Search results
Results from the WOW.Com Content Network
The information from a prior CT scan of the patient allows more accurate modelling of the behaviour of the radiation as it travels through the patient's tissues. Different dose calculation models are available, including pencil beam , convolution-superposition and monte carlo simulation , with precision versus computation time being the ...
Most radiation therapy is planned using the results of a 3D CT scan. A 3D scan largely presents a snapshot of the body at a particular point in time, however due to the time of the acquisition, in which the patient is likely to have moved in some way (even if only breathing), there will be an element of blurring or averaging in the 3D scan. [6]
The radiation used in CT scans can damage body cells, including DNA molecules, which can lead to radiation-induced cancer. [148] 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]
“OK so I just got out of my CT scan, mapping — as they call it — for my radiation treatment, and when they said they were gonna tattoo me, I didn’t realize it was actual, real tattoos, so ...
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 ...
SPECT visualized by a MIP of a mouse Types of presentations of CT scans: - Average intensity projection - Maximum intensity projection - Thin slice (median plane)- Volume rendering by high and low threshold for radiodensity.
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.
A helical CT beam trajectory is characterized by its pitch, which is equal to the table feed distance along the scan range over one gantry rotation divided by the section collimation. [9] When pitch is greater than 1, the radiation dose for a given axial field of view (FOV) is decreased compared to conventional CT. At high pitches there is ...