Reduced deep regional cerebral venous oxygen saturation in hemodialysis patients using quantitative susceptibility mapping

Abstract

Cerebral venous oxygen saturation (SvO₂) is an important indicator of brain function. There was debate about lower cerebral oxygen metabolism in hemodialysis patients and there were no reports about the changes of deep regional cerebral SvO₂ in hemodialysis patients. In this study, we aim to explore the deep regional cerebral SvO₂ from straight sinus using quantitative susceptibility mapping (QSM) and the correlation with clinical risk factors and neuropsychiatric testing_. 52 hemodialysis patients and 54 age-and gender-matched healthy controls were enrolled. QSM reconstructed from original phase data of 3.0 T susceptibility-weighted imaging was used to measure the susceptibility of straight sinus. The susceptibility was used to calculate the deep regional cerebral SvO₂ and compare with healthy individuals. Correlation analysis was performed to investigate the correlation between deep regional cerebral SvO₂, clinical risk factors and neuropsychiatric testing. The deep regional cerebral SvO₂ of hemodialysis patients (72.5 ± 3.7%) was significantly lower than healthy controls (76.0 ± 2.1%) (P < 0.001). There was no significant difference in the measured volume of interests of straight sinus between hemodialysis patients (250.92 ± 46.65) and healthy controls (249.68 ± 49.68) (P = 0.859). There were no significant correlations between the measured susceptibility and volume of interests in hemodialysis patients (P = 0.204) and healthy controls (P = 0.562), respectively. Hematocrit (r = 0.480, P < 0.001, FDR corrected), hemoglobin (r = 0.440, P < 0.001, FDR corrected), red blood cell (r = 0.446, P = 0.003, FDR corrected), dialysis duration (r = 0.505, P = 0.002, FDR corrected) and parathyroid hormone (r = −0.451, P = 0.007, FDR corrected) were risk factors for decreased deep regional cerebral SvO₂ in patients. The Mini-Mental State Examination (MMSE) scores of hemodialysis patients were significantly lower than healthy controls (P < 0.001). However, the deep regional cerebral SvO₂ did not correlate with MMSE scores (P = 0.630). In summary, the decreased deep regional cerebral SvO₂ occurred in hemodialysis patients and dialysis duration, parathyroid hormone, hematocrit, hemoglobin and red blood cell may be clinical risk factors.

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