Imaging neuroscience (Cambridge, Mass.)最新文献

{"title":"Head-to-head comparison of diffusion imaging markers for cognitive decline and risk of dementia: The population-based Rotterdam Study.","authors":"Mathijs T Rosbergen, Frank J Wolters, M Arfan Ikram, Meike W Vernooij","doi":"10.1162/IMAG.a.1382","DOIUrl":"10.1162/IMAG.a.1382","url":null,"abstract":"<p><p>Diffusion tensor imaging (DTI) is a promising tool for early detection of white matter deterioration, but the optimal DTI marker for assessing risk of cognitive decline and dementia is undetermined. The aim of this study was to compare the predictive value of multiple diffusion measures for cognitive decline and dementia risk in a population-based study. We measured peak-width skeletonized mean diffusivity (PSMD), normal-appearing white matter mean diffusivity (MD), and fractional anisotropy (FA) in participants aged 45 years and older who underwent 1.5T MRI between 2006-2015 as part of the ongoing prospective population-based Rotterdam Study. In a head-to-head comparison between DTI markers, we determined risk of cognitive decline and dementia during follow-up, using linear regression and Cox proportional hazard models, respectively, that also include age, sex, education, and presence of lacunes or microbleeds. Of 5230 participants (mean age: 65.0 years +/-10.9 [standard deviation], 55.8% women), 286 developed dementia during a median follow-up of 9.8 years. For dementia risk, PSMD and global MD were superior regarding model fit, with the highest hazard ratio for global MD (HR: 1.74 [95%CI: 1.53-1.98])<i>.</i> Similarly, PSMD and MD had the highest discriminatory value (C-statistic, for PSMD: 0.886, and for MD: 0.882), albeit differences with other measures were small. Of all participants, 4433 (84.3%) had complete data on all cognitive tests at baseline, of whom 2800 (63.2%) completed their follow-up visit after on average 5.6 years. For global cognition both at time of MRI and at follow-up, PSMD was superior in terms of model fit and showed the highest regression coefficients, followed by tract-specific measures of MD and FA. In conclusion, when directly comparing structural connectivity measures, PSMD is superior to MD and FA for prediction of cognition and cognitive decline, while PSMD and MD perform best with respect to dementia risk.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13644046/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149139746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Philadelphia Theta Burst Project: A novel fMRI-guided electric field modeling dataset with reliability metrics.","authors":"David F Gregory, Ivy Sun, Marta Teferi, Hannah Gura, Milan Patel, Abigail Casalvera, Sneha Chandrashekar, Kevin G Lynch, Douglas H Schultz, Ashish Jeyapratap, Quinn Tate, Walid Makhoul, Zhi-De Deng, Desmond J Oathes, Yvette I Sheline, Nicholas L Balderston","doi":"10.1162/IMAG.a.1314","DOIUrl":"10.1162/IMAG.a.1314","url":null,"abstract":"<p><p>Recent neuromodulation studies suggest that theta burst stimulation (TBS) applied to the dorsolateral prefrontal cortex (dlPFC) can influence neural circuits involved in cognitive control and emotion-related processing, with relevance for psychiatric disorders. However, large-scale datasets characterizing variability, reliability, and multimodal neural responses to TBS remain limited. To address this gap, we established the Philadelphia Theta Burst Project, a dataset of 100 healthy participants who completed 4 fMRI sessions following cumulatively increasing doses of intermittent or continuous TBS, with participants randomized to one protocol or the other. Each session includes multiband, multi-echo resting-state (16 minutes) and task-based fMRI (16 minutes) during a Sternberg working memory paradigm. TMS targeting was guided by task-evoked activation in the left dlPFC. Structural T1-weighted, T2-weighted, and diffusion-weighted imaging were also acquired. Here, we describe the dataset design, acquisition protocol, and data characteristics, and report initial measures of data quality and reliability. The completed dataset can be accessed at https://openneuro.org/datasets/ds008893, providing an open resource for future investigations of TBS mechanisms and individualized neuromodulation strategies.