Since Roentgen's discovery of the X-ray in 1895, many scientific advancements have taken place. Inventors adapted their discoveries to the field, while physicians around the world became specialists and further developed the profession. They were the forerunners of today's radiologists and radiation oncologists. Germany-Berlin stamp features a portrait of Warner Von Siemens, the German inventor. Siemens died prior to Roentgen's discovery, but his company continues to be one of the world leaders in diagnostic and therapeutic equipment manufacturing.
Macedonia stamp features a modern mammography machine.
This stamp was issued to help with the country's fight against cancer. It shows a technologist sitting at the controls of a computerized tomography scanner. United States stamp was issued to honor Chester Carlson, inventor of the Xerox process, later applied to xeroradiography, once widely used in mammography. Monaco stamp features a portrait of Albert Einstein and his famous equation. While Einstein was not directly involved with the development of radiology, his pioneering work made it possible for other scientists to advance the field.