Nuclear medicine is a medical specialty that involves the use of radioactive substances as part of the diagnostic process and treatment. The procedures are based on radiopharmaceuticals created by combining chemical or pharmaceutical compounds with radionuclide. When administered to the patient, the radiopharmaceuticals localize to specific organs and are used to image how far has a disease process spread inside the body.
Nuclear medicine can be compared to a radiology done inside out, because it records the radiation emitting from inside the body that is not generated by external sources. In some cases, nuclear medicine can identity a disease at an earlier stage than any other test could and in a non-invasive manner. The imaging techniques combine the use of radioactive substances with detectors and computers.
Techniques such as Single photon emission computed tomography (SPECT), Bone scanning, Positron emission tomography (PET) and Cardiovascular imaging use different properties of the radioactive substances to generate detailed images and different tests or combination of tests as part of the diagnostic process. These methods are useful for detecting aneurysms, irregular or inadequate blood flow to various tissues, tumors, inadequate functioning of organs, and blood cell disorders.
In nuclear medicine imaging, the patient must take the radiopharmaceuticals internally, orally or intravenously. The imagines are captured and formed by the external detectors, such as gamma cameras, from the radiation emitted by the substance. The 2D Scintigraphy technique creates two-dimensional images by using internal radionuclides. 3D tomographic technique such as 3D SPECT used gamma cameras to capture data while Positron emission tomography (PET) is a hybrid technique also called image fusion that can image functional processes with the help of coincidence detection.
PET is a powerful diagnostic tool because it provides information about the function and anatomy of the body that would otherwise require invasive procedures and even surgery. With the help of this nuclear medicine imaging method, most cancers and stages can be detected. Furthermore, it gives doctors early information about many neurological disorders and heart disease. PET is the most accurate and non-invasive way to identify small tumors and to tell whether it is malignant of benign.
Due to the fact that the risks of exposure to low-level radiation are not fully understood, an universal cautious approach called ALARP (As Low As Reasonably Practicable) has been adopted. Even if the benefit justifies the procedure, the radiation exposure involved in nuclear medicine imaging is kept as low as possible. A larger amount of radiation creates better quality images, although they should never be better than required to confirm the diagnosis.