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13641012/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149119564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial distribution of spinal cord fMRI activity with electrocutaneous stimulation.","authors":"Sandrine Bédard, Merve Kaptan, Teresa Indriolo, Christine S W Law, Dario Pfyffer, Lindsay Lee, John Ratliff, Serena Hu, Suzanne Tharin, Zachary A Smith, Gary H Glover, Sean Mackey, Julien Cohen-Adad, Kenneth A Weber Ii","doi":"10.1162/IMAG.a.1383","DOIUrl":"10.1162/IMAG.a.1383","url":null,"abstract":"<p><p>Sensory organization at the spinal segment level is commonly inferred from dermatomal maps that assume a fixed correspondence between cutaneous regions and spinal segments. However, based on the complexities of spinal neuroanatomy and neurophysiology, the distribution of sensory signals within the cord may be broader and less segment-specific than dermatomal maps suggest, leaving the segment-level localization of sensory-evoked activity in humans uncertain. Spinal cord functional magnetic resonance imaging (fMRI) is currently the only technique capable of noninvasively mapping sensory activity with high spatial resolution in the human spinal cord. However, its application remains technically challenging and is limited by the uncertainty in segmental localization. In this study, we leveraged recent advancements in spinal cord fMRI, including spinal nerve rootlet-based spatial normalization, to investigate how sensory information is represented and distributed within the human spinal cord during electrocutaneous stimulation of the third digit of the right hand (i.e., C7 dermatome). Forty healthy adults were scanned with electrocutaneous stimulation at four individualized intensities across multiple runs to quantify (i) the rostrocaudal distribution of sensory-evoked activity, (ii) intensity-dependent changes in detectability and localization, and (iii) the effect of normalization strategy on segmental localization. Across participants, stimulation produced activation localized in the lower cervical cord (e.g., C6-C8), with the most consistent segmental localization near C7. Stronger stimulation increased detectability and produced more consistent segmental localization across participants. Importantly, normalization that incorporated nerve rootlet landmarks sharpened localization and improved sensitivity relative to conventional intervertebral disc-based alignment. This highlights the value of functionally relevant anatomical landmarks for group inference in the spinal cord. Responses were strongest in the initial run and attenuated with repetition, suggesting habituation or adaptation that can bias multi-run paradigms if unmodeled. Together, our results define practical acquisition and analysis conditions (e.g., stimulation strength, anatomical alignment strategy, and run structure) under which segment-level spinal sensory responses can be detected, thereby supporting more reliable studies of human spinal cord future basic and translational studies, including pain mechanisms, sensory function, and spinal injury.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13636297/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149119578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expanding the toolkit: OPMs for studying the developing brain.","authors":"Margot J Taylor, Natalie Rhodes","doi":"10.1162/IMAG.a.1387","DOIUrl":"https://doi.org/10.1162/IMAG.a.1387","url":null,"abstract":"<p><p>Tremendous maturation in brain structure and function, underlying very rapid cognitive development, occurs in the early years of life, yet it has been difficult to obtain reliable measures of brain function over this period. A major challenge has been the difficulty of acquiring reliable neuroimaging data from awake young children, who often struggle to tolerate conventional imaging environments or remain still during scanning. Existing approaches each involves important compromises between spatial and temporal resolution, movement tolerance and practicality for use in early childhood. Optically pumped magnetometers (OPMs), a recent advance in magnetoencephalography (MEG) technology, are expanding the developmental neuroimaging toolkit. By enabling adaptable, wearable, and movement-tolerant MEG systems, OPMs retain the excellent spatial and temporal resolution of conventional cryogenic MEG technology while improving suitability for infants, toddlers, and young children. In this commentary, we briefly review the current functional neuroimaging toolkit used across development and discuss how OPMs are transforming the study of the developing brain. We highlight recent applications of OPMs to study early life, their potential for investigating brain-behaviour relationships and social interaction, and their promise for improving inclusion of clinical populations traditionally underrepresented in neuroimaging research. We also outline remaining technical and methodological challenges that should be addressed as the field continues to grow.