چكيده لاتين
In recent decades, PET-CT imaging has played a vital role in the diagnosis and treatment of diseases as one of the most advanced molecular imaging techniques. However, the quality of PET-CT images at low radiation doses is limited due to noise and quality degradation, which particularly poses challenges in the accurate diagnosis of diseases and medical treatments, especially in sensitive groups such as children. Improving the quality of low-dose PET-CT images using deep learning techniques, particularly convolutional neural networks and generative adversarial models, has been proposed as an innovative solution. In previous studies, deep learning models such as 3D U-Net have been used to improve the quality of low-dose PET-CT images. These methods have shown better performance compared to single-input models by reducing noise and improving metrics such as PSNR and RMSE. Specifically, multi-channel models have been able to reduce RMSE by 22.22% and significantly increase PSNR, bringing the image quality to the level of standard-dose images. However, challenges such as reliance on diverse data, higher computational complexity compared to single-input models, and limited generalizability to other devices and clinical conditions remain issues.This study aims to improve the quality of low-dose PET-CT images by using the deep learning model ResUNet 3D. The data used in this study consists of 219 images from the head and neck region at three different dose levels (2%, 5%, and 10%), with preprocessing steps such as normalization, resizing, and noise removal applied. The proposed model was designed by combining the ResNet and U-Net architectures and evaluated based on the metrics RMSE, PSNR, and SSIM. The results showed that the best performance was observed at epoch 35, where RMSE improved to 0.0069 ± 0.0025 for the 10% dose, noise was reduced, and the structural details of the images were preserved. Furthermore, PSNR increased from 22 to 43, indicating a significant improvement in the quality of the reconstructed images. These results demonstrate the high potential of the proposed model in reducing noise, improving reconstruction accuracy, and enhancing the quality of low-dose medical images.The findings of this study indicate that the ResUNet 3D model outperformed similar models such as HighResNet in terms of PSNR, SSIM, and RMSE. Specifically, the proposed model was able to reduce noise and increase image reconstruction accuracy. The reasons for these improvements include more precise processing of spatial and contextual features of low-dose images and the use of residual blocks and larger training datasets. The advantages of this model include noise reduction, improved reconstruction accuracy, and its potential application in reducing radiation dose without compromising image quality in clinical settings. Despite limitations such as the need for large training datasets and powerful hardware resources, the ResUNet 3D model holds significant potential in optimizing the quality of medical images and reducing radiation dose.