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  • PET Uses

  • PET scan of lymphoma

    15 mCi  68 min. p.i.: 3 min em  43 sec tx/step
    Images courtesy of University of Pennsylvania


    PET is particularly effective in identifying whether cancer is present or not, if it has spread, if it is responding to treatment, and if a person is cancer free after treatment. Cancers for which PET is considered particularly effective include lung, head and neck, colorectal, esophageal, lymphoma, melanoma and breast, as well as a variety of other tumors for which the effectiveness of PET is currently under investigation.

    • Early Detection
      Because PET images biochemical activity, it can accurately characterize a tumor as benign or malignant. This can eliminate the need for a surgical biopsy in some cases.
    • Staging of Cancer
      PET can accurately determine the full extent of a disease, especially in lymphoma, malignant melanoma, breast, lung and colon cancers. This sensitivity allows the physician to choose among treatment options more effectively.
    • Checking for Recurrences
      PET is currently considered to be the most accurate diagnostic procedure when it comes to differentiating tumor regrowth from common radiation or surgical side-effects. This approach allows the physician to develop a more accurate treatment plan for the patient.
    • Assessing the Effectiveness of Chemotherapy
      Tumor metabolism can be compared on PET scans taken before and after a chemotherapy cycle. Because of this PET can provide important information about the effectiveness of a chemotherapy treatment plan.


    PET scan of focal epilepsy

    2 mm slices
    Images courtesy of University of Pennsylvania

    With CT or MRI

    Because PET measures metabolism it can be superior to other procedures, particularly in differentiating tumors from benign lesions, and in differentiating malignant tumors from non-malignant masses such as scar tissue, which may be formed from treatments like radiation therapy. In specific instances, PET may be used in conjunction with an MRI or CT scan through "fusion" to give a full three-dimensional view of an organ and the location of a tumor within that organ.

    Neurological Disease

    A PET scan's ability to measure metabolism has significant implications for diagnosing epilepsy, because it can vividly illustrate areas where brain activity differs from the norm.

    Cardiovascular Disease

    PET scans can pinpoint areas of decreased blood flow caused by blockages, and differentiate muscle damage from living muscle. This information is particularly important in patients who have had a previous heart attack and who are being considered for a cardiac procedure.


    For more information about PET at Rhode Island Hospital or to schedule a physician-referred appointment, please call 401-444-7383.