Wilhelm Röntgen X-rays, a non-profit organization maintains his laboratory and provides guided tours to the Röntgen Memorial Site. <br> World Radiology Day: The International Day of Radiology is an annual event promoting the role of medical imaging in modern healthcare. It is celebrated on November 8 each year, coincides with the anniversary of the discovery of X-rays by Wilhelm Roentgen in 1895. It was first introduced in 2012, as a joint initiative, by the European Society of Radiology (ESR), the Radiological Society of North America (RSNA), and the American College of Radiology (ACR). Röntgen Peak in Antarctica is named after Wilhelm Röntgen.
Roentgen (unit) 1962 it was redefined. The CCU decided to define the SI unit of absorbed radiation in terms of energy per unit mass, which in MKS units was J/kg. This was confirmed in 1975 by the 15th CGPM, and the unit was named the "gray" in honour of Louis Harold Gray, who had died in 1965. The gray was equal to 100 rad. The definition of the roentgen had had the attraction of being relatively simple to define for photons in air, but the gray is independent of the primary ionizing radiation type, and can be used for both kerma and