Acute Effects Fo Low And High Doses Of Alcohol Consumption On Healthy Human Brains: 1HMR Spectroscopy And Diffusion Tensor Imaging Studies

Purpose:To assess the values of diffusion tensor imaging (DTI) and MRS in detecting the acute effects of alcohol on healthy young adult human brains. This study was also to correlate results of DTI and MRS in healthy subjects before and after alcohol intake.Materials and Methods: Sixteen healthy volunteers (age 25-33y,man=8,woman=8) were randomly divided into two groups: low doses group(0.45 g/kgbw, n=8) and high doses group( 0.65 g/kgbw, n=8).They were studied with conventional MR imaging, MRS and DTI using the same imaging parameters prior to and 1 h, 2 h, 3 h after the initiation of alcohol administration so that each subject could serve as its own control. Multivoxel Chemical shift imaging (CSI) and DTI were performed on a 1.5 T MRI scanner. FA and ADC values were measured in centrum semiovale, frontal lobe, genu corporis callosi, splenium corporis callosi, internal capsule, external capsule, thalamus and vermiform process of cerebellum. Choline (Cho), creatine and N-acetylaspartate (NAA) were detected in centrum semiovale. A region of interest was positioned in the white matter of the Multivoxel CSI data were processed and the metabolite ratios estimated. DTI parameters corresponding to the exact region of tissue excited by CSI were obtained. Mean spectroscopy data and DTI values for each subject were correlated. Statistical analysis was performed by SPSS 13.0 software.Result:1. The changes of FA values and ADC values in different part of human brains: Compared with pre-alcohol intake, mean FA values in frontal lobe and thalamus were increased (P<0.01 respectively), and ADC reduced after alcohol intake (P<0.01 respectively), and mean FA and ADC in low and high doses began to change at difference time point (2 h and 3 h respectively) after drinking. Mean FA values were higher (P<0.05) and the ADC values were lower (P>0.05) in frontal lobe in high doses group than that in low doses group. There were no significant differences in both of the the FA and ADC values in thalamus and other locus of cerebrum (genu corporis callosi, splenium corporis callosi, internal capsulesa, external capsulesa, and vermiform process of cerebellum) (P>0.05, all). Mean ADC values in centrum semiovale reduced after alcohol intake than that in pre-alcohol intake (P<0.01), and mean FA values increased (P<0.01) after alcohol intake.2. The changes of MRS in centrum semiovale after high and low does of alcohol intake: Mean NAA/Cr values and Cho/Cr value in centrum semiovale increased than that in pre-alcohol intake (P<0.01), and the difference of mean NAA/Cho values were not statistically significant (P >0.05).3. The relationships of DTI and MRS in centrum semiovale: In pre-alcohol intake group, NAA/Cr values in centrum semiovale were correlated to FA and ADC values(r = 0.42 and r =- 0.397, P <0.01, both).NAA/Cho were correlated to FA and ADC values (r =- 0.405 and r = 0.383, P <0.01, both). Cho/Cr were correlated to FA and ADC values (r = 0.704 and r =- 0.655, P <0.01, both). Both in high and low does groups, NAA/Cr values and NAA/Cho values showed weak correlation to FA and ADC values within 3 h after alcohol intake. Cho/Cr showed strong correlation to FA and ADC values in high does group (r = 0.528, r =-0.436, respectively) and in low does group (r = 0.467, r = -0.488, respectively) (P<0.01, all) at 3 h after alcohol intake.Conclusion:1. DTI and MRS can detect changes in brains after acute alcohol consumption not be visible on conventional MRI.2. Cytotoxic brain edema has been shown as one of the main consequences of acute alcohol consumption in this study. The influence of acute high doses alcohol intake in human brain is more sustained than that in low doses group.3. The frontal lobes and thalamus are more vulnerable to the effects of acute alcohol consumption in DTI study.4. The DTI/MRS United Technology used in our study showed NAA/Cho, Cho/Cr were correlated with FA and ADC values respectively, and the correlation between Cho/Cr and FA values, ADC values is strongest in healthy human brains before and after alcohol consumption, which indicated FA values about integrity of nerve fibers and ADC values about diffusion coefficients, while both correlated to Cho about demyelination.