Applications Of MR Spectroscopic Imaging And Diffusion Tension Imaging In Traumatic Brain Injury

PartⅠRelative quantitative 3．0T MR Spectroscopy imaging in frontal lobe of normal human brainPurpose: Using MRSI to evaluate the brain metabolite of volunteers, and elucidate the difference of neurometabolite markers in the normal adult brain among age and gender.. Materials and methods: Using a GE signa VH/i 3．0T super conduct MR unit, 40 cases of volunteers (20 men, 20 women; age range, 20-59 years; mean age 39 years) were performed with 2-D multi-voxel PRESS 144 to explore the metabolite of the brain. Then compare the difference of neurometabolite markers among parenchyma of hemisphere, gender and the gray/white matter by the relative quantification and pseudocolor images of NAA,Cho,Cr,Glx,mI. Functool software package was used for post-processing of spectrum. Results: No significant differences can be founded in the neurometabolite markers between right and left parenchyma of frontal lobe in normal adult, and there no neurometabolite markers difference between gender in normal adults. The difference between gray and white matter in the front lobe is significant in normal adult. NAA/Cr decline and Cho/Cr increase was found with advancing age. Conclusion: By spectrum, relative quantification can be used to evaluate the difference of brain metabolite. The neurometabolite markers is influenced by age, and neurometabolite markers between white matter and gray matter is different, and these factors shoud be considered when studying MRSI of the brain.PartⅡApplications of MRSI in acute stage of traumatic brain injuryPurpose: To investigate the characteristic of MRSI in patients suffered traumatic brain injury, and the correlation between neurometabolite markers of the patients and their GCS. Material and methods: We report MRI and proton magnetic resonance spectroscopy studies of 36 head-injured patients performed once the patients were clinically stable (mean 8 days after injury, range 1-18 days). Proton magnetic resonance spectra were acquired from white matter and gray matter of hibateral frontal lobe that on conventional MRI appeared normal using 2D MRSI with 3．0T. 30 volunteer as contronl were studied at the same time. Results: The brain N-acetylaspartate/creatine ratio was reduced and the choline/creatine ratio was increased.compared with controls. When the severity of the injury was assessed using theGlasgow coma scale, the increase in the choline/creatine ratio was significant even inthe moderate and severe injured group. Furthermore, there was a significantcorrelation between the severity of head injury and the N-acetylaspartate/choline ratio.Conclusion: We conclude that there is an early reduction in N-acetylaspartate and anincrease in choline compounds in normal-appearing white matter which correlate withhead injury severity, and that this may provide a usful tool that can tell the severity ofthe brain injury in patients with traumatic brain injury.PartⅢApplications of MRSI in restoration stage of traumatic brain injuryPurpose: The aim of the present study was to assess change in neurometabolite markers of brain injury during the recovery period following TBI, and the correlation between neurometabolite markers of the patients and their GOS at six months.Material and methods: We studied 24 TBI patients at 3 and 6 months postinjury and 30 controls. We used using 2D MRSI with 3．0T to quantify NAA/Cr, Cho/Cre, and Cho/NAA in gray matter and white matter in hibateral frontal lobe remote from the primary injury focus. Results: NAA/Cr continued to fall between postinjury and 3 months and Cho/Cr, Cho/NAA continued to increase indicating continuing neuronal loss, metabolic dysfunction, or both. Between 3 and 6 months, NAA/Cr increased and Cho/Cr, Cho/NAA decreased suggesting metabolic recovery. Conclusion: 1H-MRS offers a noninvasive approach to assessing neuronal injury and inflammation following TBI, and may provide unique data for patient management and assessment of therapeutic efficacy.PartⅣStudy of anisotropy of normal adult brain by using diffusion tensor imagingPurpose: To investigate the difference of the different part of the brain, and elucidate the difference of anisotropy in the normal adult brain among age and gender.Material and methods: 40 healthy adult volunteers(20 men, 20 women; age range, 20-59 years; mean age 39 years) were studied using MR diffusion tensor imaging. The FA values and ADC values were measured in the different parts of the brain. The ROIs were external capsule, anterior limb of the internal capsule, posterior limb of the internal capsule, genu of corpus callosum, splenium of corpus callosum, semioval center, lentiform nucleus, caudate nucleus, thalamus and cerebrospinal fluid. Results: There was no significant difference in FA or ADC between male and female or between the right ang left hemisphere. There was significant difference in FA or ADC between the ROIs of this study. The FA value of the splenium of the corpus callosum is highest, and external capsule is the lowest in the white matter of the brain. FA value decline and ADC value increase was found with advancing age. Conclusion: FA value can be used to quantitate anisotropy of the different part of the brain. There was a tenuous FA value reduction and ADC value increase with increasing age.PartⅤApplications of DTI in traumatic brain injuryPurpose: Our objective was to determine the changes in anisotropic diffusion in TBI, and to determine correlation of the changes in anisotropic diffusion with acute Glasgow coma scale (GCS) and/or GOS at six month. Material and methods: 36 patients (12 Female; mean age, 37 years) were evaluated. Apparent diffusion coefficients (ADCs) and fractional anisotropy (FA) values were measured at multiple locations and correlated with clinical scores. Results were compared with those of 30 healthy control subjects. Results: ADC values were significantly reduced within the splenium. FA values were significantly reduced in the internal capsule, semioval center and splenium. FA values were significantly correlated with GCS and GOS at six month for the internal capsule and splenium.There were no significant change in ADC values in the brain. No correlation was found between ADC of the internal capsule and GCS/GOS. Conclusion: DTI reveals changes in the white matter that are correlated with both acute GCS and GOS at six month. DTI may be a valuable biomarker for the severity of tissue injury and a predictor for outcome.