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The radiation dose of current DEXA systems is small, [24] as low as 0.001 mSv, much less than a standard chest or dental x-ray. [25] [26] However, the dose delivered by older DEXA radiation sources (that used radioisotopes rather than x-ray generators) could be as high as 35 mGy, [27] [28] [29] considered a significant dose by radiological ...
DXA is only able to provide the areal bone mineral density. High-resolution peripheral quantitative computed tomography (HR-pQCT) is better than DXA at detecting bone microarchitecture, modeling whole-bone geometry using 3-dimensional information from scans. This method allows estimation of bone strength and other mechanical properties. [20]
The standard in bone mineral density scanning developed in the 1980s is called Dual X-ray Absorptiometry, known as DXA. The DXA technique uses two different x-ray energy levels to estimate bone density. DXA scans assume a constant relationship between the amounts of lean soft tissue and adipose tissue.
Iodinated contrast contains iodine.It is the main type of radiocontrast used for intravenous administration.Iodine has a particular advantage as a contrast agent for radiography because its innermost electron ("k-shell") binding energy is 33.2 keV, similar to the average energy of x-rays used in diagnostic radiography.
A bone scan or bone scintigraphy / s ɪ n ˈ t ɪ ɡ r ə f i / is a nuclear medicine imaging technique used to help diagnose and assess different bone diseases. These include cancer of the bone or metastasis , location of bone inflammation and fractures (that may not be visible in traditional X-ray images ), and bone infection (osteomyelitis).
It is not used for bone imaging, as the image quality is not good enough to make an accurate diagnostic image for fractures, inflammation, etc. It can also be used to measure total body fat, though this is not common. The radiation dose received from DEXA scans is very low, much lower than projection radiography examinations. [citation needed]
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]
The expensive and potentially dangerous radioactive sources used in SPA and DPA have been replaced by single X-ray absorptiometry (SXA) and dual-energy X-ray absorptiometry (DXA) since the late 1980s. Similar to DPA, the basic principle of DXA is to measure the high and low energy X-ray transmission of stable X-ray sources.