The concept of Computerized tomography helps in capturing the images through x-rays of internal body structure and organs. For the examination of internal structure of the body, the technology uses conventional x-ray system. It has two limitations that include:
- Three-dimensional information is superimposed on a single plane that allows the creation of diagnosis confusion which is very difficult.
- The photographic films are used for creating radiographs that have limited dynamic range and these objects have large variations in the absorption of x-rays that are relative to the surroundings that cause contrast differences on the film. The details of bony structures are seen with the shape and composition of accurate soft tissue organs.
The CT Scanning technologies make use of special x-ray equipment that helps to obtain the data of the image from various different angles around a human’s body. Later, it will show a cross-section of body organs and tissues. Also, it is able to show various types of soft tissues, lung-tissues, bone or blood vessels. It is considered as a patient friendly exam that makes the involvement of little radiation exposure.
In this process, the image is reconstructed from various abnormal profiles that are considered on regular angular intervals around a slice. Each of the profile is made from parallel set that have absorbed values through the subject. It results in scanning throughout the body of the patient, but the method of detection is electronic in nature and the data is directly transformed from analog signal to digital impulses in a special AD Converter. The representation of digital platform increases the intensity and is fed into the computer which are reconstructed an image.
The tomography method makes use of an x-ray detector which helps in the translation of linear track across the x-ray beam. When the end of the scanning will reached to the end of x-ray tube, the detector will be rotated to a new angle and the liner motion is repeated constantly. The recent development in CT machines with the advancement uses ‘fan beam’ geometry with an array of detectors that determines or identifies number of different paths through the patient.