While anatomical detail is limited in these studies, nuclear medicine is useful in displaying physiological function. The heart, lungs, thyroid, liver, gallbladder, and bones are commonly evaluated for particular conditions using these techniques. The most commonly used tracers are technetium-99m, iodine-123, iodine-131, gallium-67, and thallium-201. Nuclear medicine imaging involves the administration into the patient of radiopharmaceuticals consisting of substances with affinity for certain body tissues labeled with radioactive tracer. Only generic principles are described, further details are beyond the scope of this chapter and available in their dedicated sections.Īlmir BadnjevićLejla Gurbeta Pokvić, in Clinical Engineering Handbook (Second Edition), 2020 Nuclear medicine This section provides an introduction to basics of the image formation and discuss some general topics that can be applied to both conventional nuclear medicine and positron emission tomography. All three aspects will have a direct impact on the diagnostic accuracy of an imaging modality. It is important to realize that image quality is tightly bound with three factors: (1) the underlying radiation physical detection-e.g., bremsstrahlung radiation, positron range, energy peak, (2) the available mathematical models that approximate the representation of the real object, and (3) the interface between human perception-e.g., the framework in which the graphical data is presented to the image reader. Nuclear medicine scanners provide two-dimensional (2D) projection images of the three-dimensional (3D) objects and tomographic imaging, using specific algorithms able to reconstruct a 3D representation of the objects. Photons emitted by the radiopharmaceuticals are detected by a specific hardware-radiation detectors-and transformed into digital data able to be processed for the purpose of creating images. Nuclear medicine imaging is able to create pictorial representations of organs and physiological processes inside the human or animal body, using surrogate markers labeled with radioactive substances (radiopharmaceuticals), that target specific physiological functions. Pedro Fragoso Costa, in Reference Module in Biomedical Sciences, 2022 Introduction The aim of this chapter is to review the principles of γ camera (both planar and SPECT), with a special emphasis on photomultipliers and analyze all the factors that affect image quality.

In particular new photomultipliers and collimators have improved imaging of small organs and made animal imaging feasible, while other applications, such as imaging of intratumoral heterogeneity are being investigated. Since the first development of the γ camera, continuous advancements in Nuclear Medicine instrumentation have been noted resulting in improvement of spatial resolution and image quality. The name γ camera is coming from the γ rays, which are used to create the images. The first γ camera was developed by an American physicist Hal Anger in the late 1950s and therefore is called Anger or scintillation camera and it is the workhorse in Nuclear Medicine departments. In the beginning, the amount of activity was only calculated, but soon it became clear that spatial distribution of the activity was essential. This is succeeded by external detectors who can detect the emitted photons from the patient's body. In other words, Nuclear Medicine imaging creates a pictorial representation of metabolic processes. The main principle of Nuclear Medicine imaging is to administer a small amount of radioactivity and then detect and image its distribution in the patient's body. Nuclear Medicine imaging both planar and tomographic (single-photon emission computed tomography-SPECT and positron emission tomography-PET), provides metabolic information on the function of organs and tissues. Ioannis Iakovou, in Reference Module in Biomedical Sciences, 2022 Abstract

Affinity radiology