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13636295/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149119527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iterative delay correction improves breath-hold cerebrovascular reactivity mapping in clinical populations.","authors":"Rebecca G Clements, Fatemeh Geranmayeh, Niamh V Parkinson, Molly G Bright","doi":"10.1162/IMAG.a.1386","DOIUrl":"10.1162/IMAG.a.1386","url":null,"abstract":"<p><p>Cerebrovascular reactivity (CVR), the ability of cerebral blood vessels to dilate or constrict in response to a vasoactive stimulus, is an important measure of cerebrovascular health. Accurate CVR estimation requires accounting for the time required for the vasoactive stimulus to reach each brain region and the time it takes for local arterioles to modulate cerebral blood flow. The temporal search range used to calculate this spatially varying offset can substantially impact CVR estimates, and the appropriate search range may vary across populations, acquisition protocols, and even brain regions. Here, we present an iterative approach for automatically determining the appropriate maximum shift, using breath-hold fMRI data acquired in a cohort of stroke survivors. This approach selectively expands the delay search range only for voxels with estimated delays at the boundary (i.e., near the minimum or maximum shift) until the estimated delay is no longer at the boundary or a predefined value is reached. In the context of stroke, among voxels initially at the boundary, this approach significantly increased the number of voxels with statistically significant CVR (i.e., having a relationship between end-tidal CO₂ and the BOLD signal that is unlikely to be due to random chance). It also resulted in CVR polarity reversals in voxels originally at the early-response boundary and amplified negative CVR values in voxels originally at the late-response boundary, suggesting that using an iterative maximum shift can critically impact CVR interpretation. This approach is broadly applicable beyond stroke, but careful parameter tuning is required, as illustrated by our demonstration of the parameter tuning process for a participant with Moyamoya disease. Together, these findings suggest that iterative delay correction allows for improved CVR assessments in clinical populations.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13636296/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149119540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mind the brain age: How segmentation and template selection reshape structural connectomes.","authors":"Carlo Ferritto, Giulia Lioi, Pierre-Yves Jonin, Julie Coloigner","doi":"10.1162/IMAG.a.1384","DOIUrl":"https://doi.org/10.1162/IMAG.a.1384","url":null,"abstract":"<p><p>Diffusion-weighted MRI samples the directional diffusion of water in vivo, and tractography uses this information to reconstruct brain fiber pathways. Mapping streamlines to an anatomical parcellation yields structural connectomes. However, in older adults, where white matter alterations and atrophy are common, the choice of reference template and tissue segmentation could be particularly consequential for obtaining accurate, interpretable structural connectomes. Using a conventional pipeline, we evaluated how these two factors, the normalization template and the segmentation used to constrain anatomically guided tractography, affect connectome estimates in cognitively healthy elderly participants. These methodological choices produced systematic and significant differences in network topology and their relationships with clinically relevant variables across standard connectome measures, particularly in patients with white matter hyperintensities. Age-appropriate normalization and lesion-aware anatomically constrained tractography yielded networks with more plausible anatomy and more consistent relationships with cognition and imaging measures, whereas unconstrained tracking inflated density without improving interpretability. These findings demonstrate that structural connectome outcomes are contingent upon template and segmentation selection. We, therefore, advocate for explicit reporting of these methodological parameters and recommend the use of age-appropriate templates combined with white matter lesion-aware segmentation incorporating anatomically informed constraints.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13628500/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149119574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brain network differences in second language learning depend on individual competencies.","authors":"Nicole H Skieresz, Sandy C Marca, Micah M Murray, Thomas P Reber, Nicolas Rothen","doi":"10.1162/IMAG.a.1379","DOIUrl":"https://doi.org/10.1162/IMAG.a.1379","url":null,"abstract":"<p><p>Integrating new words into an existing semantic network is a core challenge of second language (L2) acquisition. We investigated how evidence-based learning strategies and individual performance relate to the neurocognitive dynamics of vocabulary learning. Eighty-three adults