Zang YF papers
Reliability and validity enhancements of intrinsic metrics via quantitative T2* fluctuation from multi-echo fMRI
Neuroimage. 2026 Aug 7:122160. doi: 10.1016/j.neuroimage.2026.122160. Online ahead of print.
ABSTRACT
Functional magnetic resonance imaging (fMRI) is the most commonly used technique for non-invasive exploration of human cognition and neuroscience. Conventional T2*-weighted single-echo resting-state fMRI (SE-rfMRI) is limited by signal loss in regions prone to susceptibility artifacts and inseparable confounding from non-neuronal baseline (i.e., initial signal intensity S0) fluctuations. While multi-echo optimally combined rfMRI (ME-OC) effectively mitigates signal loss, confounding from S0 fluctuations remains unaddressed. Here, we leverage quantitative T2* fluctuation from ME-rfMRI to derive intrinsic functional metrics that are biophysically cleaner and more robust. Across both cortical and subcortical brain regions, we systematically evaluated the test-retest reliability and functional validity of two key local metrics, amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo), derived from our proposed method against those from conventional SE-rfMRI and ME-OC. In subcortical regions, T2*-derived metrics showed the highest mean ICCs among the three signal representations for both ALFF (ICC = 0.67, 0.66, and 0.54) and ReHo (ICC = 0.73, 0.67, and 0.63) for T2* fluctuation, ME-OC, and SE-rfMRI, respectively. A similar regionally selective pattern was observed in cortical areas susceptible to magnetic field inhomogeneities, including the orbitofrontal cortex (ALFF ICC = 0.87, 0.75, and 0.82), insula (0.83, 0.61, and 0.71), and temporal pole (0.80, 0.73, and 0.79) for T2* fluctuation, ME-OC, and SE-rfMRI, respectively. In terms of functional validity, ALFF from T2* fluctuation uniquely revealed significant condition-related differences in the right putamen, inferior frontal gyrus, and suborbital sulcus, which both ME-OC and SE-rfMRI failed to detect. Together, our findings suggest that quantitative T2*-derived metrics may provide a reliable and more biophysically specific characterization of intrinsic fMRI signal fluctuations, particularly in subcortical and susceptibility-prone cortical regions, and may complement conventional approaches in future research applications.
PMID:42567430 | DOI:10.1016/j.neuroimage.2026.122160
Cumulative Triglyceride and Remnant Cholesterol Increase Arterial Stiffness: A Prospective Cohort Study
Biomed Environ Sci. 2026 Jun 20;39(6):641-651. doi: 10.3967/bes2026.044.
ABSTRACT
OBJECTIVE: Dyslipidemia has been linked to increased arterial stiffness. However, few studies have comprehensively assessed the cumulative effects of lipid profiles on arterial stiffness.
METHODS: Based on the initial recruitment of 7,134 participants from the China-PAR cohort, we finally included 6,717 participants with up to four repeated lipid measurements between baseline (1998-2008) and the most recent follow-up (2018-2020). Cumulative exposure to total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, and remnant cholesterol (RC) was estimated using the area under the curve method. Arterial stiffness was measured in 2018-2020 using the arterial pressure-volume index (API) and the arterial velocity-pulse index (AVI), which reflect the stiffness of peripheral and central arteries, respectively.
RESULTS: Participants (mean age: 51.4 ± 10.3 years) included 2,598 men (38.68%), with a mean cumulative lipid exposure duration of 14.02 years. Cumulative TG, HDL-C, and RC were significantly associated with API levels, with adjusted β s (95% confidence intervals [ CIs]) of 2.31 (1.53, 3.08), -1.14 (-2.24, -0.04), and 2.39 (1.52, 3.25), respectively, for the highest quartile compared with the lowest quartile. Restricted cubic splines showed nonlinear associations of cumulative TG and RC with API and a linear association for HDL-C (all P < 0.05). For AVI, only cumulative HDL-C showed a significant inverse association, with an adjusted β (95% CI) of -1.16 (-2.12, -0.21) for the highest quartile, and a nonlinear association was observed ( P < 0.05).
CONCLUSION: Long-term cumulative TG and RC were associated with increased peripheral arterial stiffness but not central arterial stiffness, and cumulative HDL-C was negatively associated with both peripheral and central arterial stiffness. These findings underscore the importance of long-term TG and RC control along with maintaining adequate HDL-C levels.
PMID:42417233 | DOI:10.3967/bes2026.044