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In diagnostic radiology, the F-factor is the conversion factor between exposure to ionizing radiation and the absorbed dose from that radiation. In other words, it converts between the amount of ionization in air (roentgens or, in SI units, coulombs per kilogram of absorber material) and the absorbed dose in air (rads or grays).
The NRC quality factors are independent of linear energy transfer, though not always equal to the ICRP radiation weighting factors. [9] The NRC's definition of dose equivalent is "the product of the absorbed dose in tissue, quality factor, and all other necessary modifying factors at the location of interest." However, it is apparent from their ...
If only part of the body is irradiated, then only those regions are used to calculate the effective dose. The tissue weighting factors summate to 1.0, so that if an entire body is radiated with uniformly penetrating external radiation, the effective dose for the entire body is equal to the equivalent dose for the entire body.
This is a special dosimetric quantity used to assess the dose from radiation exposure. [4] Another common measurement for human tissue is Gray (Gy, International or SI unit). [4] The reference for this sentence has a table that gives the exposure to dose conversion for these four materials. [10]
D T,R is the absorbed dose in tissue T by radiation type R and W R is the radiation weighting factor defined by regulation. Thus for example, an absorbed dose of 1 Gy by alpha particles will lead to an equivalent dose of 20 Sv. The radiation weighting factor for neutrons has been revised over time and remains controversial. This may seem to be ...
Doses of 200 to 1,000 rad delivered in a few hours will cause serious illness, with poor prognosis at the upper end of the range. Whole body doses of more than 1,000 rad are almost invariably fatal. [3] Therapeutic doses of radiation therapy are often given and tolerated well even at higher doses to treat discrete, well-defined anatomical ...
The deterministic effects that can lead to acute radiation syndrome only occur in the case of high doses (> ~10 rad or > 0.1 Gy) and high dose rates (> ~10 rad/h or > 0.1 Gy/h). A model of deterministic risk would require different weighting factors (not yet established) than are used in the calculation of equivalent and effective dose.
Absorbed dose is a dose quantity which represents the specific energy (energy per unit mass) deposited by ionizing radiation in living matter.Absorbed dose is used in the calculation of dose uptake in living tissue in both radiation protection (reduction of harmful effects), and radiology (potential beneficial effects, for example in cancer treatment).