercially available around 1979.
Title page of the product brochure: www.radhis.nl/uploads/5/5/4/1/55414293/schermafbeelding-2...
Photograph of the actual system: www.radhis.nl/uploads/5/5/4/1/55414293/omnimedical-omni-4...
This is a brick-built model