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X-ray motion analysis is a technique used to track the movement of objects using X-rays. This is done by placing the subject to be imaged in the center of the X-ray beam and recording the motion using an image intensifier and a high-speed camera , allowing for high quality videos sampled many times per second.
These images look as though the patient was sliced like bread (thus, "tomography" – "tomo" means "slice"). Though CT uses a higher amount of ionizing x-radiation than diagnostic x-rays (both utilising X-ray radiation), with advances in technology, levels of CT radiation dose and scan times have reduced. [9]
The radiation doses received from CT scans is variable. Compared to the lowest dose X-ray techniques, CT scans can have 100 to 1,000 times higher dose than conventional X-rays. [149] However, a lumbar spine X-ray has a similar dose as a head CT. [150] Articles in the media often exaggerate the relative dose of CT by comparing the lowest-dose X ...
CT is based on the same principles as X-ray projections but in this case, the patient is enclosed in a surrounding ring of detectors assigned with 500–1000 scintillation detectors [13] (fourth-generation X-ray CT scanner geometry). Previously in older generation scanners, the X-ray beam was paired by a translating source and detector.
The physical exam may include observation, evaluation of pulses in the foot, lumbar spine range of motion, and components of a neurological exam. [1] Helpful imaging may include x-rays, CT, CT myelogram, and magnetic resonance imaging (MRI), but MRI is preferred. [1]
Nowadays, MRI has all but replaced myelography. [4] MRI is preferable because injection of contrast medium into the spinal canal is infrequently needed for better images. However, a CT myelogram may be useful for patients who cannot undergo MRI (e.g., those with pacemakers or cochlear implants). CT is preferred when MRI images are limited by ...
At the same time, CT imaging technology progressed rapidly and Genant and Boyd worked with one of EMI's first whole body CT systems in the late 1970s and early 1980s to apply the quantitative CT method to the spine, coining the term "QCT." Genant later published several articles on spinal QCT in the early 1980s with Christopher E. Cann, PhD.
The photo below is of a different gantry rotated to about 45°. The apparatus attached to the left side of the gantry is a cone beam x-ray source, with the x-ray detector on the right side. Prior to treatment, the cone beam x-ray system is used to align the patient's tumor with the radiation. Photo of a gantry turned to an angle of about 45°