A CAT scan is a painless and non-invasive exam that enables various structures of the human body to be analysed, by producing axial images that can be reconstructed from multiple angles, providing different perspectives and therefore a more accurate assessment. This is one of the diagnostic exams that currently allows for a more comprehensive, rapid and detailed view of multiple organs. Find out how it is performed and when it is recommended.
What is Computed Tomography?
A CAT scan is an imaging exam that uses X-rays to visualise and assess organs in a specific area of the body. Images are obtained from various angles and in different planes, creating multiple, extremely fine (less than 1 mm) cross-sectional “slices” that are then processed by computer, reconstructing images that enable different structures of the body, such as bones, parenchymal organs and blood vessels, to be viewed and analysed far more effectively than with conventional X-rays.
Therefore, computed tomography provides much more detailed images than conventional X-rays, whose resolution in limited because the different structures of a certain region are superimposed on a single image.
In many cases, CT provides enough information to inform diagnosis and clinical decisions, by allowing disorders to be characterised, narrowing the range of possible diagnoses and providing more accurate indications of any other exams that may be required. In certain cases, a CAT scan can even be sufficient to obtain a final diagnosis, making it possible to avoid other more invasive diagnostic methods.
How is Computed Tomography performed?
CAT scans usually involve the following steps:
1. Patients should wear a hospital gown and remove all metallic objects.
2. Next, they lie on a table that slides through a donut-shaped scanner.
3. The scanner rotates around the body as it emits X-rays, obtaining detailed images of the area being studied. To guarantee image quality, it is crucial for the patient to remain still.
4. The technical team monitors the patient continuously, staying in constant contact and providing instructions whenever necessary. This exam is quick, usually lasting around 10 minutes (duration can vary depending on the study).
5. The CAT scan can be performed with or without contrast material (usually iodine-based), which is administered orally and/or intravenously. This dye provides a more detailed view of the organs and better characterisation of lesions.
6. After the exam, the images are analysed by a physician, who produces a report providing an interpretation of the results.
While they are usually safe, contrast media can cause side effects, which in most cases are mild and self-limiting. In certain situations, preventive medication may be required. The use of contrast material should always be assessed by the physician, as it may not be recommended for patients with severe renal insufficiency, pregnant women, or people with a history of moderate to severe allergic reactions.
