CT scan
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CT physics course given at KAUH under RSSA in 2008
WHY CT IS USED?
Limitation of radiography and tomography techniques:
•The disadvantage of radiography is the superimposition of all structures on the film (Projection of 3D anatomic information on 2D film). This makes it difficult and sometimes impossible to distinguish a particular detail.
•This becomes even more of a problem if the structures differ only slightly in density e.g. the tumor and tissues in which they are located.
•The problem of superimposition can be overcome somewhat by tomography, in which both the X-ray tube and film move simultaneously in opposite directions so unwanted sections can be blurred (visible as ghosts) while the desired layer or section remains (kept in focus).
•The goal of tomography is to eliminate structures above and below the focused section (focal plane), which is difficult to achieve (image blurring that can not be completely removed).
•Another limitation of tomography is degradation of image contrast due to presence of scattered radiation from the open geometry of the X-ray beam
CT AGE FOR
1.Minimizing the problem of superimposition
2.Improving the contrast of the image, by finding a way to record very small differences in tissue contrast
A computerized axial tomography scan is more commonly known by its abbreviated name, CAT scan or CT scan. It is an x-ray procedure which combines many x-ray images with the aid of a computer to generate cross-sectional views and, if needed, three-dimensional images of the internal organs and structures of the body. A CAT scan is used to define normal and abnormal structures in the body.
Physics and mathematics involved in CT …
The technology refer to the practical implementation of scientific and engineering principles. Including computer science.
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آخر تحديث
5/17/2009 10:54:21 AM
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