What Does a Radiologist Do?

Medically Reviewed by Zilpah Sheikh, MD on February 27, 2024
Written by Matt McMillen, Lori M. King, PhD
7 min read

Radiologists are doctors who look over and interpret pictures of the inside of your body to help diagnose and treat illnesses. These images of the inside of your body are taken by technicians using one or more of the following imaging methods (also called radiology):

  • X-ray
  • CT scan (uses multiple, computerized X-rays to make a picture of your insides)
  • Ultrasound (uses sound waves to make a picture of your insides)
  • MRI (uses powerful magnets to make a picture of your insides)
  • PET scan (uses radioactive particles to make a picture of your insides)
  • Nuclear medicine (uses radioactive tracers to test how your body is working and to diagnose and treat diseases)

 

Your primary doctor may consult with a radiologist as part of your care. In some cases, a radiologist may be your primary doctor.

Radiologist vs. radiographer

Radiologists go to medical school and are doctors, but they don't typically take the images themselves. Instead, they specialize in interpreting the images to make a diagnosis and help guide your treatment.

Radiographers (also called radiologic technologists), take or assist others while they take medical images. They don't go to medical school, so they aren't doctors, but they are highly trained medical professionals. They help doctors give radiation treatments to people with cancer and also prepare individuals for imaging tests.

Yes. A radiologist can be either a medical doctor (MD) or a doctor of osteopathic medicine (DO). Like other doctors, they go to medical school for 4 years. Then, they complete a 4-year residency in radiology. In the U.S., most radiologists are also board-certified by the American Board of Radiology (for those with MDs) or the American Osteopathic Board of Radiology (for those with DOs).

Radiologists may also go into fellowship training to specialize in certain areas, such as:

Diagnostic radiology. This specialty focuses on interpreting images from a range of procedures to diagnose illnesses and injuries and to help guide treatment. Diagnostic radiologists know which of the imaging tests work the best to tell what's causing your symptoms or disorder and how your treatments are going. Your doctor will often consult with a radiologist to determine the type and extent of your illness or injury. They can also help tell how you respond to treatment. For instance, a radiologist will look at your mammogram images for signs of breast cancer. If you've had breast cancer treatment, your radiologist may monitor you with mammograms to see if your cancer has come back.

Interventional radiology. This specialty focuses on diagnosing and treating patients with minimally invasive techniques. Minimally invasive techniques may allow you to avoid surgery and, at times, hospital visits too. Interventional radiologists use imaging tests such as CT, ultrasound, and MRI to guide where treatments go in your body. Such procedures include:

  • Catheter insertion. A catheter is a long, thin tube that's placed in one of your large veins so that you can have a medical procedure and get medication or nutrition. Catheters are also used for dialysis in people with kidney failure.
  • Angiography. During this procedure, dye is inserted into your blood vessels through a catheter, and then X-rays are taken to help find problems with your blood vessels, such as narrowing.
  • Angioplasty. During this procedure, your doctor inserts and inflates a tiny balloon through a catheter. This opens blocked blood vessels.
  • Stent placement. During this procedure, a mesh coil called a stent is placed in your blood vessel to keep it open.
  • Needle biopsy. During this procedure, your doctor removes a tissue sample using a syringe and needle for analysis in a laboratory.
  • Cancer treatment. Your doctor can deliver cancer medicine directly into your body through a catheter or port.

Radiation oncologist. This specialty focuses on treating patients with cancer and other disorders with radiation. They determine whether you will benefit from radiation therapy. If so, they will also decide your best course of treatment. They use energy beams or radioactive particles to, for instance, attack cancer cells while also limiting damage to your healthy cells. They will usually discuss your treatment options and help you understand what's involved, including expected side effects and how to manage them.

Emergency radiology. This specialty focuses on the diagnosis of injuries and trauma, as well as nontraumatic emergency conditions.

