High Quality Image Reconstruction for Short Frame in Dynamic PET

Low count PET studies usually suffer from high image noise and quantitative bias in reconstructed image. This is particularly significant for short frames (temporal-ROI, or T-ROI) in dynamic PET studies, which in some cases may be as short as 30 seconds or less. In this paper, we proposed a method to improve the quality of the reconstructed short frame by utilizing information from a longer acquisition time that contains the short frame. The data of the longer acquisition excluding the short frame is first sorted to perform a reconstruction. The reconstructed image is then forward projected to obtain its contribution in the data space. A second reconstruction is then executed with data from the entire long acquisition (including the short frame) and the previous contribution in the data space to estimate the activity for the short frame. Results show that the image quality and CRC-noise performance are both improved with our proposed method than the standard reconstruction with counts from the target frame only, as well as the complementary reconstruction method published earlier.