Sarcoma Imaging

To identify sarcoma, you may need tests with scanning machines that produce images of your body. A radiologist will interpret these images to understand the precise location and size of a tumor.


This test may show the extent of disease in the bone.

PET and CT scans

A positron emission tomography (PET) scan is a nuclear imaging test that uses a small amount of radioactive material to highlight areas of suspicious cells. Computed tomography (CT) scans use X-ray technology to take cross-sectional images of the body. We use these technologies alone or combined, depending on the information we need from the scans.

During treatment, our doctors use PET scans alone to:

  • Determine whether cancer has spread to the lymph nodes (small glands that filter bacteria, viruses, cancer cells, and other impurities) or other parts of the body and, if so, where
  • Monitor how well cancer is responding to treatment
  • See if cancer has returned after treatment

We offer combined PET/CT scanning, which takes both scans at the same time and in the same machine to keep you in the same position. This technique allows us to combine CT images of the body with PET scans that highlight possible areas of cancer.

The combined PET/CT images show the specific locations of any cancer, providing more precise information for treatment. We use PET/CT scans to:

  • Stage cancer
  • Check other parts of the body to see if cancer has spread there
  • Monitor cancer’s response to treatment


An ultrasound test uses high-frequency sound waves to create images. Ultrasound does not use radiation and is painless. It can provide clearer images of soft tissues.

Ultrasound can:

  • Show greater detail after other imaging identifies an abnormality
  • Distinguish between different types of tissues, such as fluid-filled cysts and solid masses
  • Help guide a biopsy needle to take a tissue sample and test for cancer


Magnetic resonance imaging (MRI) uses radio waves and a powerful magnetic field to create detailed, cross-sectional pictures of the tumor. MRI does not use radiation.

During the diagnostic process, MRI can help us:

  • Better evaluate abnormal findings on other imaging
  • Measure cancer tumors after diagnosis
  • Check for other tumors in the body

Additionally, an MRI can show how well cancer treatment – surgery, chemotherapy, or radiation therapy – is working by monitoring the size of the tumor to see if it is shrinking.

Bone scan

A bone scan can rule out whether soft tissue sarcoma has spread to your bones. Also called skeletal scintigraphy, the test uses a small amount of radioactive material to highlight any abnormal tissue, which may indicate cancer.

Bone mineral density test

Your doctor may recommend a bone mineral density test before treatment. Cancer treatment can put you at a higher risk for developing osteoporosis, a condition that causes bone loss and fragile, brittle bones. Measuring your bone mineral density before treatment gives us a baseline, so we can compare later test results with initial bone loss.

Stanford Health Library

For confidential help with your health care questions, contact the Stanford Health Library. Professional medical librarians and trained volunteers can help you access journals, books, e-books, databases, and videos to learn more about medical conditions, treatment options, and related issues.

  • 875 Blake Wilbur, Palo Alto: First floor near the cafe, 650-736-1960
  • South Bay Cancer Center: Third floor lobby, 408-353-0197

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Current as of: 1/2020