Abstract
ObjectiveTo preliminarily explore subclinical brain alterations in an asymptomatic carotid vulnerable plaque group based on intravoxel incoherent motion (IVIM) imaging through voxelwise comparison in the whole brain.Materials and MethodsForty-nine elderly participants underwent multi-b-value DWI, of whom 24 participants with asymptomatic carotid vulnerable plaques and <50% stenosis served as the test group, while the rest served as the healthy control group. After fitting the double-exponential model, slow ADC (Ds) and the fraction of fast ADC (f) values of the whole brain were obtained, which then were compared in a voxelwise manner by two-sample t-test. Multiple comparisons were corrected by the family-wise error (FWE) method with a corrected threshold of P < 0.05. Pearson correlations between IVIM parameters in altered brain regions and blood pressure, glucose, lipid, and homocysteine were calculated.ResultsFor the test group, the Z-normalized Ds values were significantly higher in the left median cingulate and paracingulate gyrus (DCG.L), posterior cingulate gyrus (PCG. L), and left precuneus gyrus (PCUN.L) (cluster size = 156) and in the left middle frontal gyrus (MFG.L), orbital middle frontal gyrus (ORBmid.L), and superior frontal gyrus (SFG.L) (cluster size = 165); the Z-normalized Ds values were significantly lower in the right middle temporal gyrus (MTG.R) and inferior temporal gyrus (ITG.R) (cluster size = 116); and the Z-normalized f-values were significantly lower in the MTG.R and ITG.R (cluster size = 85) (p < 0.05, FWE correction). LDL-C was negatively correlated with the Z-normalized Ds values in the DCG.L, PCG.L, and PCUN.L (r = 0.601, p = 0.002). LDL-C was positively correlated with the Z-normalized f-value in the MTG.R and ITG.R (r = 0.405, p = 0.05). Systolic blood pressure was positively correlated with the Z-normalized Ds values in the MFG.L, ORBmid.L, and SFG.L (r = 0.433, p = 0.035).ConclusionThis study was the first to detect subclinical brain alterations in asymptomatic carotid vulnerable plaque group through IVIM using whole-brain voxelwise comparisons, which were partially correlated with blood pressure and lipids. Thus, IVIM might be utilized as a noninvasive biomarker of microvascular and microstructural brain changes in the asymptomatic carotid vulnerable plaque group.
Highlights
Asymptomatic carotid artery stenosis is common in the general population; its prevalence is 6% in elderly male people and 4.4% in elderly female people (de Weerd et al, 2010)
The Z-normalized Ds values were significantly lower in the right middle temporal gyrus (MTG.R) and inferior temporal gyrus (ITG.R), and the Z-normalized f -values were
We found that the cerebral regions with altered Ds values and f values in the carotid vulnerable plaque group were mostly related to cognition and emotion and anoxia-sensitive regions
Summary
Asymptomatic carotid artery stenosis is common in the general population; its prevalence is 6% in elderly male people and 4.4% in elderly female people (de Weerd et al, 2010). Carotid endarterectomy has a much lower efficiency in reducing the risk of stroke in asymptomatic patients than in symptomatic patients (Halliday et al, 2004). This difference in absolute risk reduction after carotid endarterectomy suggests the importance of plaque vulnerability, except for plaque size and lumen occlusion. Several clinical studies showed that in addition to the degree of carotid artery stenosis, the thickness of the carotid intima-media and the size of the hypoechoic area in plaques reflect the vulnerability of carotid plaques, which is closely associated with the occurrence of cerebral infarction (Moroni et al, 2016). No causal correlation has been identified from his association, the existence of carotid plaques may be regarded as an important risk factor for subclinical brain injury (Moroni et al, 2016)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
