An imaging test helps health care providers better understand what may be wrong with you so they can make treatment decisions or rule out certain health problems.
There are many different types of imaging tests, so it’s easy to get confused about how they work or when they’re used.
“Doctors have a range of options when it comes to imaging tests,” says Dr. Evelyn Y. Anthony, professor and chair of the department of radiology at the University of Florida College of Medicine, UF Health Shands in Gainesville, Florida. “In general, we want to use the simplest and least expensive test that will provide the information needed for treatment.”
Here’s more information about the different types of commonly ordered imaging tests.
[READ: Health Questions to Ask Your Doctor]
X-Ray Imaging Uses and Risks
X-rays use a type of electromagnetic energy to get a picture of what’s going on inside the body. This helps healthcare professionals to see the bones, organs and tissues.
An X-ray is used most often to diagnose conditions such as:
— Fractures
— Tumors
— Breast cancer, with the use of a mammogram
Pregnant women are generally advised to avoid X-rays because the quickly developing unborn baby is at greater risk from any radiation harm. Although the amount of radiation exposure from an X-ray is low for adults, it’s still good to talk to your provider about any concerns you have about that exposure.
[SEE: Health Screenings You Need Now.]
CT Scan Uses and Risks
A CT scan (computed tomography scan) blends X-ray and computer technology so health care professionals can see bones, organs, muscles and other parts inside the body. It provides more information than X-rays alone. The scan is taken by moving an X-ray beam around the body in a circular motion.
A CT scan is most commonly used for:
— Injuries
— Certain types of biopsies
— Internal bleeding
— Tumors
Some CT scans are performed with contrast. Contrast is a special dye taken orally or via injection to show the area being studied more clearly.
Often, health care providers will combine different types of imaging. For instance, they may have an X-ray done to view an ankle injury but then use a CT scan to see the details of a more complex fracture, Anthony explains.
Talk to your health care provider about possibly avoiding a CT scan if you:
— Have kidney problems, as some types of contrast used with a CT scan may lead to kidney failure or
— Are pregnant
You likely can still have a CT scan with contrast if you’re allergic or sensitive to iodine or shellfish. This is an area of concern because of the ingredients in contrast, but more recent findings have debunked this myth.
Although children can have X-rays, their providers should stay aware of the radiation dose associated with exams like X-ray and CT, says Dr. Vishal Patel, a board-certified radiologist at Stony Brook Medicine in Stony Brook, New York. That’s because too much radiation exposure can raise the risk for certain types of cancer. Your child’s provider can help address the benefits versus risks of imaging tests depending on the reason for having the test.
[Related:Health Screening Tests Every Woman Should Have]
MRI Uses and Risks
Magnetic resonance imaging is able to show clear images of everything inside your body, including bones, muscles and organs. Unlike X-rays, MRIs can provide a detailed view of soft tissue areas like the cartilage, ligaments and tendons.
An MRI is done with the use of a very big magnet and radio waves. It’s commonly used for:
— Abscesses
— Infections
— Cancer of the brain, spinal cord, breast, prostate, uterus and in some cases, liver
A CT scan, MRI or ultrasound can use two-dimensional (2D) or three-dimensional (3D) imaging. Three-dimensional imaging provides a more detailed view of what’s inside the body.
“3D images help surgeons and radiologists understand the abnormal alignment of bones and how to best plan the surgery. Patients appreciate the simplicity of seeing their imaging test with 3D images,” Patel says.
However, 3D imaging often costs more than regular 2D imaging. Before having an MRI, talk to your healthcare provider if you:
— Are claustrophobic (you may be able to take a medication to relax you or have an open MRI versus a closed MRI)
— Are pregnant
— Are allergic to the contrast dye sometimes used with an MRI
— Have any type of metal in your body, including pins, screws or implants
— Have a pacemaker or cochlear implant
PET Scan Uses and Risks
A PET (positron emission tomography) scan can help detect disease with a radioactive substance referred to as a tracer. A health care provider will deliver the tracer through an IV inserted into one of your veins. Nowadays, machines often combine PET and CT technology for more effective imaging.
A PET scan is commonly used to detect:
— Cancer
A PET scan is an example of nuclear medicine, which uses small amounts of radioactive material to diagnose or treat problems.
Those who are pregnant or breastfeeding are generally advised to avoid PET scans, as are those who are allergic to the tracer material used with a PET scan.
Ultrasound Uses
Ultrasound involves using high-frequency sound waves to take pictures of your organs or other areas of the body, including your blood vessels. Other names for ultrasound are sonography or ultrasonography.
Ultrasound is often associated with pregnancy, since it’s used to generate a “picture” of the fetus. However, ultrasounds are also used to check for problems in specific areas of the body.
“Ultrasound is a great modality for seeing structures that are relatively close to the skin surface,” Anthony says. This may include the:
— Gallbladder
— Heart
— Kidneys
Tips for Imaging Tests
There are a few things you can do to get the most out of your imaging test.
— Make sure you’re clear on the purpose of the imaging test and what will happen during the test. This should be something your health care provider explains to you clearly, says Dr. Arun Krishnaraj, chair of the Commission on Patient and Family Centered Care for the American College of Radiology. If not, contact the radiology department where you will have the imaging done and ask if someone can explain it to you. You can also visit the website RadiologyInfo.org, which provides information from the American College of Radiology.
— If you can’t have one type of imaging test, find out what other options are available. Often, there’s an alternate imaging test available if you have to avoid a first choice, Krishnaraj says.
— Ask how you should prepare for your imaging test. “Some tests may have no instructions, and some tests may require a special diet or a short fasting period so that ultimately, the best images are obtained,” Patel says. For MRI tests, you’ll need to wear clothing without metal, so no zippers or buttons.
— If you have insurance, find out if the imaging test is covered. “Patients with insurance should proactively confirm coverage for recommended imaging tests to avoid unexpected costs and ensure a smooth process,” says Emmanuel B. Thomas, department administrator of radiology at Stony Brook Medicine in Stony Brook, New York. Typically, a staff member within the radiology office will obtain a preauthorization, meaning they will confirm whether your insurance plan will cover some or all of the imaging test. If you don’t have insurance, let your healthcare provider or the imaging center know. “These patients can explore options such as financial assistance, payment plans and government programs such as Medicaid,” Thomas says.
— If you’re going to an imaging site at a large location, like a hospital, ask for directions on how to get there. “For large complexes, radiology areas may be harder to find than you think,” Anthony says. “The equipment has specific safety needs and may be located separately from offices and clinics.”
— Let your health care provider know if you have additional imaging tests coming up scheduled by another health care provider. In this case, providers may decide that only one imaging test is necessary, allowing you to avoid the extra expense and lowering your radiation exposure if the tests involve radiation. “Don’t go through the system passively,” Krishnaraj says. “Be an advocate for yourself, speak up and ask questions.”
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What Is an Imaging Test? originally appeared on usnews.com
