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The history of X-ray computed tomography (CT) dates back to at least 1917 with the mathematical theory of the Radon transform. [ 1 ] [ 2 ] In the early 1900s an Italian radiologist named Alessandro Vallebona invented tomography (named "stratigrafia") which used radiographic film to see a single slice of the body.
The risks of CT scan radiation are especially important in patients undergoing recurrent CT scans within a short time span of one to five years. [ 157 ] [ 158 ] [ 159 ] Some experts note that CT scans are known to be "overused," and "there is distressingly little evidence of better health outcomes associated with the current high rate of scans."
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 ...
Computed tomography or CT scan (previously known as CAT scan, the "A" standing for "axial") uses ionizing radiation (x-ray radiation) in conjunction with a computer to create images of both soft and hard tissues. These images look as though the patient was sliced like bread (thus, "tomography" – "tomo" means "slice").
MRI Scanner Mark One. The first MRI scanner to be built and used, in Aberdeen Royal Infirmary in Scotland. The history of magnetic resonance imaging (MRI) includes the work of many researchers who contributed to the discovery of nuclear magnetic resonance (NMR) and described the underlying physics of magnetic resonance imaging, starting early in the twentieth century.
Image from a CT scan of the brain. CT imaging uses X-rays in conjunction with computing algorithms to image the body. [7] In CT, an X-ray tube opposite an X-ray detector (or detectors) in a ring-shaped apparatus rotate around a patient, producing a computer-generated cross-sectional image (tomogram). [8]
A typical 3D data set is a group of 2D slice images acquired, for example, by a CT, MRI, or MicroCT scanner. These are usually acquired in a regular pattern (e.g., one slice every millimeter) and usually have a regular number of image pixels in a regular pattern.
Tomographic systems have significant variability in their applications and geometries (locations of sources and detectors). This variability creates the need for very specific, tailored implementations of the processing and reconstruction algorithms. Thus, most CT manufacturers provide their own custom proprietary software.