Final answer:
Partial or fractional averaging is a technique used in single-photon-emission computed tomography (SPECT) to improve image quality by reducing noise and improving the signal-to-noise ratio (SNR).
Step-by-step explanation:
Patial or fractional averaging is a technique used in single-photon-emission computed tomography (SPECT) to improve image quality. It involves acquiring multiple images of a particular area and then averaging them together to reduce noise and improve the signal-to-noise ratio (SNR).
This technique is particularly useful in situations where the SNR is low, such as in low-dose or low-count imaging. By averaging multiple images, the noise is reduced, resulting in a clearer and more accurate image.
For example, in SPECT imaging, a radioactive tracer is injected into the patient's body and emits gamma rays. These gamma rays are detected by solid-state radiation detectors, which convert the gamma rays into electrical signals. By acquiring multiple images and averaging them, the noise from random fluctuations in the detected signals can be reduced, resulting in a higher SNR and better image quality.