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Recognized effects of higher acute radiation doses are described in more detail in the article on radiation poisoning.Although the International System of Units (SI) defines the sievert (Sv) as the unit of radiation dose equivalent, chronic radiation levels and standards are still often given in units of millirems (mrem), where 1 mrem equals 1/1,000 of a rem and 1 rem equals 0.01 Sv.
The average radiation dose from an abdominal X-ray is 0.7 millisieverts (0.0007 Sv), that from an abdominal CT scan is 8 mSv, that from a pelvic CT scan is 6 mGy, and that from a selective CT scan of the abdomen and the pelvis is 14 mGy. [7]
The rep has variously been defined as 83 or 93 ergs per gram of tissue (8.3/9.3 mGy) [13] or per cc of tissue. [14] In 1953 the ICRU recommended the rad, equal to 100 erg/g as a new unit of absorbed radiation, [15] but then promoted a switch to the gray in the 1970s.
Dose area product (DAP) is a quantity used in assessing the radiation risk from diagnostic X-ray radiography examinations and interventional procedures, like angiography.It is defined as the absorbed dose multiplied by the area irradiated, expressed in gray-centimetres squared (Gy·cm 2 [1] – sometimes the prefixed units dGy·cm 2, mGy·cm 2 or cGy·cm 2 are also used). [2]
In 1953 the International Commission on Radiation Units and Measurements (ICRU) recommended the rad, equal to 100 erg/g, as the unit of measure of the new radiation quantity absorbed dose. The rad was expressed in coherent cgs units. [5] In 1975 the unit gray was named as the SI unit of absorbed dose. One gray is equal to 1 J/kg (i.e. 100 rad).
For comparison, radiation levels inside the United States Capitol are 85 mrem/yr (0.85 mSv/yr), close to the regulatory limit, because of the uranium content of the granite structure. [14] The NRC sets the annual total effective dose of full body radiation, or total body radiation (TBR), allowed for radiation workers 5,000 mrem (5 rem). [15] [16]
The V 1298 Tau star system contains four young planets, orbiting close to their parent star, where they are baked in X-ray radiation. Orbiting the young star V 1298 Tau, more than 350 light-years ...
The flight-time equivalent dose concept is the creation of Ulf Stahmer, a Canadian professional engineer working in the field of radioactive materials transport. It was first presented in the poster session [1] at the 18th International Symposium of the Packaging and Transport of Radioactive Materials (PATRAM) held in Kobe, Hyogo, Japan where the poster received an Aoki Award for distinguished ...