HF-ResDiff: High-Frequency-Guided Residual Diffusion for Multi-dose PET Reconstruction

Zixin Tang, Caiwen Jiang, Zhiming Cui, Dinggang Shen

Abstract: Positron Emission Tomography (PET), an advanced nuclear imaging technology capable of visualizing human biological processes, plays an irreplaceable role in diagnosing various diseases. Nonetheless, PET imaging necessitates the administration of radionuclides into the human body, inevitably leading to radiation exposure. To mitigate the risk, many studies seek to reconstruct high-quality standard-dose PET from low-dose PET to reduce the required dosage of radionuclides. However, these efforts perform poorly in capturing high-frequency details in images. Meanwhile, they are limited to single-dose PET reconstruction, overlooking a clinical fact: due to inherent individual variations among patients, the actual dose level of PET images obtained can exhibit considerable discrepancies. In this paper, we propose a multi-dose PET reconstruction framework that aligns closely with clinical requirements and effectively preserves high-frequency information. Specifically, we design a High-Frequency-guided Residual Diffusion Model (HF-ResDiff) that enhances traditional diffusion models by 1) employing a simple CNN to predict low-frequency content, allowing the diffusion model to focus more on high-frequency counterparts while significantly promoting the training efficiency, 2) incorporating a Frequency Domain Information Separator and a High-frequency-guided Cross-attention to further assist the diffusion model in accurately recovering high-frequency details, and 3) embedding a Dose Control module to enable the diffusion model to accommodate PET reconstruction at different dose levels. Through extensive experiments, our HF-ResDiff outperforms the state-of-the-art methods in PET reconstruction across multiple doses.