Infographic: Different Imaging Tests Explained

Graphic for the different types of tests

Have you ever wondered why there are different types of imaging tests? Or what the differences between the many types of imaging tests are? Learn about the possible modalities and their purposes here.

Different Types of Imaging Tests: Sorting Out the Differences

If your doctor has ordered a medical imaging exam for you, you might have questions about the type of scan or test you will be having. Technologists use modalities (different types) to gather the right images for your radiologist to examine. If you’re getting a scan to see if you have a concussion, for instance, CT would be the modality for your exam. On the other hand, if you are getting a mammogram, X-ray would be the modality in use. 

At UVA Radiology and Medical Imaging, we use each modality to perform multiple types of imaging exams to diagnose multiple kinds of conditions. Each modality is unique in terms of the images it gathers, equipment it uses, and conditions it helps radiologists diagnose. Learn more about our five most common modalities for our various types of imaging tests: X-ray, CT, MRI, ultrasound, and PET.

(Text only version)

An infographic describing different modalities

Infographic Text: What are the modalities?

UVA Radiology and Medical Imaging
X-ray, CT, MRI, Ultrasound, PET
  • X-rays take images that are good for looking at bones and foreign objects in tissues.
  • Equipment: X-ray equipment is either a table with an X-ray machine above the patient, or a stationary X-ray machine that the patient stands in front of for pictures.
  • Conditions diagnosed: fractured bones, common injuries/infection, breast cancer, arthritis, osteoporosis, gastrointestinal problems, bone cancer.
CT Scan:
  • CT scans take detailed images slices of bones, tissues, and blood vessels that are good for staging cancer or tumors and assessing emergency situations.
  • Equipment: a CT scanner looks like a fairly wide tunnel where the images are taken, and a table slides through the tunnel.
  • Conditions diagnosed: injuries from trauma, infections, brain injury (concussions), lung cancer, tumors, vascular diseases, stroke.
MRI Exam:
  • MRIs create detailed 3D images of soft tissues used to diagnose tendon or ligament injury and find spinal cord issues.
  • Equipment: an MRI machine is a tunnel-shaped machine with a table that slides into it. It is larger than the CT scanner, but the tunnel is often narrower.
  • Conditions diagnosed: Multiple Sclerosis, internal bleeding, dementia, tendon injury, joint problems, tumors, prostate cancer, female pelvic problems.
  • Ultrasounds give clear pictures of soft tissues and their movements, and find images of blood flow through vessels.
  • Equipment: ultrasound exams use ultrasound gel applied directly to the patient’s skin and a machine that uses a small probe and a computer screen.
  • Conditions diagnosed: causes of heart attack, causes of pain, swelling, and infection, heart disease, biopsy guidance, prenatal tissues, blood flow issues, blood clots.
PET Scan:
  • PET images capture activity and show how organs and tissues function. They are used to monitor cancer and treatments and coronary artery disease.
  • Equipment: PET scans use a radiotracer that is swallowed or injected. The PET scanner looks like a CT scanner (but doesn’t give its own radiation; it just reads the radiation from the radiotracer).
  • Conditions diagnosed: Alzheimer’s disease, cancers, epilepsy, Parkinson’s disease, other memory issues, cardiac issues, issues with past treatments.
Source of Power:
  • Radiation
    • X-rays use ionizing radiation
    • PETs read radiotracers inside your body
    • CTs use ionizing radiation
  • Non-radiation
    • MRIs use magnetic waves
    • Ultrasounds use sound waves
Which Scan?
  • Brain and neural system: PET, MRI, CT
  • Heart, lungs, chest: CT, X-ray, MRI, PET, Ultrasound
  • Abdomen and internal organs: Ultrasound, MRI, CT, X-ray, PET
  • Tissues: MRI, PET, Ultrasound
  • Bones: X-ray, CT
Average Duration of Scan:
  • CT: 10 minutes
  • X-ray: 10-15 minutes
  • Ultrasound: 30 minutes – 1 hour
  • MRI: 45 minutes – 1 hour
  • PET: 1.5 – 2 hours
  • *These are the AVERAGE times of the scan and do not account for time spent checking in, receiving contrast or sedation, or possible recovery time.

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