Search results
Results from the WOW.Com Content Network
Superficial radiation therapy machines produce low energy x-rays in the same energy range as diagnostic x-ray machines, 20–150 keV, to treat skin conditions. [3] Orthovoltage X-ray machines produce higher energy x-rays in the range 200–500 keV. Radiation from orthovoltage x-ray machines has been called "deep" due to its greater penetrating ...
Waters' view (also known as the occipitomental view or parietoacanthial projection) is a radiographic view of the skull. It is commonly used to get a better view of the maxillary sinuses. An x-ray beam is angled at 45° to the orbitomeatal line. The rays pass from behind the head and are perpendicular to the radiographic plate.
Historically conventional external beam radiation therapy (2DXRT) was delivered via two-dimensional beams using kilovoltage therapy X-ray units, medical linear accelerators that generate high-energy X-rays, or with machines that were similar to a linear accelerator in appearance, but used a sealed radioactive source like the one shown above.
Due to the higher ionization density caused by soft X-ray radiation in the tissue, the relative biological effectiveness (RBE) of low-energy X-rays on tumor cells is higher when compared to high-energy X-rays or gamma rays which are delivered by linear accelerators. [15]
Megavolt X-ray (or photon) therapy, which delivered a beam of 25 MeV X-ray photons. The X-ray photons are produced by colliding a high current, narrow beam of electrons with a tungsten target. The X-rays are then passed through a flattening filter, and then measured using an X-ray ion chamber. The flattening filter resembles an inverted ice ...
A linear accelerator (linac) produces x-rays from the impact of accelerated electrons striking a high z target, usually tungsten. The process is also referred to as "x-ray therapy" or "photon therapy." The emission head, or "gantry", is mechanically rotated around the patient in a full or partial circle. The table where the patient is lying ...
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.
Thus, a copper X-ray source with a nickel filter can produce a nearly monochromatic X-ray beam with photons of mostly 154 pm. For medical purposes, X-ray filters are used to selectively attenuate, or block out, low-energy rays during x-ray imaging (radiography). Low energy x-rays (less than 30 keV) contribute little to the resultant image as ...