Noise components on positron emission tomography images.

Noise components on PET images were studied. The results showed that the square of synthetic noise Delta(2) and the square of signal-to-noise ratio (N/Delta)(2) varied with the signal intensity N and the relationships were respectively expressed with: Delta(2)=0.0395N(2)+0.1427N+0.0025 (R(2)=0.9358) and (N/Delta)(2)=-1.13932N(2)+7.0185N-0.0746 (R(2)=0.9377). The synthetic noise on PET image may be categorized into three components. The first one varies directly as signal intensity, which depend on random coincidence; the second one varies directly as the square root of signal intensity, which depend on Poisson fluctuation; and the third one is independent of signal intensity.