Nuclear medicine is a diagnostic modality that studies the physiology or function of any organ system in the body. Other diagnostic imaging modalities, such as ultrasound, magnetic resonance imaging (MRI), computed tomography (CT), and x-ray, generally visualize anatomic structures.
A pharmaceutical that is used for nuclear scanning is labeled with a radioactive isotope to form a radiopharmaceutical. The radioisotope emits gamma and positron rays. Radioisotopes are reactor produced (iodine 131 [131I]), cyclotron produced (fluorine 18 [18F] for positron emission tomography [PET]), or generator produced (technetium 99m [99mTc]).
To visualize the function of an organ system, a radiopharmaceutical is administered. A time delay (in some cases, up to several hours) may be required for the radiopharmaceutical to reach its target site, and then the organ of interest is imaged using a diagnostic technique called scintigraphy with a gamma camera. Image formation technology involves the detection with very great density of a signal (gamma rays) emanating from the radioactive isotope. There is very little signal in the image that does not come from the radiopharmaceutical. The normal background level of radiation within the human body is minimal, with small amounts of radioactive potassium and some cesium.
Routes of radiopharmaceutical administration vary with the specific study. Most commonly, a radiopharmaceutical is injected through a vein in the arm or hand. Other routes of administration include the oral, intramuscular, inhalation, intrathecal, subcutaneous, and intraperitoneal routes. See Table 9.1 for possible side effects of or adverse reactions to the administration of radiopharmaceuticals.
Nuclear medicine studies are performed by certified nuclear medicine technologists, interpreted by radiologists or nuclear medicine physicians, and performed in a hospital or clinic-based nuclear medicine department. The collaborative approach to care is evidenced by interventions from pharmacists, laboratory personnel, and nurses, among others.
Interventions
Pretest Patient Care and Standard Precautions for Nuclear Medicine Procedures
Explain the purpose, procedure, benefits, and risks of the nuclear medicine procedure.
Assess for allergies to substances such as iodine.
Reassure the patient that the procedure is safe and painless.
Inform the patient that the procedure is performed in the nuclear medicine department. Contact the department to determine the expected time and length of the procedure.
Have the patient appropriately dressed.
Obtain an accurate weight because the radiopharmaceutical dose may be calculated by weight.
If a female patient is premenopausal, determine whether she may be pregnant. Pregnancy is a contraindication to most nuclear imaging to avoid irradiation of the fetus.
Clinical Alert
Nuclear medicine procedures are usually contraindicated in pregnant women. Lactating women may need to discard their breast milk for several days following the procedure.
These precautions should also be followed for the radionuclide laboratory procedures and PET imaging.
Posttest Patient Care and Standard Precautions for Nuclear Medicine Procedures
Use routine disposal procedures for body fluids and excretions unless directed otherwise by the nuclear medicine department. Special considerations for disposal must be followed for therapeutic procedures.
Record any problems that occurred during the procedure, interventions provided, and patient response to those interventions.
Monitor the injection site for signs of bruising, hematoma, infection, discomfort, or irritation.
Assess for side effects of radiopharmaceuticals.
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