Effect of scan duration on lesion detectability in PET oncology imaging

We have simulated 2D PET acquisitions of an anthropomorphic phantom with numerous spherical target lesions. The diameters of the lesions were varied from 1.0 to 3.0 cm, and the contrast ratios of the lesions were varied from 1.5 to 4.0. Noise-free scans were simulated with an analytical simulator. Poisson noise was added to simulate scan durations ranging from 1 to 10 minutes, using noise equivalent count rates previously measured in 2D whole-body acquisitions of an anthropomorphic phantom. The average detectability of each target lesion under each condition was calculated using a nonprewhitening matched filter. Our results demonstrate the variation of the minimum scan duration required to detect a target of a given size and contrast ratio, for any fixed threshold of detectability.