When a particular sign or symptom may be related to cancer, the first step is an accurate diagnosis. Although we use a number of tests and procedures, diagnostic imaging is vital in the detection and diagnosis of cancer.
Diagnostic imaging uses technologies to produce detailed pictures of what's inside the body. In many cases one or a combination of the medical imaging procedures briefly described below can show the presence, size, shape and location of tumors or abnormalities in your body. In some cases, these tests can help determine if the problem is cancerous (malignant) or noncancerous (benign).
While these pictures are a valuable tool in most cases, not all cancers can be seen through diagnostic imaging. A tumor may be too small or in a location that’s difficult to see. In these instances, other tests may prove more useful and may be part of your diagnosis.
A final diagnosis of cancer usually requires a biopsy — an examination of cells or living tissue from an area suspected to be cancerous. Biopsies are the most definitive way to test for the presence of a malignant tumor and to determine what kind of cancer exists. Diagnostic imaging and biopsy together are essential for developing an effective treatment plan.
Below you will see details on diagnostic procedures available at Riverside.
Computerized tomography, or CT scan
Sometimes called a CAT scan, a CT scan is a special type of cross sectional X-ray generated by a computer. The result is a more detailed image than a conventional X-ray. When used in cancer diagnosis, CT scans are typically used to pinpoint a tumor deep in the brain, lungs, liver, pancreas, adrenal glands and bones.
A mammogram is a specific type of X-ray imaging that uses low-dose radiation to examine the breasts. Mammograms identify breast cancer or abnormalities in individuals with or without symptoms. A mammogram plays an important role in the early detection of breast cancer because it can show changes in the breast up to two years before you or your doctor can feel them. After the initial screening mammogram, there are additional types of mammograms that a radiologist can use for more detailed views, including digital mammography.
Magnetic resonance imaging, or MRI
Like CT scans, MRI provides a detailed view of the body, but relies on a different technology. MRI uses a strong magnet and radiofrequency waves to produce a computer-generated image of internal organs and structures. In some cases, MRI can be more sensitive than CT and is often used to detect cancer of the brain, spinal cord, head and neck, liver and soft tissues.
Nuclear medicine tests are used in cancer diagnosis, often in the form of bone, liver and thyroid scans. A small and safe amount of radioactive material is injected into the blood stream where it becomes absorbed in all tissues and bones. Cancerous cells absorb this material at a faster rate than normal, healthy tissue, which helps locate areas of disease.
Positron emission tomography, or PET, and PET/CT
Unlike CT and MRI scans that provide images of structures in the body, PET scans show chemical changes related to metabolism or body activity. Before a PET scan, a patient will receive an injection of a small amount of a radioactive drug. All tissues absorb some of this drug – called an isotope – but cancerous cells are hypermetabolic, meaning they absorb greater amounts, which enables them to be seen on the scan. PET is used to locate cancerous tumors and to see if the disease has spread to other parts of the body.
Research indicates that combining the PET images into the images provided through CT scanning provides the best of both technologies. This procedure is particularly effective for diagnosing the original cancer site as well as any spread to nearby lymph nodes or more distant sites in the body.
Also called a sonogram, ultrasound works by bouncing high frequency sound waves off tissues in your body to form images. This technology is used to help diagnose cancers in the breast, liver, kidneys, uterus and ovaries.