PET, MRI, X-ray, and CT are imaging techniques that provide images that doctors use to search for particular anatomical conditions of a patient.

PET Scans use positively charged anti-electrons to identify metabolically active areas in that body that may indicate cancer. Often, PET is combined with CT to provide precise imaging for areas that have high metabolic activity.

The radioactive sugar injected in patients during PET scans decays in the body while releasing positrons. This can expose the body to more ionizing radiation.

CT scans are computed tomograms that use different x-rays simultaneously to provide images of the body, including bones and tissues, when trying to identify disease. The images are taken by moving the scanner around an individual. They are then reconstructed on a computer screen to give a much better look at the sites with defects.

X-rays use high energy electromagnetic ways to find disease. The waves travel and get absorbed by different body structures. X-rays are not able to move well through the bones; they help doctors to see changes in bones when there is a contrast with the soft tissues. Soft tissues have minimal contrast with each other, making x-ray not useful when imaging soft tissue.

CT scans and X-rays use ionizing radiation, which in high doses can damage the body. X-rays use small doses of ionizing radiation in a single dose. A contrast agent is orally given to the patient or injected intravenously to help improve the imaging. Modern CT scans work fast and offer detailed information for different conditions to the radiologists.

MRI scans use magnetic waves to provide better resolutions of soft tissues like the brain. This procedure does not use radiation, making it a safer imaging option compared to a CT scan or X-ray. The patient may need to take an intravenous contrast. MRI scans are slow and may cause claustrophobia in some patients when they stay in the scanner for long. Some machines are very loud during the procedure.

All four techniques are used in oncology to determine the size, location, and behavior of tumors in the patient’s body. They can help doctors determine treatment options for every patient’s condition. PET-CT scans can be used to monitor treatment and determine if a patient’s cancer has healed or recurred.