proficient in German or French learned 48 Finnish (L2) nouns over 14 days using a mobile app that systematically varied retrieval practice, corrective feedback, multisensory learning, and distributed learning. Before and after training, EEG was recorded during a translation recognition task designed to elicit the N400, an index of semantic integration. Vocabulary accuracy increased from 0.41% pre-learning to 75.5% post-learning (<i>d_z</i> = 3.96), and the N400 incongruity effect increased significantly, <i>F</i>(1, 75) = 99.52, <i>p</i> < .001, η<i>²_g</i> = .32, reflecting successful integration of new L2 words into the mental lexicon. High performers showed larger N400 responses, consistent with more differentiated semantic processing. In addition, performance group differences emerged in event-related potential (ERP) template-map preponderance (i.e., the proportion of epoch time points assigned to a given template map), indicating differences in processing dynamics and network configurations. Despite systematic manipulation of learning strategies, no single approach yielded consistent behavioral or neural advantages, suggesting that overall exposure and cumulative practice, rather than any specific strategy, may have been primary contributors to the observed learning gains. ERP template-map analyses further revealed that learning not only increased neural responses but also shifted map preponderance within the N400 window as a function of Session and Congruency, indicating a qualitative reorganization of semantic processing. These findings suggest that vocabulary learning success is more closely related to the degree of semantic integration than to any single instructional strategy.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13628499/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149119476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxygen extraction fraction mapping between normal cognition and mild cognitive impairment in older adults using quantitative BOLD.","authors":"Linh N N Le, Gregory J Wheeler, Nicholas P Blockley, Evan Fletcher, Youngkyoo Jung, Sarah E T Farias, Brandon Gavett, Charles DeCarli, Audrey P Fan","doi":"10.1162/IMAG.a.1378","DOIUrl":"10.1162/IMAG.a.1378","url":null,"abstract":"<p><p>Oxygen extraction fraction (OEF) represents the proportion of oxygen utilized by the brain from the blood and is a sensitive biomarker in understanding the vascular interplay between oxygen supply and demand. Alterations in OEF are increasingly recognized in normal aging and the pathophysiology of many neurological disorders, including Alzheimer's disease and cognitive impairment. Here, we aimed to assess regional OEF MRI in older adults and investigate its relationship with mild cognitive impairment (MCI) and normal aging using a Variational Bayesian quantitative BOLD (qBOLD) framework. The qBOLD model leverages a biophysical relationship between OEF, deoxygenated blood volume (DBV), and the reversible transverse relaxation rate (R₂ ^') to extract parameter values from asymmetric spin echo (ASE) MRI scans. The reliability of these parameter estimates was enhanced by Variational Bayesian inference, which incorporates prior distributions that we optimized in numerical simulation. We then applied this model to a cohort of older adults (N = 70) from the Alzheimer's Disease Research Center (ADRC) at the University of California, Davis, including 58 cognitively normal (CN) and 12 amnestic mild cognitive impaired (MCI) participants. Our findings revealed a trend of elevated OEF across many cortical brain regions in the MCI group. Additionally, we identified regional positive associations between OEF and age in the MCI group, significantly in the left inferior parietal region ( <math><mrow><mi>β</mi> <mo>=</mo> <mn>0.88</mn> <mo>±</mo> <mn>0.23</mn> <mo>,</mo> <mo> </mo> <mi>T</mi> <mo>=</mo> <mn>3.75</mn> <mo>,</mo> <mo> </mo> <mi>P</mi> <mo>=</mo> <mn>0.0004</mn></mrow> </math> ). Furthermore, the relationship between OEF and episodic memory in the right parahippocampal region differed significantly between two diagnostic groups (negative for CN and positive for MCI) ( <math><mrow><mi>β</mi> <mo>=</mo> <mn>0.09</mn> <mo>±</mo> <mn>0.02</mn> <mo>,</mo> <mo> </mo> <mi>T</mi> <mo>=</mo> <mn>3.77</mn> <mo>,</mo> <mo> </mo> <mi>P</mi> <mo>=</mo> <mn>0.0004</mn></mrow> </math> ). This work adopts a novel qBOLD MRI framework for studying OEF changes in cognitive impairment as a potential biomarker for monitoring pathophysiology in aging and dementia.