Time of flight PET reconstruction using nonuniform update for regional recovery uniformity

Purpose Time of flight (TOF) PET reconstruction is well known to statistically improve the image quality compared to non‐TOF PET. Although TOF PET can improve the overall signal to noise ratio (SNR) of the image compared to non‐TOF PET, the SNR disparity between separate regions in the reconstructed image using TOF data becomes higher than that using non‐TOF data. Using the conventional ordered subset expectation maximization (OS‐EM) method, the...