{"title":"A New Adaptive Sliding Window Method for fMRI Dynamic Functional Connectivity Analysis","authors":"Ningfei Jiang, Yuhu Shi","doi":"10.1002/ima.70154","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>The fixed-window sliding time window method is widely used in exploring dynamics functional connectivity of functional magnetic resonance imaging data analysis, but it is difficult to select a suitable window to capture the dynamic changes in brain function. Therefore, a local polynomial regression (LPR) method is proposed to fit the region of interest (ROI) time series in this paper, in which observations are locally modeled by a least-squares polynomial with a kernel of a certain bandwidth that allows for better bias-variance tradeoff. It combines a data-driven variable bandwidth selection mechanism with intersection of confidence intervals (ICI) and a bandwidth optimization algorithm of particle swarm optimization (PSO). Among them, ICI is used to adaptively determine the locally optimal bandwidth that minimizes the mean square error (MSE), and then the bandwidth values at various time points within all ROIs are computed for each subject. Subsequently, the averaged bandwidth values at these time points is regarded as the bandwidth value for that subject at each time point, followed by generating a time-varying bandwidth sequence for each subject, which is used in the PSO-based bandwidth optimization algorithm. Finally, the results of experiments conducted on simulated data showed that the LPR–ICI–PSO method exhibited lower MSE values on time-varying correlation coefficient estimation for different noise scenarios. Furthermore, we applied the proposed method to the autism spectrum disorder (ASD) study, and obtained a classification accuracy of 74.1% from typical controls (TC) through support vector machine (SVM) with the 10-fold cross-validation strategy. These results demonstrated that our proposed method can effectively capture the dynamic changes in brain function, which is valid in clinical diagnosis and helps to reveal the differences in brain functional connectivity patterns.</p>\n </div>","PeriodicalId":14027,"journal":{"name":"International Journal of Imaging Systems and Technology","volume":"35 4","pages":""},"PeriodicalIF":3.0000,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Imaging Systems and Technology","FirstCategoryId":"94","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/ima.70154","RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
The fixed-window sliding time window method is widely used in exploring dynamics functional connectivity of functional magnetic resonance imaging data analysis, but it is difficult to select a suitable window to capture the dynamic changes in brain function. Therefore, a local polynomial regression (LPR) method is proposed to fit the region of interest (ROI) time series in this paper, in which observations are locally modeled by a least-squares polynomial with a kernel of a certain bandwidth that allows for better bias-variance tradeoff. It combines a data-driven variable bandwidth selection mechanism with intersection of confidence intervals (ICI) and a bandwidth optimization algorithm of particle swarm optimization (PSO). Among them, ICI is used to adaptively determine the locally optimal bandwidth that minimizes the mean square error (MSE), and then the bandwidth values at various time points within all ROIs are computed for each subject. Subsequently, the averaged bandwidth values at these time points is regarded as the bandwidth value for that subject at each time point, followed by generating a time-varying bandwidth sequence for each subject, which is used in the PSO-based bandwidth optimization algorithm. Finally, the results of experiments conducted on simulated data showed that the LPR–ICI–PSO method exhibited lower MSE values on time-varying correlation coefficient estimation for different noise scenarios. Furthermore, we applied the proposed method to the autism spectrum disorder (ASD) study, and obtained a classification accuracy of 74.1% from typical controls (TC) through support vector machine (SVM) with the 10-fold cross-validation strategy. These results demonstrated that our proposed method can effectively capture the dynamic changes in brain function, which is valid in clinical diagnosis and helps to reveal the differences in brain functional connectivity patterns.
期刊介绍:
The International Journal of Imaging Systems and Technology (IMA) is a forum for the exchange of ideas and results relevant to imaging systems, including imaging physics and informatics. The journal covers all imaging modalities in humans and animals.
IMA accepts technically sound and scientifically rigorous research in the interdisciplinary field of imaging, including relevant algorithmic research and hardware and software development, and their applications relevant to medical research. The journal provides a platform to publish original research in structural and functional imaging.
The journal is also open to imaging studies of the human body and on animals that describe novel diagnostic imaging and analyses methods. Technical, theoretical, and clinical research in both normal and clinical populations is encouraged. Submissions describing methods, software, databases, replication studies as well as negative results are also considered.
The scope of the journal includes, but is not limited to, the following in the context of biomedical research:
Imaging and neuro-imaging modalities: structural MRI, functional MRI, PET, SPECT, CT, ultrasound, EEG, MEG, NIRS etc.;
Neuromodulation and brain stimulation techniques such as TMS and tDCS;
Software and hardware for imaging, especially related to human and animal health;
Image segmentation in normal and clinical populations;
Pattern analysis and classification using machine learning techniques;
Computational modeling and analysis;
Brain connectivity and connectomics;
Systems-level characterization of brain function;
Neural networks and neurorobotics;
Computer vision, based on human/animal physiology;
Brain-computer interface (BCI) technology;
Big data, databasing and data mining.