What is the typical range for coincidence timing windows in PET imaging?

In PET imaging, the coincidence timing window refers to the time period during which two detected gamma photons, resulting from the annihilation of a positron and an electron, are considered to be created from the same event. This timing window is crucial because it helps in accurately identifying true coincidences while minimizing the impact of random coincidences, which can degrade image quality.

The typical range for coincidence timing windows in PET imaging is generally accepted to be between 4 to 12 nanoseconds. This range ensures a good balance between maintaining a sufficient number of detected events to produce high-quality images and excluding random coincidences that may result from unrelated events occurring close in time. The selection of this range is based on the speed and timing resolution of the detection system, allowing for effective discrimination between true and false events.

Options providing ranges outside of 4-12 nanoseconds, such as 1-5 ns or broader ranges like 10-20 ns and 15-30 ns, are not considered typical in contemporary clinical PET systems. Using too short of a window may lead to the omission of valid coincident pairs, while excessively long windows could accumulate too many random events, ultimately compromising image clarity. Therefore, the range of 4-12 nanoseconds is recognized