A variety of nuclear medicine imaging techniques provide effective methods for the detection and assessment of both clinically apparent and occult infectious and inflammatory conditions. Rather than representing organ-specific techniques, these procedures use radiopharmaceuticals that localize preferentially in inflamed or infected tissue in any location in the body. The available radiopharmaceuticals exhibit varying degrees of nonspecificity and are best used with meticulous clinical correlation. The particular…

18 F-FDG PET Imaging Positron emission tomography (PET) in clinical practice is performed using the hybrid instrumentations of PET/computed tomography (CT) and, to a lesser extent, PET/magnetic resonance imaging (MRI). The most commonly used radiopharmaceutical is fluorine-18 fluorodeoxyglucose ( 18 F-FDG). PET physics and the radiopharmacologic properties of 18 F-FDG have been discussed in Chapter 1 , and PET/CT instrumentation and quality control (QC) have been…

In this chapter, tumor imaging using conventional gamma camera techniques including single-photon emission computed tomography (SPECT) and SPECT/computed tomography (SPECT/CT) as well as less frequently employed or emerging radionuclide tumor therapies are addressed. The more commonly encountered entities of thyroid cancer and bone tumors and metastases are discussed in detail in Chapter 4 and Chapter 8 , respectively. Positron emission tomography (PET) imaging of neoplasms is…

Radionuclide evaluation of the genitourinary system includes quantitative estimates of renal perfusion and function. With the widespread use of magnetic resonance imaging (MRI), computed tomography (CT), angiography, and Doppler ultrasound, the evaluation of renal anatomy by nuclear techniques has diminished, and the role of nuclear renal imaging has become more confined to functional analysis. Indications for radionuclide scanning include assessment of renal blood flow and differential…

The ready availability of cost-effective technetium-labeled bone-seeking radiopharmaceuticals allows the widespread use of bone scanning for both regional and whole-body skeletal assessment in the evaluation of a variety of benign and malignant disease states. The bone scan often provides an earlier diagnosis and demonstrates more lesions than are found by planar radiographic procedures. Although the presence of a lesion on a bone scan is nonspecific, its…

Liver-Spleen Imaging Computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound offer better anatomic display of liver and spleen architecture than does radionuclide liver-spleen imaging, which is rarely performed. However, there remain a few indications for technetium-99m ( 99m Tc) colloid liver-spleen scans, such as the confirmation or evaluation of suspected hepatocellular diseases, hepatomegaly or splenomegaly, and the confirmation of specific space-occupying lesions such as hepatic…

Radionuclide lung imaging most commonly involves the demonstration of pulmonary perfusion using limited capillary blockade, as well as the assessment of ventilation using inspired inert gas, usually xenon, or technetium-99m ( 99m Tc)-labeled aerosols. Although these studies are essentially qualitative, they have an advantage over most quantitative tests of global lung function in distinguishing between diffuse and regional pulmonary disease. Most significantly, the ability to display…

Clinical nuclear medicine studies play a pivotal role in the noninvasive evaluation of cardiac physiology and function. Their widespread use permits the sensitive detection and functional consequences of numerous cardiac abnormalities. About 50% of all nuclear medicine studies done in the United States are for cardiac imaging. In general, radionuclide imaging procedures are designed to assess: Myocardial perfusion and viability Regional and global ventricular function. Notably,…

Thyroid Radioiodine Uptake and Imaging The use of iodine-131 ( 131 I) for measuring thyroid functional parameters and imaging the gland has historically served as a nucleus in the evolution of the field of nuclear medicine, as well as molecular imaging. Although significant changes have taken place in the radionuclide approach to thyroidology, many essential principles remain unchanged. Therefore, a basic understanding of these principles is…

Radionuclide Brain Imaging In specific clinical settings, radionuclide planar, single-photon emission computed tomography (SPECT), or positron emission tomography (PET) brain imaging can provide valuable functional and perfusion information about suspected cerebral abnormalities or cerebrospinal fluid (CSF) dynamics that is not obtained through anatomic imaging. In the normal cerebrum, passage of most substances from the cerebral capillaries into the extravascular space is severely restricted, constituting what is…

Geiger-Mueller Counter Geiger-Mueller (GM) counters are handheld, very sensitive, inexpensive survey instruments used primarily to detect small amounts of radioactive contamination. The detector is usually pancake shaped, although it may be cylindrical ( Fig. 2.1 ). The detector is gas filled and has a high applied voltage from the anode to the cathode. This causes one ionization to result in an “avalanche” of other electrons, allowing…

Basic Isotope Notation The atom may be thought of as a collection of protons, neutrons, and electrons. The protons and neutrons are found in the nucleus, and shells of electrons orbit the nucleus with discrete energy levels. The number of neutrons is usually designated by N. The number of protons is represented by Z (also called the atomic number ). The atomic mass number, or the…