Autopsy of the living

A brief history of imaging science

Melissa Marino, Ph.D.
Published: February, 2006

Whole body scans, like this magnetic resonance image, can help physicians determine the extent of cancer spread throughout the body.  They also could be used routinely to screen healthy people for a gamut of diseases, although this use is controversial.
Courtesy of the Vanderbilt University Institute of Imaging Science
On the evening of November 8, 1895, an accidental discovery ushered in a scientific and medical revolution that would allow us to see inside the living human body for the first time.

While conducting an experiment with cathode rays, Wilhelm Roentgen, Ph.D., noticed a strange glow on a distant cardboard screen. Knowing that cathode rays could not pass through the obstacles between his cathode ray tube and the glow, he proposed the existence of a novel type of penetrating ray, which he called the “X-ray.” After spending several solitary weeks analyzing the rays, Roentgen published his findings in late December, along with an eerie X-ray photograph (radiograph) of his wife’s hand.

Roentgen’s discovery opened up the human body without a single incision. Soon, the medical profession was using X-rays to locate lodged bullets and bone fractures. With the further refinement of the technology and the development of contrast agents, even soft tissues came into focus.

Rock ‘n’ roll

Despite the improved resolution of contrast-enhanced X-ray images, overlying bones obscured some parts of the body from view. By moving the X-ray tube and film in tandem, bones that stood in the way were blurred out and a single cross-sectional slice through the body was highlighted.

This new technique, called tomography, was first described by the Dutch radiologist Bernard Ziedses des Plantes in 1931. Tomography could produce a series of images that could be stacked to give the physician information about volume. The first commercial tomograph, called the laminagraph, was built at the Mallinckrodt Institute of Radiology at Washington University in St. Louis in 1937.

Although laminagraphs are related to modern computed tomography (CT), such technology had to await the dawn of the computer age. A major player was a London-based electronics firm, Electric and Musical Industries Limited (EMI), perhaps best known as the Beatles’ record label.

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