ACTA Model 0100 CT Scanner

CT (computed tomography), sometimes called CAT (computer-assisted tomography) scanning, uses x-ray equipment to obtain image data from different angles around the body, and then computers to process that information and show a cross-section of body tissues and organs. The advantage of CT imaging is that in addition to bone, it can show soft tissue such as lung and blood vessels with great clarity.
The 0100 ACTA Scanner (which stands for automated, computerized, transverse axial scanner) is the world's first whole-body scanner. Earlier machines scanned only the head, and needed a water bath. The ACTA scanner was invented by dentist and biophysicist Robert S. Ledley and put into clinical operation in 1973 at the Georgetown University Medical Center in Washington, D.C. NMAH acquired it in 1984.
The ACTA scanner joins other new imaging modalities being collected at the Museum, such as ultrasound and MRI, to document the major advances in body imaging since the discovery of x-rays in 1895.
Currently not on view
Object Name
CT scanner
Date made
ca 1974
Ledley, Robert S.
Pfizer Medical Systems Company
Physical Description
metal (overall material)
plastic (overall material)
overall: 177.3 cm x 63.6 cm x 80 cm; 69 13/16 in x 25 1/16 in x 31 1/2 in
Place Made
United States: District of Columbia, Georgetown, Georgetown University Medical Center
ID Number
accession number
Acta Scanner
See more items in
Medicine and Science: Medicine
Health & Medicine
Data Source
National Museum of American History, Kenneth E. Behring Center


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