MRI‐Based Investigation of Association Between Cerebrovascular Structural Alteration and White Matter Hyperintensity Induced by High Blood Pressure

Abstract

Background High blood pressure (BP) is a common risk factor for cerebral small vessel disease including white matter hyperintensity (WMH). Whether increased BP exacerbates WMH by impacting cerebral vascular morphologies remains poorly studied. Purpose To determine the relationships among high BP, cerebrovascular morphologies, and WMH in elderly individuals. Study Type Cohort. Subjects Eight hundred sixty‐three participants (54.2% female) from the Taizhou Imaging Study without clinical evidence of neurologic disorders were included in the analyses. Field Strength/Sequence 3.0 T; time‐of‐flight magnetic resonance angiography (TOF MRA); T2 fluid‐attenuated inversion recovery (FLAIR); T1 magnetization‐prepared rapid gradient‐echo; gradient echo T2*‐weighted; diffusion tensor imaging; pulsed arterial spin labeling. Assessment Cerebrovascular morphologic measurements were quantified based on the TOF MRA images, including vessel density, radius, tortuosity, and branch number. WMH lesion volumes (WMHV) and WMH lesion counts (WMHC) were calculated automatically based on the T2 FLAIR images. Statistical Tests Multivariable linear regression analysis and path analysis with a linear single‐mediator model were employed. A P value <0.05 was considered statistically significant. Results Higher BP, especially diastolic BP, was significantly correlated with lower cerebrovascular density (β = −104) and lower branch numbers (β = −0.02). Although decreased tortuosity (β = −1.25) and increased radius (β = 93.8) were correlated with BP, no significant relationship of tortuosity (β = −4.6 × 10−4, P = 0.58) or radius (β = 0.03, P = 0.08) with BP in small vessels was found. The proportion of small vessels decreased as BP increased (SBP: β = −6.6 × 10−4; DBP: β = −9.0 × 10−4). Similarly, increased WMHV and WMHC were associated with decreased vessel density (volumes: β = −24, counts: β = −127), decreased tortuosity (volumes: β = −0.08, counts: β = −0.53), and increased radius (volumes: β = 12.6, counts: β = 86.6). Path analyses suggested an association between high BP and WMHs that were mediated by cerebrovascular morphologic changes. Data Conclusion Structural alterations of cerebral vessels induced by high BP are correlated with WMH. This result suggested that elevated BP might be one of the pathophysiological mechanisms involving in the co‐occurrence of cerebrovascular alteration and small vessel disease. Level of Evidence: 1 Technical Efficacy Stage: 1

Day to Day Blood Pressure Variability Associated With Cerebral Arterial Dilation and White Matter Hyperintensity

“…Moreover, it has been suggested that elevated BP may affect CSVD by reshape the large intracranial arteries. 42 …”

“…Moreover, it has been suggested that elevated BP may affect CSVD by reshape the large intracranial arteries. 42 Nevertheless, it is more likely that the above 2 processes interact with each other, forming a vicious circle, which promotes the growth of WMH. A similar vicious cycle related to morphological modifications between large and small arteries caused by hypertension has been reported previously.…”

Modification of cerebrovascular morphologies during different stages of life

“…Cerebral vessel segmentation and feature extraction were completed on TOF MRA scans using the existing method with following steps: 17 1) vascular structures were enhanced using the Jerman Enhancement Filter; 18 2) the level-set based method was used to obtain vessel segmentation; 3) segmentation results were firstly checked by B.Y.Z and B.W. Segmentations with too few vascular branches, nonvascular tissue remnants, or incorrect vascular branch adhesions were re-segmented by adjusting the segmentation parameters.…”

Editorial for “MRI‐Based Investigation of Association Between Cerebrovascular Structural Alteration and White Matter Hyperintensity Induced by High Blood Pressure”

“…In this issue of Journal of Magnetic Resonance Imaging, Boyu Zhang and colleagues studied the connection between hypertension, cerebrovascular morphology, and WMH burden. 3 In their study, the authors used MRI data from 863 participants (465 had hypertension) from Taizhou Imaging Study and quantified the white matter lesion burden using automated lesion prediction algorithm based on T2-weighted fluid attenuated inversion recovery (FLAIR) images. Brain vascular morphology was studied using time-of-flight MR angiography (TOF MRA) for vessel density, tortuosity (describing the healthy curvature of individual blood vessels), branch numbers, and radius.…”

“…However, majority of CSVD cases are sporadic, raising from vascular risk factors including hypertension. In this issue of Journal of Magnetic Resonance Imaging , Boyu Zhang and colleagues studied the connection between hypertension, cerebrovascular morphology, and WMH burden 3 …”