高技术通讯2026，Vol.36Issue(1)：15-28,14.DOI:10.3772/j.issn.1002-0470.2026.01.002
基于Q空间轨迹成像具有半正定约束的扩散偏度成像
Diffusion skewness imaging based on Q-space trajectory imaging with semidefinite constraints
摘要
Abstract
Q-space trajectory imaging(QTI)aims to improve the differentiation of tissue structures in microenvironments by exploring microstructures through diffusion tensor distribution(DTD)models.In this work,low-order term fit-ting will discard sustantial useful information when considering irregularity of the measured signals.To enrich struc-tural details and improve the accuracy of the indicators,skewness tensors of higher orders are introduced.For the extended model,to ensure the rationality of the results,this article proposes three constraints that the mean diffu-sion tensor,the covariance tensor and the skewness tensor should satisfy.It also demonstrate their necessity.To fa-cilitate the constraints to be added to the computation,semidefinite programming(SDP)is used to solve the prob-lem.In addition,this article also introduces a filtering function to characterize the microstructure.Finally,Gaussi-an noise is added to the preprocessed dataset to investigate the effect of noise on our method.By discussing the ne-cessity of the constraints,it can be found that if we do not enforce strict nonnegativity on the model,the results ob-tained from the final computation may show large errors,which can affect our analysis of the organizational struc-ture.Accordingly,this article tested the effect of noise,and the experimental results show that the appearance of noise will bring a certain error to the results,which is not ignorable.关键词
扩散磁共振成像/Q空间轨迹成像/偏度张量/半正定规划/微观分数各向异性Key words
diffusion magnetic resonance imaging(MRI)/Q-space trajectory imaging/skewness tensor/semidefinite programming/microscopic fractional anisotropy引用本文复制引用
陈赞,滕召翼,冯远静..基于Q空间轨迹成像具有半正定约束的扩散偏度成像[J].高技术通讯,2026,36(1):15-28,14.基金项目
国家自然科学基金(62002327,U22A2040,U23A20334)和浙江省自然科学基金(LQ21F020017)资助项目. （62002327,U22A2040,U23A20334）
