摘要
正电子发射断层扫描(PET)延迟成像在肿瘤异质性分析和治疗评估中具有重要意义,但其临床应用受限于分辨率低、噪声高和定量不准确等问题。计算机断层扫描(CT)能够提供高分辨率的解剖信息,但在肿瘤评估中缺乏功能信息,难以区分良恶性病变和评估代谢活动。虽然动态PET/CT融合能提升图像质量,但多次CT扫描会增加患者累积辐射暴露,不利于长期随访。针对上述问题,提出了一种超分增强PET/CT多模态核矩阵约束算法(SR-PET/CT-KMC)。该算法基于Stable Diffusion对初始扫描PET图像进行超分增强,并将其与初始扫描CT图像的解剖先验信息相结合,建立了多模态PET/CT核矩阵约束的期望最大化(EM)迭代框架。Stable Diffusion用于提升初始扫描PET的分辨率,而多模态PET/CT先验信息则用于抑制噪声和伪影。通过利用初始扫描CT的结构信息,降低了延迟成像中CT扫描的需求,从而减少了患者累积辐射暴露。实验结果表明,SR-PET/CT-KMC与PET-KEM相比,PSNR提高了6.23%,SSIM提高了9.64%,NRMSE降低了33.3%,MSE降低了13.92%;与CT-KEM相比,PSNR提高了4.05%,SSIM提高了1.11%,NRMSE降低了33.3%,MSE降低了8.11%。这些结果表明,SR-PET/CT-KMC在提升延迟扫描PET图像分辨率和定量准确性方面具有优势,为肿瘤代谢追踪提供了一种新的成像范式,提高了延迟PET成像的临床可行性。
Positron emission tomography(PET)delayed imaging is of great significance in tumor heterogeneity analysis and treatment evaluation,but its clinical application is limited by low resolution,high noise and inaccurate quantification.Computed tomography(CT)can provide high-resolution anatomical information,but lacks functional information in tumor assessment,making it difficult to distinguish benign and malignant lesions and evaluate metabolic activity.Although dynamic PET/CT fusion can improve image quality,multiple CT scans increase patient radiation exposure and are not conducive to long-term follow-up.To address the above problems,a super-resolution enhanced PET/CT multimodal kernel matrix constraint algorithm(SR-PET/CT-KMC)is proposed.The algorithm super-enhances the initial scan PET image based on stable diffusion,combines it with the anatomical prior information of the initial scan CT image,and establishes an expectation maximization(EM)iterative framework for multimodal PET/CT kernel matrix constraints.Stable diffusion is used to improve the resolution of the initial scan PET,while the multimodal PET/CT prior information is used to suppress noise and artifacts.By utilizing the structural information of the initial scan CT,the need for CT scans in delayed imaging is reduced,thereby reducing the patient’s cumulative radiation exposure.Experimental results show that compared with PET-KEM,the peak signal-to-noise ratio(PSNR)of SR-PET/CT-KMC is improved by 6.23%,the structural similarity index(SSIM)is improved by 9.64%,the normalized root mean square error(NRMSE)is reduced by 33.3%,and the mean square error(MSE)is reduced by 13.92%.Compared with CT-KEM,the PSNR is improved by 4.05%,the SSIM is improved by 1.11%,the NRMSE is reduced by 33.3%,and the MSE is reduced by 8.11%.These results show that this method has advantages in improving the resolution and quantitative accuracy of delayed scanning PET images,providing a new imaging paradigm for tumor metabolism tracking and improving the clinical feasibility of delayed PET imaging.
作者
宋志超
张建平
张其阳
方玺
谢良
宋少莉
胡战利
SONG Zhichao;ZHANG Jianping;ZHANG Qiyang;FANG Xi;XIE Liang;SONG Shaoli;HU Zhanli(School of Mathematics and Statistics,Wuhan University of Technology,Wuhan 430070,China;Research Center for Medical AI,Shenzhen Institute of Advanced Technology,Chinese Acad emy of Sciences,Shenzhen,Guangdong 518055,China;Department of Nuclear Medicine,Fudan University Shanghai Cancer Center,Shanghai 200032,China)
出处
《计算机科学》
北大核心
2025年第9期119-127,共9页
Computer Science
基金
国家自然科学基金(82372038)。
关键词
延迟成像
超分辨率PET
多模态核矩阵
生物医学
核方法
Delayed imaging
Super-resolution PET
Multi-modal kernel matrix
Biomedical
Kernel method
作者简介
SONG Zhichao,born in 1999,postgraduate.Her main research interests include medical image processing and survival analysis.zcsong.math@whut.edu.cn;通信作者:SONG Shaoli,born in 1972,Ph.D,chief physician,recipient of Shanghai Leading Talents(2023).Her main research interest is basic and cinical research in nuclear medicine of tumors.shaoli-song@163.com。
