Ligaments attach your breasts to the pectoral muscle on your chest. When you wear a bra, your supported breast does not allow the pectoral muscle to be exercised as much as it could be. When you do not wear a bra, as you move your arms, reach, and lift, your pectoral muscle is strengthened.
Positron emission tomography. Positron emission tomography (PET) is a nuclear medicine functional imaging technique that is used to observe metabolic processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (tracer), which is introduced into the body on a biologically active molecule.
What Is a Heart PET Scan? A positron emission tomography (PET) scan of the heart is an imaging test that uses specialized dye to allow your doctor to view problems with your heart. The dye contains radioactive tracers, which concentrate on areas of the heart that may be injured or diseased.