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13626017/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149119542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of the left intraparietal sulcus in the comprehension of action intensity described in sentences.","authors":"Hiroshi Shibata, Kosaku Takahashi, Mitsuki Niida, Kenji Ogawa","doi":"10.1162/IMAG.a.1371","DOIUrl":"10.1162/IMAG.a.1371","url":null,"abstract":"<p><p>From an embodied cognition perspective, semantic processing is assumed to involve sensorimotor representations. The present study used functional magnetic resonance imaging to investigate whether comprehension of action intensity described in sentences is associated with neural representations shared with action execution, particularly those related to grip force. In the execution task, participants gripped their right hand with either high or low force. In the language task, participants evaluated the action intensity described in the sentences. We examined four regions of interest (ROIs): the left primary somatosensory cortex, left primary motor cortex, left dorsal premotor cortex, and the left intraparietal sulcus (LIPS). Multivoxel pattern analysis was used to assess whether intensity information could be decoded within and across tasks. In the execution task, intensity differences were reliably decoded from multivoxel activity patterns across all four regions. In the language task, significant decoding of intensity was observed only in the LIPS. Cross-classification between the execution and language tasks did not reach significance in the primary analysis across the four regions and was associated with low effect sizes. However, exploratory analyses using smaller ROIs revealed significant cross-decoding and moderate effect sizes in the LIPS. These findings suggest that the comprehension of action intensity is associated with higher-level intensity-related representations rather than with neural representations that are closely tied to low-level motor execution. Overall, the results do not support strong embodied accounts, which assume the direct reinstatement of low-level motor execution processes during language comprehension. However, these findings suggest that partially shared higher-level representations of intensity may exist between action execution and language processing.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13618355/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149076993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic DWI detects respiratory modulation of brain parenchymal hydrodynamics.","authors":"Jianing Zhang, Elodie Foster, Adam M Wright, Xiaopeng Zhou, Qiuting Wen","doi":"10.1162/IMAG.a.1369","DOIUrl":"10.1162/IMAG.a.1369","url":null,"abstract":"<p><p>The circulation of cerebrospinal fluid (CSF) within the brain parenchyma and its exchange with interstitial fluid (ISF) are essential for maintaining homeostasis and clearing interstitial waste. However, the physiological forces driving parenchymal hydrodynamics remain unclear. Cardiac pulsation alone may be insufficient to drive parenchymal flow, while respiration has emerged as an additional contributor. To date, however, most respiration-related studies have focused on the ventricular system and spinal canal, leaving its influence on parenchymal hydrodynamics-the site of waste production-largely unexplored. In this study, we investigated whether parenchymal hydrodynamics are coupled with respiration during normal breathing, and how this coupling compares with that driven by cardiac pulsation. We used dynamic diffusion-weighted imaging (dynDWI) with a b-value of 150 s/mm² to capture incoherent fluid motion, quantified using the apparent diffusion coefficient (ADC). Respiration and cardiac signals were simultaneously recorded using a respiratory belt and finger photoplethysmography (PPG). Temporal coupling strength and time delay between parenchymal hydrodynamics and physiological signals were assessed using TRACC-PHYSIO (Time-domain Resolution-Aligned Cross-Correlation) for physiological coupling. We found that temporal ADC fluctuations in the parenchyma were coupled to respiration, with a latency of 0.7 seconds, and exhibited a gray-to-white matter propagation pattern. Spatial coupling patterns differed between respiration and cardiac pulsation: respiration coupling was stronger in gray and white matter than in the perivascular subarachnoid space (PVSAS) and lateral ventricles (LV), whereas cardiac coupling predominated in the PVSAS and LV. Rebinning dynDWI into respiration cycles revealed parenchymal ADC peaked during inhalation and reached a minimum during exhalation. Together, these findings suggest that respiration contributes to driving parenchymal hydrodynamics and fluid-driving forces vary spatially across brain regions, with respiration and cardiac pulsation playing complementary roles in regulating brain fluid dynamics.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13613705/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149066573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}