A CAT scan, also known as a CT scan or computerized tomography scan, is a type of X-ray that gives you cross-section images of internal structures in the body. Normal X-rays produce an image that lays all components on top of each other, making it difficult to pinpoint the exact location of any abnormality. This is what makes the CT scan such a valuable diagnostic tool. Understanding your CT scan requires understanding of what should be there and what is an abnormality.
Determine what you are looking at on the CT scan films. Your CT scan results will come on an X-ray film and should have the patient name, age and date of the scan printed on each film. Also printed on the CT scan film is information regarding the orientation of the subject in the scan. This is important because it tells you whether you are looking at the right or left side, posterior or anterior view as well as marker scales (which may be as small as millimeters). The film should also let you know if any contrast agents were used to further identify abnormalities.
Search the images for abnormalities. If you are unfamiliar with anatomical structures of the region you are reviewing, it helps to have an anatomy book or a healthy scan to cross-reference against. The scan film may have up to 30 images on it, moving from cross section to cross section. Within each section you are looking for signs of abnormal shapes and sizes, asymmetrical regions, and unusually bright and dark areas. These may represent tumors, lesions or other damage.
Determine the location of the abnormality. By using a site such as NeuroSurvival.ca you can match the slide with the anatomical region showing an abnormal result.
Analyze the results. List any abnormalities you see and measure them with the marker on the right side of the slide. Confirm the effects of any contrast enhancements and rule out any technical issues that may have caused the image abnormality. Bright spots may be fat deposits or tumors. Dark spots represent lesions and damage.