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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 ...
Doctor reviewing a radiation treatment plan. In radiotherapy, radiation treatment planning (RTP) is the process in which a team consisting of radiation oncologists, radiation therapist, medical physicists and medical dosimetrists plan the appropriate external beam radiotherapy or internal brachytherapy treatment technique for a patient with cancer.
The improvement to DXA with DXL is that, for each pixel scanned by DXA, the exact thickness of the measured object is also measured using lasers. The DXL results allow for a more accurate estimation of bone density by using three separate inputs (low and high x-ray energies plus thickness) rather than two for each pixel in the measuring region.
In modern radiation therapy, 3D dose distributions are typically created in a computerized treatment planning system (TPS) based on a 3D reconstruction of a CT scan. The "volume" referred to in DVH analysis is a target of radiation treatment, a healthy organ nearby a target, or an arbitrary structure.
Radiofrequency Echographic Multi Spectrometry (REMS) is a non-ionizing technology for osteoporosis diagnosis and for fracture risk assessment. REMS processes the raw, unfiltered ultrasound signals acquired during an echographic scan of the axial sites, femur and spine. The analysis is performed in the frequency domain.
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]
External beam radiation therapy (EBRT) is a form of radiotherapy that utilizes a high-energy collimated beam of ionizing radiation, from a source outside the body, to target and kill cancer cells. The radiotherapy beam is composed of particles, which are focussed in a particular direction of travel using collimators. [ 1 ]
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.