深度学习CT重建(DLR)作为一种提高图像质量和减少辐射暴露的方法越来越受欢迎。由于它们的非线性性质,这些算法导致分辨率和噪声性能是对象相关的。因此,传统的CT体模,缺乏真实的组织形态,已经变得不足以评估临床成像性能。我们建议利用3D打印的PixelPrint幻影,表现出逼真的衰减轮廓,纹理,和结构,作为评估DLR性能的更好工具。在这项研究中,我们评估了一种DLR算法(精确图像(PI),PhilipsHealthcare)使用自定义PixelPrint肺部体模,并在DLR、迭代重建,和滤波反投影(FBP),扫描在宽范围的辐射曝光(CTDIvol:0.5、1、2、4、6、9、12、15、19和20mGy)。我们使用噪声比较了每个结果图像的性能,峰值信噪比(PSNR),结构相似性指数(SSIM),基于特征的相似性指数(FSIM),基于信息理论的统计相似性度量(ISSM)和通用图像质量指数(UIQ)。9mGy的迭代重建与所有指标的12mGy(诊断参考水平)的FBP图像质量相匹配,显示25%的剂量减少能力。同时,DLR匹配剂量在4-9mGy之间的诊断参考水平FBP图像的图像质量,显示25%和67%之间的剂量减少能力。这项研究表明,与FBP和迭代重建相比,DLR可以减少辐射剂量,而不会损害图像质量。此外,在评估新型CT技术时,与传统的体模相比,PixelPrint体模提供了更现实的测试条件。这个,反过来,促进新技术的翻译,如DLR,进入临床实践。
Deep learning CT reconstruction (DLR) has become increasingly popular as a method for improving image quality and reducing radiation exposure. Due to their nonlinear nature, these algorithms result in resolution and noise performance which are object-dependent. Therefore, traditional CT phantoms, which lack realistic tissue morphology, have become inadequate for assessing clinical imaging performance. We propose to utilize 3D-printed PixelPrint phantoms, which exhibit lifelike attenuation profiles, textures, and structures, as a better tool for evaluating DLR performance. In this study, we evaluate a DLR algorithm (Precise Image (PI), Philips Healthcare) using a custom PixelPrint lung phantom and perform head-to-head comparisons between DLR, iterative reconstruction, and filtered back projection (FBP) with scans acquired at a broad range of radiation exposures (CTDIvol: 0.5, 1, 2, 4, 6, 9, 12, 15, 19, and 20 mGy). We compared the performance of each resultant image using noise, peak signal to noise ratio (PSNR), structural similarity index (SSIM), feature-based similarity index (FSIM), information theoretic-based statistic similarity measure (ISSM) and universal image quality index (UIQ). Iterative reconstruction at 9 mGy matches the image quality of FBP at 12 mGy (diagnostic reference level) for all metrics, demonstrating a dose reduction capability of 25%. Meanwhile, DLR matches the image quality of diagnostic reference level FBP images at doses between 4 - 9 mGy, demonstrating dose reduction capabilities between 25% and 67%. This study shows that DLR allows for reduced radiation dose compared to both FBP and iterative reconstruction without compromising image quality. Furthermore, PixelPrint phantoms offer more realistic testing conditions compared to traditional phantoms in the evaluation of novel CT technologies. This, in turn, promotes the translation of new technologies, such as DLR, into clinical practice.