CT scan:

These scans are the most common scan performed in cancer patients. They involve lying on a table and entering a tube shaped machine. They can be performed quickly, and provide detailed anatomic information. CT dye allows a more detailed scan, but cannot be used in patients with kidney dysfunction and can cause allergic type reactions. CT scans involve radiation exposure, which is a concern in patients felt to be cured of their cancer who are undergoing frequent surveillance scans. Insurances are generally more liberal about covering CT scans, as opposed to PET scans.

MRI:

These scans involve lying on a table and entering a tube shaped machine. They take longer to perform than CT scans, and can be noisy and confining. The images are generating using a strong magnet, but no radiation. Patients with pacemakers and patients with magnetic metal fragments in their body cannot undergo MRIs. MRIs are the preferred imaging studies when imaging the brain and spinal cord.

PET/CT Scan:

This is a scan that involves the intravenous administration of radioactive glucose called fluorodeoxyglucose (fdg). Once administered, the patient lies on a table and a special camera takes a picture of the body. Areas that take up the radioactive glucose will show up as “hot spots.” The degree of brightness of these “hot spots” is measured in units called SUV. Areas of uptake and high SUV are concerning for cancerous involvement because cancer cells take up more radioactive glucose than surrounding tissues. The PET scan is often done in conjunction with a non IV contrast CT scan. The CT scan and PET scan images are “fused” together using a computer and an image is generated that comprises both the patient’s anatomy from the CT scan and the “hot spots” from the PET scan. Some insurances limit the number of PET scans that can be performed or will only cover these in select indications.

Bone Scan:

This is a scan that involves the intravenous administration of a radionuclide (technetium 99) that is taken up by cells in the bones. Once administered, the patients lies on a table and a special camera takes a picture of the entire skeleton. Areas that take up the radionuclide will show up as “hot spots” in the skeleton. These areas are concerning for areas of cancerous involvement. This scan is different from a bone density scan, which only measures the density of the bones and screens for osteoporosis.