Cat scan

Template:Infobox medical imaging Computed Tomography (CT), commonly referred to as a CT scan or CAT scan (Computerized Axial Tomography), is a medical imaging procedure that uses computer-processed combinations of multiple X-ray measurements taken from different angles to produce tomographic (cross-sectional) images (virtual "slices") of specific areas of a scanned object, allowing the user to see inside the object without cutting.

History

The development of CT was primarily attributed to the work of Godfrey Hounsfield and Allan Cormack, who shared the Nobel Prize in Physiology or Medicine in 1979 for their contributions. Hounsfield developed the first CT scanner at EMI Laboratories in England in the early 1970s, and Cormack provided the mathematical technique of reconstruction.

Principle

CT scanning is based on the X-ray principle: as X-rays pass through the body, they are absorbed at different rates in different parts of the body. A computerized reconstruction algorithm processes the data to produce a 3D image, which can be further manipulated to show various bodily structures based on their ability to block the X-ray beam.

Procedure

During a CT scan, the patient lies on a bed that slides through a large, circular opening of the scanning machine. The X-ray tube and electronic X-ray detectors rotate around the patient, with each rotation producing a slice of the scanned area with great detail. The multiple images taken during a CT scan can be digitally stacked together to form a three-dimensional image.

Applications

CT scans are used in many fields of medicine, including:

• Diagnostic imaging to detect disease or injury within various body parts.
• Planning and guiding certain procedures, such as cancer treatment.
• Diagnostic tests in emergency medicine.
• Surgical planning and diagnosis in complex anatomies.

Risks

While CT scans are an invaluable diagnostic tool, they do expose patients to higher levels of ionizing radiation compared to regular X-rays. This exposure can slightly increase the probability of developing cancer over a person’s lifetime. Therefore, the use of CT scans is carefully planned to ensure that the benefits outweigh the risks.

Advancements

Recent advancements in CT technology include higher scan speeds, greater resolution, and reductions in radiation exposure. Innovations such as dual-energy CT can differentiate between materials of similar density but different atomic compositions, enhancing the diagnostic capabilities of CT.

See also

• Magnetic Resonance Imaging (MRI)
• Ultrasound imaging
• Positron Emission Tomography (PET)
• Radiography