GammaKameras

GammaKameras are imaging devices used in nuclear medicine to visualize the distribution of radiopharmaceuticals within the body by detecting gamma rays emitted by radioactive tracers. They provide functional information about organs and are used for diagnostic imaging and treatment planning; many systems also support tomographic imaging through rotating detectors.

Core components include a collimator, a scintillation crystal, and an array of sensors paired with readout electronics. The collimator governs the direction of incoming photons, the crystal converts them to light, and the sensors translate the light into electrical signals. The Anger camera concept uses the light distribution across the sensor array to estimate the gamma interaction position.

Common radiotracers include technetium-99m for many studies, iodine-123, thallium-201, and gallium-67. Tc-99m emits photons near 140 keV, which aligns with the energy windows used by standard gamma cameras. Imaging methods include planar acquisition and single-photon emission computed tomography (SPECT); CT can be added for anatomical reference in hybrid systems.

Advances include solid-state detectors such as cadmium zinc telluride (CZT), which offer better energy resolution and compact designs, and newer reconstruction techniques. Some systems employ multidetector arrangements and specialized collimators (e.g., pinhole or multi-pinhole) to optimize resolution for specific applications. Hybrid SPECT/CT and SPECT/CT-based workflows are common in contemporary practice.

Applications span myocardial perfusion imaging, bone and renal scans, thyroid imaging, brain studies in selected cases, and sentinel lymph node mapping. GammaKameras remain a foundational technology in nuclear medicine, balancing diagnostic value with radiation exposure and workflow considerations.