Robert Ledley, American physiologist and physicist, invented the CT scanner (born 1926)

Robert Steven Ledley, professor of physiology and biophysics and professor of radiology at Georgetown University School of Medicine, pioneered the use of electronic digital computers in biology and medicine. In 1959, he wrote two influential articles in Science: "Reasoning Foundations of Medical Diagnosis" and "Digital Electronic Computers in Biomedical Science". Both articles encouraged biomedical researchers and physicians to adopt computer technology.

A computed tomography scan, formerly called computed axial tomography scan, is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or radiology technologists. CT scanners use a rotating X-ray tube and a row of detectors placed in a gantry to measure X-ray attenuations by different tissues inside the body. The multiple X-ray measurements taken from different angles are then processed on a computer using tomographic reconstruction algorithms to produce tomographic (cross-sectional) images of a body. CT scans can be used in patients with metallic implants or pacemakers, for whom magnetic resonance imaging (MRI) is contraindicated.