What is PET/CT?

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PET/CT Imaging at the Swedish Cancer Institute

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Positron Emission Tomography (PET) captures images of miniscule changes in the body’s metabolism caused by the growth of abnormal cells. A PET scan can detect abnormalities in cellular activity generally before there is any anatomical change.

Computed Tomography (CT) uses x-rays and a computer to make detailed images of sections of the body’s internal structure. A CT scan shows your body’s organs, bones and tissues in great detail (size and location of the tumor, mass, etc.).

Overall, a PET scan provides metabolic detail (cellular activity of the tumor, mass, etc.). CT scans yield sharp anatomic images but don’t show physiologic activity. Fusion of PET and CT images provide the oncology team with the best understanding of how to best treat you and whether or not your current treatment is working.

The fusion of PET/CT

One of the most important advances in imaging has been the fusion of PET and CT. Using a PET/CT scanner, physicians can view images in three different planes – axial, coronal, and sagittal, with high-quality resolution that they can use to see where disease tissue ends and healthy tissue begins. The scanner also detects the metabolic activity of cells, which helps physicians better understand changes at the cellular level that could be early indications of cancer. 

PET/CT exams have proven invaluable in helping oncologists make more accurate diagnosis and staging assessments, choose the most appropriate therapies, and determine whether or not a therapy is effective against a cancer. 

Physicians are using PET/CT exams to help diagnose and assess a variety of cancers, including but not limited to breast, cervical, colorectal, esophageal, gastrointestinal, head and neck, lung, lymphoma, melanoma, multiple myeloma, soft tissue sarcoma and thyroid. PET/CT Imaging at the Swedish Cancer Institute was one of the first in the nation to offer computer-aided advanced lung nodule detection and analysis, a state-of-the-art set of imaging and analysis tools that can benefit patients with lung cancer or patients at risk for lung cancer. Additionally, PET/CT exams help radiation oncologists during treatment planning phase. PET/CT exams help radiation oncologists target the exact location of the tumor for radiation treatment, determine appropriate dosage levels, and minimize damage to healthy tissue in the process. 

PET/CT Imaging at the Swedish Cancer Institute was developed through a partnership between Swedish Medical Center/Swedish Cancer Institute, Seattle Nuclear Medicine and Tumor Institute Radiation Oncology Group.