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Medical Radiation: A Basic Understanding

The Role of Medical Radiation

There was a time when the only way a physician could look inside a patient was through the most direct route available—invasive surgery. Today, physicians turn to advanced medical imaging procedures, such as computed tomography (CT), PET/CT, interventional radiology, and image-based surgical procedures to aid in the early detection, diagnosis and treatment of cancer, cardiovascular, neurological disease, and other health conditions.

As a result of earlier and improved diagnosis, survival has increased, recovery times have decreased, and overall quality of patient care has improved.1 Most of us can look to our own experiences as proof of the value of medical imaging:

  • A visit to the emergency room where a CT scan allowed the physician to make a diagnosis of acute appendicitis
  • A grandfather's PET/CT scan that helped identify major reductions in blood flow to his heart
  • A mother or sister's interventional procedure to decrease the pain associated with her uterine fibroids
  • A father, aunt, cousin or colleague whose virtual colonoscopy scan identified a pre-cancerous polyp

The examples above describe the importance of imaging procedures that use radiation. But some imaging procedures such as ultrasound and magnetic resonance imaging (MRI) do not involve radiation. So why is radiation necessary for some procedures and not others?

The answer lies in the technology. Various imaging methodologies, such as CT scans, MRI, nuclear medicine scans, and ultrasound, generate images in different ways. X-rays were one of the first ways to see inside the human body, and the technology remains valuable today.

CT scans use a series of X-rays that are reconstructed into multi-dimensional images with crisp anatomical detail. MRI devices use the force of a powerful magnet to momentarily realign hydrogen molecules in the body, forming an image captured by a computer. Nuclear medicine scans use radioactive materials (radiopharmaceuticals) taken orally or by injection. These radiopharmaceuticals are chosen based on their ability to localize in a specific organ and emit signals that indicate how that organ is functioning. An ultrasound machine uses sound waves that penetrate the body. When these sound waves encounter various structures, they send echoes back to the machine, which are recorded as an image.

Determining which imaging method is the best one to use in any particular circumstance is based on a number of factors, including the clinical status of the patient, the goal of the imaging study, the level of detail needed and whether anatomical information is sufficient or if functionality is also necessary. These are just a few of the considerations that enter into the decision-making process when a physician or other healthcare provider orders an imaging procedure.

Medical professionals and their patients should discuss treatment goals and options to decide on the appropriate imaging technique.

medical radiation scans

For many years, GE Healthcare has been at the forefront of technologies designed to help physicians see more clearly so they can diagnose and treat more accurately. During that time, we've remained committed to the idea of the right image using the right amount of radiation, for the benefit of the patient.

GE Healthcare wants you to know more about the benefits and potential risks of radiation used in medical imaging. By supporting informed decisions that are based on both the benefits and the risks, we are working to help ensure that medical imaging can and will continue to be an appropriate, powerful tool in the detection, diagnosis, and treatment of illness and disease.


  1. Lichtenberg FR. The quality of medical care, behavioral risk factors, and longevity growth. Int J Health Care Finance Econ. 2011;11:1-34.