1900
• German scientists Friedrich Giesel and Friedrich Walkhoff
discover that radium rays are dangerous to the skin; Pierre
Curie purposely leaves a radium sample on his arm for ten
hours and produces a sunburn-like rash. En route to a conference,
Henri Becquerel unthinkingly carries a sample in his
lower vest pocket and suffers a burn on his abdomen.
• Radiology begins to emerge as a medical specialty. It
becomes increasingly clear that producing an X-ray image
requires skill and technical know-how, and interpreting the
image requires a knowledge of anatomy.
1901
• Roentgen wins the first Nobel Laureate in Physics prize
for his discovery.
1904
• Clarence Dally, Thomas Edison’s assistant in X-ray research,
dies of extreme and repeated X-ray exposure. X rays had
already caused severe burns on his face, hands, and arms,
resulting in several amputations. From this point on, the risks
posed by radium and X rays become more clear. X-ray use
begins to be confined largely to doctor’s offices and hospitals.
1910
• Eye goggles and metal shields are commonly used to shield
X-ray users.
1917
• During World War I, X-ray equipment is an accepted component
of aid stations and hospitals in the field.
1919
• Dr. Carlos Heuser, an Argentine radiologist, is the first to use
a contrast medium in a living human circulatory system. The
compound, potassium iodide diluted with water, is acceptable
because it is excreted by the body and causes the blood vessels
to appear opaque on the X-ray image. Dr. Heuser successfully
injects the compound into a vein of a patient’s hand
and simultaneously takes an X ray to visualize the veins in
the forearm and arm. His discovery, however, is lost on the
scientific world because it is published only in Spanish, in an
Argentine medical journal.