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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 ...
Cone-beam spiral computed tomography (CT) is a medical imaging technology that has impacted healthcare since its development in the early 1990s. [1] [2] This technology offers advancements over traditional fan-beam CT, including faster scanning speed, higher image quality, and the ability to generate true three-dimensional volumes, even with contrast-enhancement.
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 ]
Image-guided radiation therapy is the process of frequent imaging, during a course of radiation treatment, used to direct the treatment, position the patient, and compare to the pre-therapy imaging from the treatment plan. [1] Immediately prior to, or during, a treatment fraction, the patient is localized in the treatment room in the same ...
Cone beam computed tomography. Not to be confused with Electron beam computed tomography. Cone beam computed tomography (or CBCT, also referred to as C-arm CT, cone beam volume CT, flat panel CT or Digital Volume Tomography (DVT)) is a medical imaging technique consisting of X-ray computed tomography where the X-rays are divergent, forming a cone.
CT scans give the human body a large dose of ionizing radiation – something the computational phantom was designed to circumvent in the first place. MRI images take a long time to process. Furthermore, most scans of a single subject cover only a small portion of the body, whereas a full scan series is needed for useful data.
An enhancement of virtual simulation is 3-dimensional conformal radiation therapy (3DCRT), in which the profile of each radiation beam is shaped to fit the profile of the target from a beam's eye view (BEV) using a multileaf collimator (MLC) and a variable number of beams. When the treatment volume conforms to the shape of the tumor, the ...
The radiation used in CT scans can damage body cells, including DNA molecules, which can lead to radiation-induced cancer. [147] 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. [148]