What effect occurs due to interactions close to the edge of a detector, potentially leading to variations in image clarity?

The phenomenon of detector parallax occurs when gamma rays emitted from a radioactive source are detected by a positron emission tomography (PET) scanner. Parallax is particularly pertinent when the gamma rays interact with the edges of the detector crystals. If the interaction happens near the detector's edge, it can lead to inaccuracies in determining the exact point of origin for the photons, causing an incorrect positioning of the detected events. This misalignment can obscure the clarity of the resultant images, leading to variations in image quality.

Detector parallax is critical to understand in the context of PET imaging because it can compromise the spatial resolution. When events are inaccurately localized due to parallax, it can affect not just the clarity of images, but also the performance of quantification tasks that PET scans often undertake. Enhanced understanding of this effect allows for better system design and calibration in PET technology, thereby improving image quality and accuracy in diagnostic applications.