Preliminary study of cerebral venous oxygen saturation in healthy people using MR quantitative susceptibility mapping

Objective: To measure the magnetic sensitive figure of cerebral vein and to evaluate the gender and bilateral difference in normal human cerebral venous oxygen saturation and the correlation with age by MR quantitative susceptibility mapping (QSM). Methods: Sixty right-handed healthy volunteers were enrolled in our study and underwent MRI and susceptibility weighted imaging (SWI) scan to acquire the phase and magnitude image of healthy people from November 2012 to September 2014. The susceptibility mapping(SM) was constructed from phase diagram and amplitude image by the susceptibility mapping imaging and phase artifacts removal toolbox (SMART) software. The region of interest (ROI) of bilateral cerebral veins (cerebral cortical veins, thalamostriate veins, septal veins, internal cerebral veins and basal veins of rosenthal) in SM was outlined manually by signal processing in nuclear magnetic resonance (SPIN). The Wilcoxon test was used to compare the gender-and side-difference of susceptibility measured by cerebral venous oxygen saturation. The Spearman correlation was used to calculate the correlation between the susceptibility of cerebral veins and age. Results: The median susceptibility (extent) of left and right side cerebral cortical veins was 159.16(154.88-164.13)ppb(× 10^-9), 164.61(156.23-168.04) ppb, respectively. The median susceptibility (extent) of left and right side thalamostriate veins was 160.51 (152.14-170.06)ppb, 162.48(153.47-173.66)ppb, respectively. Left were less than the right, and the difference was statistically significant (Z = -3.14, -2.02, P < 0.05). And the difference of two side of other cerebral venous susceptibility had no statistical significance. The median susceptibility (extent) of right cerebral cortical veins, left thalamostriate veins and right septal veins of 22 male was 166.22(159.21-169.99)ppb, 168.65(159.19-174.45)ppb and 153.42(148.10-161.78)ppb, respectively. The corresponding positions of median susceptibility (extent) of 38 female was 161.10(155.06-167.15)ppb, 157.70(151.53-164.41)ppb and 147.52(142.94-154.16)ppb, respectively. The susceptibility of right cerebral cortical vein, left thalamostriate vein, right septal vein of male was significantly different from the females (Z = -2.03, -2.20, -2.33, P < 0.05). Furthermore, we also found that there had positive correlation between age and right thalamostriate vein(r = 0.28, P < 0.05). Conclusion: The magnetic sensitive of the right thalamostriate vein tends to increase along with the age, and some of peoples had difference with bilateral and age. (authors)