History of medical imaging.

noticed that the invisible rays were able to penetrate some solids (like human fl esh) better than others (like bone or metal). He confi ned himself to his basement laboratory in Wurzburg, Germany, for six weeks while Frau Roentgen brought him meals. During that time he discovered most of what the world would know about X-rays for the next twenty years. For his efforts he was awarded the fi rst Nobel Prize in 1901.X-ray is the basis for what we radiologists call “plane fi lms” or sim-ply “X-rays” used commonly for evaluating the chest and bone frac-tures. The original X-ray fi lms had to go through a wet developer pro-cess in a dark room. If the study was crucial, the radiologist would read it while it was still dripping wet. The term “wet reading” is still used for an emergency radiology report even though many X-rays today are ac-quired digitally without any fi lm at all.As the X-ray beam became more powerful, patient motion could be visualized and “fl uoroscopy” became possible. In the 1920s, radiolo-gists began giving patients radio-opaque barium as a swallow or an en-ema and taking fi lms as the barium traversed the gastrointestinal tract. That is how cancers of the esophagus, stomach, and bowel as well as ulcers, diverticulitis, and appendicitis were initially diagnosed by radi-ologists. Fluoroscopy is still in common use today, but it has advanced considerably. In the early days the images were so dim that radiologists had to wear red goggles all day to minimize the time needed to accom-modate to the dim light when they went back into the fl uoroscopy suite. Today, with modern image intensifi ers, that is no longer necessary. In addition, many of the diseases initially diagnosed by fl uoroscopy are now diagnosed by computed tomography (CT: see below).