Deep gray matters iron deposition is positively associated with white matter hyperintensity in hypertension.

The association and underlying mechanisms between iron deposition and white matter hyperintensity (WMH) remain unclear. In this study, quantitative susceptibility mapping (QSM) was used to quantify deep gray matters iron deposition and to explore the association from both global and regional perspectives. A total of 84 patients with hypertension and 26 healthy controls underwent a strategically acquired gradient echo (STAGE) protocol, and the multi-echo data were used to reconstruct QSM images. The susceptibilities were used to describe iron content. Global region (RI) susceptibilities were measured in regions of interest, and age-related thresholds were used to determine high-iron content region (RII) susceptibilities. Compared with healthy controls, hypertension had higher total WMH scores and regional scores (all p = .001) and higher susceptibilities using the RI or RII analysis (all p < .05). In healthy controls, there was no significant association between susceptibilities and WMH scores. In hypertension, the susceptibilities of deep gray matters were positively correlated with WMH scores (RI analysis: right putamen; RII analysis: bilateral caudate nucleus head, putamen, red nucleus, substantia nigra, and dentate nucleus; age and education corrected p < .05). These findings suggest that iron deposition in deep gray matters was positively associated with WMH in hypertension, especially using the RII analysis.

Quantitative Susceptibility Mapping of Brain Iron Relating to Cognitive Impairment in Hypertension.

BACKGROUND: Hypertension (HTN) might impair cognition. Brain iron deposition correlates with cognitive impairment. The relationship between brain iron and cognition in HTN patients is less clear. PURPOSE: To measure brain susceptibility in HTN patients using quantitative susceptibility mapping (QSM) and to explore the relationship between brain iron and cognition. STUDY TYPE: Retrospective cross-sectional study. SUBJECTS: Sixty HTN patients (35 with mild cognitive impairment [MCI] and 25 without MCI) and 24 age, gender, and education matched controls. FIELD STRENGTH/SEQUENCE: 3 T; strategically acquired gradient echo (STAGE) imaging protocol for QSM analysis. ASSESSMENT: All subjects underwent Montreal Cognitive Assessment (MoCA) scoring of visuospatial/executive, naming, attention, abstraction, language, delayed memory, and orientation functions. HTN patients were divided into two groups (with and without MCI) depending on the MoCA score. Regions of interest (ROIs) were manually demarcated on the STAGE images by three independent radiologists and susceptibility were determined for bilateral frontal white matter, parietal white matter, occipital white matter, caudate nucleus (CN), putamen (PU), globus pallidus (GP), thalamus (TH), red nucleus (RN), substantia nigra (SN), and dentate nucleus (DN). STATISTICAL TESTS: Analysis of variance with post-hoc least significant difference (LSD) tests and Pearson correlation coefficients (r). A P-value <0.05 was considered to be statistically significant. RESULTS: The susceptibility was significantly different in CN, PU, and DN among the three groups. The susceptibility of right CN and left PU were correlated with MoCA scores (r = -0.429 and r = -0.389, respectively). The susceptibility of left PU was also correlated with delayed memory scores (r = -0.664). The susceptibility of left and right GP were correlated with naming scores (r = -0.494 and r = -0.446, respectively) and the susceptibility of left DN were correlated with visuospatial/executive scores (r = 0.479). DATA CONCLUSION: QSM measured brain iron was significantly higher in CN, PU, and DN in HTN patients. Cognitive impairment was correlated with regional brain iron deposition. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 3.