Final answer:
In Computed Radiography (CR), sampling frequency is often referred to as pixels per millimeter (pixels/mm) or pixel density. This measurement is crucial in creating detailed diagnostic images in medical imaging technologies like MRI and CT scans. Accurate sampling rates and pixel densities are fundamental for clear image resolution, which is integral to medical diagnostics and treatments.
Step-by-step explanation:
The sampling frequency in Computed Radiography (CR) can indeed be expressed as pixels per millimeter (pixels/mm) or pixel density. These terms are essential in the field of medical imaging, particularly when discussing techniques like x-ray computed tomography (CT) scans and magnetic resonance imaging (MRI). With MRI, radio waves are broadcast and absorbed by the body, with their reemission creating images based on the resonance that correlates with the density of nuclei, usually protons, within the body's tissues. Modern medical imaging follows principles of nuclear activity to produce detailed three-dimensional images, which rely heavily on accurate sampling rates and pixel densities to ensure clear and precise diagnostic visuals.
In the context of radiation measurement and therapy, various units of measurement are used. These include becquerels or curies for radioactive decay, grays or rads for absorbed doses, and sieverts for dosimetry measures of tissue damage. For example, Cobalt-60, which has a half-life of 5.26 years, is frequently used in cancer treatment due to its ability to be focused on precise locations, emitting gamma rays for targeted therapy.
Another imaging modality, single-photon-emission computed tomography (SPECT), utilizes radiopharmaceuticals and stationary or rotating detectors to produce images, although it has lower spatial resolution compared to MRI. However, the contrast in SPECT is quite good, making it a valuable tool in certain diagnostic procedures.