Other tests used to stage lung cancer at diagnosis include: 1  Magnetic Resonance Imaging (MRI). A type of imaging scan that uses magnetic fields to create clear images of body parts, including tissues, muscles, nerves and bones. 2  Positron Emission Tomography (PET). A type of imaging scan that is used to tell if lung cancer has spread to other parts of the body. Cells use sugar (glucose) for energy to function and cancer usually uses more than other cells or tissues. A special sugar solution is injected into the body through a vein.