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.
Overview. A positron emission tomography scan is an imaging test that uses nuclear medicine to view the body on a cellular level. The PET scan measures body functions, such as blood flow, metabolism and oxygen use, and may be used to detect disease, like cancer, and heart and brain problems. There are different types of PET scans. You may need to follow a low-carbohydrate diet 12 hours prior to a PET scan.