Approximately how much blurring effect is caused by non-colinearity on clinical PET scanners?

Non-collinearity in clinical PET scanners refers to the phenomenon where the annihilation photons emitted from a positron-electron collision do not travel directly opposite each other due to slight variations in their emission angles. This results in a blurring effect when the scanner attempts to determine the exact location of the annihilation event.

The blurring caused by non-collinearity is typically quantified in millimeters. Research and calibration data from clinical systems indicate that the non-collinearity effect contributes approximately 2 mm of blurring. Understanding this parameter is important because it impacts image resolution and accuracy in PET imaging, which are crucial for diagnosis and treatment planning.

The knowledge of this blurring magnitude also helps technicians and medical physics experts in interpreting PET images and considering how non-collinearity impacts the overall image quality.