Search results
Results From The WOW.Com Content Network
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 ...
On 1 October 1971, CT scanning was introduced into medical practice with a successful scan on a cerebral cyst patient at Atkinson Morley Hospital in Wimbledon, London, United Kingdom. [16] In 1975, Hounsfield built a whole-body scanner. The principles of computed tomography developed by Hounsfield remain in use today (2022).
The idea for the PET scan was originally proposed by William Sweet in the 1950s, but the first full-body PET scanner wasn't actually developed until 1974 by Michael Phelp. [9] Similarly, the single-photon emission computed tomography scan, or SPECT scan, also works by scanning a tracer within the patient.
The data can be corrected for self-absorption artefacts using an X-ray absorption-contrast CT scan of the same sample. If the solid-state chemistry of the sample is changing during the XRD-CT scan, then other data acquisition approaches can be employed that can improve the temporal resolution of the method, such as the interlaced approach [13] [14]
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Electron beam computed tomography (EBCT) is a fifth generation computed tomography (CT) scanner in which the X-ray tube is not mechanically spun in order to rotate the source of X-ray photons. This different design was explicitly developed to better image heart structures that never stop moving, performing a complete cycle of movement with each ...