A nuclear medicine specialist employs the properties of radioactive atoms and molecules in the diagnosis and treatment of disease, and in research. Radiation detection and imaging instrument systems are used to detect disease as it changes the function and metabolism of normal cells, tissues, and organs. A wide variety of diseases can be found in this way, usually before the structure of the organ involved by the disease can be seen to be abnormal by any other techniques. Early detection of coronary artery disease (including acute heart attack); early cancer detection and evaluation of the effect of tumor treatment; diagnosis of infection and inflammation anywhere in the body; and early detection of blood clot in the lungs are all possible with these techniques. Unique forms of radioactive molecules can attack and kill cancer cells (e.g., lymphoma, thyroid cancer) or can relieve the severe pain of cancer that has spread to bone. The nuclear medicine specialist has special knowledge in the biologic effects of radiation exposure, the fundamentals of the physical sciences and the principles and operation of radiation detection and imaging instrumentation systems.