CLINICAL MEDICINE

Detailed explanation-1: -roentgen (R) The unit of exposure. One roentgen equals the amount of x or gamma radiation required to produce ions carrying a charge of 1 electrostatic unit (esu) per cubic centimeter (2.58 × 10− 4 coulomb per kg) of dry air under standard conditions.

Detailed explanation-2: -The rad, which stands for radiation absorbed dose, was the conventional unit of measurement, but it has been replaced by the Gy. One Gy is equal to 100 rad.

Detailed explanation-3: -The roentgen (symbol R) or röntgen (in German) is a legacy unit to measure radiation exposure. It was defined as the quantity of x-rays that produce 2.580 × 10-4 coulombs of charge collected per unit mass (kilograms) of air at standard temperature and pressure (STP): 1 R = 0.000258 coulombs per kilogram (Ckg-1) of air.

Detailed explanation-4: -roentgen, unit of X-radiation or gamma radiation, the amount that will produce, under normal conditions of pressure, temperature, and humidity, in 1 kg (2.2 lbs) of air, an amount of positive or negative ionization equal to 2.58 × 10−4 coulomb. It is named for the German physicist Wilhelm Conrad Röntgen. See also rem.

Detailed explanation-5: -In view of its uncertain nature, he called the phenomenon X-radiation, though it also became known as Röntgen radiation. He took the first X-ray photographs, of the interiors of metal objects and of the bones in his wife’s hand.