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A Guide to Medical Imaging

It wasn’t so long ago that diagnosing a pulmonary embolism required an invasive procedure that could take more than an hour. “Imagine, having to undergo a procedure with significant risk of complication just to find out if you have an embolism,” commented Threasa Frouge, MD. “Today, you can schedule a pain-free CT scan that can rule out an embolism as well as provide details about the other structures within the scan area. The procedure time for a CT scan is less than 15 minutes.”

Threasa Frouge, MD, is a Banner Health radiologist. Beth Allen is director of clinical operations at Banner Imaging. The two have worked together for more than 30 years. When we spoke with them, they explained the leaps and bounds that their field has taken over the last decades.

“Innovations in imaging are advancing so quickly. We see many patients finding issues that they didn’t even know to look for,” said Allen. “The depth of detail found in our imaging is astounding. As our technology gets more sophisticated, we can get an even more complete understanding of health, with little to no risk to the patient.”

Imaging is an important field where we are seeing research and innovation skyrocket. If you have been recommended for imaging, you may be wondering what that experience will be like, what your doctor will be looking for and what, if any, risks you should consider.


X-rays have been used in a clinical setting for more than 120 years. An energy beam passes through the body. Bones and tissues will block some of the energy to create a picture of what is inside.

  • Advantages: Traditional X-ray is non-invasive, quick and comfortable.
  • Disadvantages: X-ray scans use small amounts of radiation, which can damage cells and increase your risk for cancer. This is a minor dosage. It is believed that one chest X-ray exposes you to the same amount of radiation as a flight across the Atlantic Ocean.
  • Common Uses: To detect broken bones, some cancers and infections.

Computed Tomography (CT Scan)

CT Scans use X-rays to create a three-dimensional view of the body. Beams rotate around the patient to capture multiple angles and get a better picture of internal organs and bones. Patients lie still on a bed and pass through a ring containing the scanner. You may be asked to put your arms above your head for torso scans.

  • Advantages: The scan can take as little as one minute to complete. Doctors and radiologists can see in and around areas in your body to detect subtle indicators and risks.
  • Disadvantages: Produces slightly higher amounts of radiation than X-rays, although still a very small amount.
  • Common Uses: To collect more detailed images of bones, organs, the brain and more.

Magnetic Resonance Imaging (MRI Scan)

The patient lies on a bed, which slides into a narrow tube for the scan. An MRI scan uses magnets and radio waves to create a reaction in fluids within the body. The machine reads the reactions within the body to create a three-dimensional image of soft tissues and can even detect movement in blood flow and organ function.

  • Advantages: MRI scans are extremely effective in soft tissue scans. The scan uses non-ionizing radiation, which is an advantage over X-ray and CT Scans.
  • Disadvantages: The process can be lengthy, and patients have been known to feel claustrophobic. However, MRI now offers a much larger bore or scanning area and imaging is much faster than in the past, alleviating the occasional anxiety. The scan requires the patient to lie very still, which makes MRI difficult for children without the use of general anesthetic.
  • Common Uses: Soft tissue scans, organs, cartilage and ligaments.

Positron Emission Tomography (PET Scan)

A radioactive tracer is administered to the patient prior to the scan. Like the CT and MRI scans, the patient lies on a bed for a PET scan, which slides through a tube. The scan detects the tracer’s interactions within the body.

  • Advantages: This scan is excellent for detecting early signs of illness. The tracer often includes sugars, which are attracted to areas within the body where rapid growth is occurring. This is particularly effective in detecting and monitoring cancer.
  • Disadvantages: The tracer includes ionizing radiation, which can lead to cancer. However, most patients undergoing a PET Scan are undergoing cancer treatment, lessening the concern for caner induction. Like the MRI scan, patients are required to hold still for an extended time.
  • Common Uses: Detecting cancers and abnormal activity in the body.


Ultrasound imaging projects high-frequency sound waves into the body that bounce back to show a live view of the organs, soft tissues and bones within the body. Ultrasound with Doppler is used to evaluate arteries and veins throughout the body.

  • Advantages: This scan is usually non-invasive, painless and produces a live view. It requires no exposure to ionizing radiation. It is effective in viewing organs, like the heart, in motion.
  • Disadvantages: Contents of the body, such as air and water, can affect the image results. This may require patients to fast prior to a scan. Image quality depends greatly on the skill of the person performing the scan.
  • Common Uses: Monitoring babies during pregnancy, observing organs and structures in the neck, abdomen and pelvis.

Imaging is used in more ways than ever. It is informing doctors of abnormal activity and helping ensure that patients receive the right treatment the first time. If you are nervous about a scan, speak with your doctor or specialist to learn why the scan was recommended and what you should expect on the day of your scan.

Some patients can feel apprehensive about certain scans, especially if those scans include exposure to ionized radiation. To those people, Dr. Frouge offered some reassurance. “We don’t use imaging techniques unless we feel strongly that they are needed. Any exposure to radiation can be dangerous, but we want to ensure everyone that this is a very low dosage. You should never put off an examination because you fear the radiation. Whatever we are scanning for is likely much more dangerous than the low dose of radiation you will receive. From my decades of experience, I can say with confidence that, when recommended by your doctor, scanning is the safe thing to do.”

Learn more about how Banner Health Is leading the way in innovation and cutting-edge capabilities in imaging and radiology.

Imaging Innovation