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An illustration of the heel effect in an x-ray tube. In X-ray tubes, the heel effect or, more precisely, the anode heel effect is a variation of the intensity of X-rays emitted by the anode depending on the direction of emission along the anode-cathode axis. X-rays emitted toward the anode are less intense than those emitted perpendicular to ...
Dual-energy X-ray absorptiometry is the most widely used and most thoroughly studied bone density measurement technology. The DXA scan is typically used to diagnose and follow osteoporosis , as contrasted to the nuclear bone scan , which is sensitive to certain metabolic diseases of bones in which bones are attempting to heal from infections ...
However, there are two exceptions: firstly, the GSV collaterals (the veins that run parallel) drain the abdominal wall and have a flow from top to bottom so that, when an examiner tests the saphenofemoral junction, a false-positive diagnosis might be made; secondly, in the flow from the sole of the foot venous network, around 10% drains to the ...
The x-ray tube was removed to render the apparatus harmless before being put on public display, due to the possible risk of radiation burn or other health problems if it were switched on. The risk of radiation burns to extremities was known since Wilhelm Röntgen 's 1895 experiment, but this was a short-term effect with early warning from ...
In conventional CT machines, an X-ray tube and detector are physically rotated behind a circular shroud (see the image above right). An alternative, short lived design, known as electron beam tomography (EBT), used electromagnetic deflection of an electron beam within a very large conical X-ray tube and a stationary array of detectors to achieve very high temporal resolution, for imaging of ...
Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object.Applications of radiography include medical ("diagnostic" radiography and "therapeutic radiography") and industrial radiography.
Electron beam computed tomography (EBCT) is a fifth generation computed tomography (CT) scanner in which the X-ray tube is not mechanically spun in order to rotate the source of X-ray photons. This different design was explicitly developed to better image heart structures that never stop moving, performing a complete cycle of movement with each ...
X-ray computed tomography (CT), or Computed Axial Tomography (CAT) scan, is a helical tomography technique (latest generation), which traditionally produces a 2D image of the structures in a thin section of the body. In CT, a beam of X-rays spins around an object being examined and is picked up by sensitive radiation detectors after having ...