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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 scans can expose patients to levels of radiation 100-500 times higher than traditional x-rays, with higher radiation doses producing better resolution imaging. [37] While easy to use, increases in CT scan use, especially in asymptomatic patients, is a topic of concern since patients are exposed to significantly high levels of radiation. [36]
CT images of the head are used to investigate and diagnose brain injuries and other neurological conditions, as well as other conditions involving the skull or sinuses; it used to guide some brain surgery procedures as well. [2] CT scans expose the person getting them to ionizing radiation which has a risk of eventually causing cancer; some ...
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]
A CT scan is typically performed after radiographic contrast media (dye) has been placed with fluoroscopic guidance into a sac-like lining (the first- and hardest and outermost- layer of the spinal meninges, the spinal dura mater) surrounding the spinal cord and nerves. The material is typically water-soluble, which has largely replaced ...
Radionuclide cisternography may be used to diagnose a spinal cerebrospinal fluid leak. CSF pressure is measured and imaged over 24 hours. [2] A radionuclide (radioisotope) is injected by lumbar puncture (spinal tap) into the cerebral spinal fluid to determine if there is abnormal CSF flow within the brain and spinal canal which can be altered by hydrocephalus, Arnold–Chiari malformation ...
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.
When an exposure is made, X-ray radiation exits the tube as what is known as the primary beam. When the primary beam passes through the body, some of the radiation is absorbed in a process known as attenuation. Anatomy that is denser has a higher rate of attenuation than anatomy that is less dense, so bone will absorb more X-rays than soft tissue.