Components of CT Scan Machine
- 3. The gantry assembly is the largest of these systems. It is made up of all the equipment related to the patient, including the patient support, the positioning couch, the mechanical supports, and the scanner housing. It also contains the heart of the CAT scanner, the x-ray tube, as well as detectors that generate and detect x rays.
- 4. High Voltage Generator X-ray tube Pre Patient Collimator Patient Post Patient Collimator Detector X ray source Pre Patient Collimation Post Patient Collimation X-ray Detector
- 5. • Two types of detectors are used • Scintillation Detectors • Gas Filled Detectors • Scintillation Detectors • Materials Used • Sodium Iodide • Bismuth Germanium Oxide • Cesium Iodide • Cadmium Tungstate Scintillator Crystal Photo Multiplier Detector Rings
- 6. Gas Filled Detectors • Materials Used • Xenon • Krypton • Xenon + Krypton Since 90% of 50 is 45, the output is same. The overall efficiency of both the detectors is same. Gas Filled Detectors Scintillation Detectors Sensitive face: 100% Detection Efficiency: 45% Sensitive face: 50% Detection Efficiency: 90%
- 7. • The DAS consists of the following parts • X-ray photons come on the detector. • The detector detects the intensity in form of current. • The current is converted into voltage. • The analog integrator removes spikes. • The analog signal is converted into digital form. • This signal can now be processed and reconstructed in the computer. Detector Current to Voltage Convertor Pre Amplifier Analog Integrator Analog to Digital Convertor Computer
- 8. • After enough transmission measurements (detector) • Sent to the computer for processing • A software called Fourier Slice Transform is used. • More than 250,000 reconstruction algorithms are used (example: algebraic reconstruction technique) to compute the image.
- 9. • The operating console is the master control center of the CAT scanner. • It is used to input all of the factors related to taking a scan. • Typically, this console is made up of a computer, a keyboard, and multiple monitors. • Often there are two different control consoles, one used by the CAT scanner operator, and the other used by the physician. • The operator's console controls such variables as the thickness of the imaged tissue slice, mechanical movement of the patient couch, and other radiographic technique factors.