How is a metastasis of lung cancer detected?

A metastasis is usually found by medical imaging tests, and there are three types used primarily for this purpose. Radiologic testing implies tests which use radiation to create images of parts of the body like chest x-rays or CT (Computed Tomography) scans. The second common imaging technique is nuclear medicine scans, which use intravenous injection of low dose radioisotopes. Special cameras (scanners) are then used to create images of the radiation given off by the isotopes from inside the body, and metastases can be detected in this way. The most common nuclear scan is called a PET scan (Positron Emission Tomography). Finally, magnetic waves emitted by tissues within the human body can be detected and used to create images of the organs which allow a metastasis to be identified. Such tests are called MRI (Magnetic Resonance Imaging) scans.

However, even when a suspicious "spot" is seen on such an x-ray or scan, it usually requires confirmation that it is cancer and that often means performing a biopsy (obtaining a sample of the tissue).