Cat Scan History


Allan Cormack and Godfrey Hounsfield received the 1979 Nobel Prize in Physiology or Medicine for inventing the first clinical CAT scanner for scanning the brain. In November 1975, Robert Ledley, a professor at Georgetown University, patented the whole-body CAT scan.

First-Generation CAT Scan

The original CAT scanner required pressing the patient's head against a rubber membrane and into a water-filled box. The box rotated in 1-degree increments while a single, narrow X-ray beam and single-detector assembly collected data during a five- to six-minute scan.

Second-Generation CAT Scan

After the first full-body CAT scanner was introduced, the image quality was greatly improved with the second-generation scanner. It used 20 or more narrow beams and detectors, which allowed a complete scan in the time the patient could hold a breath.

Third-Generation CAT Scan

The X-ray beam was widened into a fan shape to cover the entire width of the patient. An array of 250 or more detectors was linked to the X-ray tube, which rotated together around the patient in less than five seconds.

Fourth-Generation CAT Scan

By 1976, scanning in a mere second was achieved using a large, stationary ring of detectors that required only the X-ray tube to rotate around the patient.

Modern CAT Scan

Current CAT scan designs can complete a scan in as little as one-third a second. A CAT scan, also called a CT scan, uses X-rays and computer-assisted tomography to generate a 3-D image of organs, bone, soft tissue and blood vessels. Since the 1970s, this technology has provided a non-invasive alternative to exploratory surgery.