Difference between CT scan and PET scan:
Doctors may use CT scans and PET scans for various medical purposes. Let us discuss both of these in detail:
| Aspect | CT Scan | PET Scan |
| Full form | Computed Tomography | Positron Emission Tomography |
| Year of discovery | Discovered in the early 1970s. | Discovered in the mid-20th century, with the first successful PET scan performed in the 1950s. |
| Discovered by | Sir Godfrey Hounsfield and Dr. Allan Cormack | Dr. David E. Kuhl and Dr. Roy H. Hounsfield |
| Principle of Imaging | Utilizes X-rays to create detailed cross-sectional images of anatomical structures. | Injects a radioactive tracer to visualize the metabolic activity and cellular functions within tissues. |
| Purpose of imaging | Focuses on providing high-resolution anatomical images. | Primarily used to display metabolic processes and to detect areas with abnormal glucose metabolism. |
| Radiation Exposure | Involves exposure to X-ray radiation, which can vary. | Also involves radiation exposure due to the radioactive tracer, but the exposure time is limited. |
| Clinical Applications | It is used in the diagnoses of conditions such as fractures, tumors, infections and internal injuries. | It is particularly useful for cancer detection, its staging and monitoring the treatment response. |
| Combined Scans | It is not typically combined with other scans. | It can be combined with CT scans to provide both anatomical and functional information (PET/CT scan). |
| Interpretation of Image | Provides detailed anatomical structures, which need interpretation by a radiologist or medical professional. | Shows areas of increased tracer uptake, indicating higher metabolic activity. It also requires interpretation by specialists. |
| Contrast Agents | Often uses contrast agents (dyes) to enhance the visibility of certain structures. | It does not use traditional contrast agents. It relies on the injected radioactive tracer for imaging. |
| Duration of Procedure | It is generally a quicker procedure that typically performed within a few minutes. | PET scans may take longer due to the time needed for the radioactive tracer to distribute within the body which may usually upto 1-2 hours. |
| Common Uses | This technique is used for diagnosing injuries, infections, vascular diseases, and various internal conditions. | This technique is particularly used in cancer diagnosis, treatment monitoring, and evaluation of neurological disorders. |