Medical physicists. These medical professionals play an important role in radiology. They help make sure the radiology equipment is working safely and well. They also help plan radiation treatment doses and schedules for cancer patients. Medical physicists aren't doctors, but they usually have a master's degree in physics (some have a PhD), and they do 1-2 years of on-the-job training (called a residency) at a hospital so they can get their certification.

Radiologists have several important jobs. As part of their work, they do the following:

  • Make sure you are healthy enough to have any imaging tests
  • Review and interpret the results of imaging tests to diagnose disorders and injuries
  • Consult with your doctor about the tests you should have and recommend other tests if needed
  • Help guide treatment based on imaging test results
  • Evaluate the images and compare the results to other medical tests you've had
  • Treat your disorder with radiation therapy and use imaging test results to guide any treatments you need

Radiologists can help your doctor diagnose and treat a wide variety of health conditions. So, your doctor will call on a radiologist when they need help with imaging or certain specialized treatments.

Some common reasons you might need a radiologist include if you:

  • Have a problem with your muscles or bones, such as a torn muscle or broken bone .
  • Are pregnant and require imaging tests to help diagnose problems with your unborn baby.
  • Need to undergo screening, diagnosis, or treatment for many types of cancer, including lung cancer and breast cancer.
  • Have blocked arteries or other blood vessels that develop due to health conditions, such as atherosclerosis.
  • Have a foreign object in your body. For example, if you have accidentally swallowed a fish or chicken bone or been in an accident where broken glass, wood, gravel, or thorns may have entered your body.
  • Have liver or kidney problems.
  • Have back pain.
  • Have been in an accident or otherwise had trauma.
  • Have uterine fibroids
  • Have a suspected infection, such as pneumonia.

Depending on your procedure, your appointment can take just minutes or last 2 hours or more. You usually don’t need to prepare for your appointment. But some tests may require you to avoid certain foods, medications, and drinks beforehand.

Always tell the radiology office if you’re pregnant or trying to have a baby. X-rays and CT scans use low-dose radiation. Your doctor may want to use a different imaging test if possible in order to avoid exposing your baby to any possible harm.

X-ray. You’ve probably had your teeth X-rayed at your dentist’s. A medical X-ray is just as simple. You lie or stand, positioning yourself as asked. It’s over in minutes. You may get an X-ray after a car accident, or if you have trouble breathing, pneumonia, lung cancer, or other conditions.

CT scan. This gives a more detailed look at your body than X-rays. Beams of X-rays circle your body to view your organs, bones, and other parts from multiple angles. You’ll lie still on a padded table as it slides into a short, open-ended tunnel. Your radiologist may use it to check a complicated bone fracture, internal bleeding, infections, tumor size, and other reasons. For some CT scans, you may need to take a contrasting substance by mouth or IV to make the image clearer.

Ultrasound. It’s best known for taking pictures of babies in their mother’s womb. Ultrasounds use sound waves to help pinpoint heart damage, swelling, infection, tumors, and other things.

MRI. Instead of radiation, MRIs use radio waves and a magnetic field to peek inside your body. They allow your radiologist to better see soft tissue behind or inside your bones. It’s especially useful for scanning your brain and spinal cord, or for torn ligaments or tumors. Let your doctor know if you could be pregnant or if you have any metal parts or electronic implants, such as:

Your technician may be able to adjust the procedure so that you can still get an MRI.

PET scan. It is a type of nuclear medicine imaging. It uses a small bit of radioactive material to examine the inside of your body at the level of molecules. So, PET scans may detect cancer or problems with your heart, brain, nerves, and elsewhere before other imaging tests can. Usually, you’ll need to stop eating and drinking anything other than water several hours before your procedure.

Radiologists have at least 13 years of medical education and training, including 4 years of medical school and another 4 years of on-the-job training called residency. If they choose to specialize, they may spend another 1 or 2 years in a fellowship. Radiologists must keep up with advancing medical knowledge so that they can keep their professional certification to practice medicine.

Radiologists play a vital role in diagnosing and treating illness. They review and interpret imaging tests that give your doctor essential information about your health. You may see a radiologist for lots of different health concerns, including cancer, heart disease, and emergency care.