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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 ).
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]
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] The amount of energy deposited in human tissue and organs is the basis for the measurements for humans. [4]
The roentgen or röntgen (/ ˈ r ɛ n t ɡ ə n,-dʒ ə n, ˈ r ʌ n t-/; [2] symbol R) is a legacy unit of measurement for the exposure of X-rays and gamma rays, and is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air (statcoulomb per kilogram).
The fundamental quantity is the absorbed dose (D), which is defined as the mean energy imparted [by ionising radiation] (dE) per unit mass (dm) of material (D = dE/dm) [8] The SI unit of absorbed dose is the gray (Gy) defined as one joule per kilogram. Absorbed dose, as a point measurement, is suitable for describing localised (i.e. partial ...
≡ 1 × 10 −10 m: ≡ 0.1 nm astronomical unit: au ≡ 149 597 870 700 m ≈ Distance from Earth to Sun ≡ 149 597 870 700 m [1] attometre: am ≡ 1 × 10 −18 m: ≡ 1 × 10 −18 m: barleycorn (H) = 1 ⁄ 3 in (see note above about rounding) = 8.4 6 × 10 −3 m bohr, atomic unit of length: a 0 = Bohr radius of hydrogen ≈ 5.291 772 ...
A monitor unit (MU) is a measure of machine output from a clinical accelerator for radiation therapy such as a linear accelerator or an orthovoltage unit. Monitor units are measured by monitor chambers, which are ionization chambers that measure the dose delivered by a beam and are built into the treatment head of radiotherapy linear accelerators.
In mammography, mean glandular dose (MGD) is a quantity used to describe the absorbed dose of radiation to the breast.It is based on a measurement of air kerma and conversion factors.