Quantitative Evalution Of Multiple System Atrophy-cerebellar By MR Diffusion Tensor Imaging:a Preliminary Study

ObjectiveTo perform a quantitative assessment of brain tissue damage using Magnetic resonance diffusion tensor imaging (MR DTI) and to explore the clinical correlation for micro structural changes of pons-cerebellar system, the nigrostriatal projection system and the cerebral hemisphere in MSA-cerebellar patients。To evaluate the benefits of DTI color FA maps and directional color-coded maps, compared to conventional magnetic resonance imaging (MRI).Methods15cases of MSA-C patients and15healthy volunteers underwent conventional MRI and DTI scans using U.S.A GE company Signa HDX3.0T MR scanner. Fractional anisotropy (FA) and mean diffusion (MD) value of14regions of the brain, namely-pons, cerebellar peduncle, white matter of cerebellar hemisphere, cerebellar vermis, head of caudate nucleus, putamen, globus pallidus, thalamus, anterior cingulate, posterior cingulate, anterior central gyrus, gyrus centralis posterior, frontal lobe and occipital lobe white matter were measured. The differences in these2DTI parameters between the MSA-C and normal group involving the above mentioned14regions of interest was evaluated..According to the conventional MRI pontine T2WI sequences the following "hot cross bun signs" were seen in the MSA-C group-"hot cross bun sign"0(conventional MRI normal),"hot cross bun sign"2、"hot cross bun sign"5; Each subject in the MSA-C group and the normal control group were evaluated using color DTI FA maps and directional color-coded maps to demonstrate distribution differences of the pons,cerebellar peduncle fibers; The evaluation involved2steps, the first step, compared the differences among the MSA-C group and normal group in pons, cerebellar peduncle fibers using the color FA maps and the directional color-coded map; The second step, compared differences in the pons, cerebellar peduncle fibers of conventional MRI and color FA maps, directional color-coded diagram between MSA-C group with "hot cross bun sign "0(conventional MRI normal), and normal group.Results(1) the FA、MD values of equivalent sides of the brain in both the groups showed no significant difference.(2) The MSA-C group showed statistically significant changes compared to the normal group, in the following aspects:increased value of MD and decreased value of FA in pons, cerebellar peduncle, white matter of cerebellar hemisphere, cerebellar vermis, frontal lobe: increased value of both MD and FA in putamen.(3) MSA-C group compared with the normal group on the FA maps, showed different degrees of reduction in the distribution of red fibers in bilateral cerebellar peduncle and pons, reduce the extent of MSA-C type group of "cross sign"0(conventional MRI normal), MSA-C type group of "cross sign"2、MSA-C type group of "cross sign"5.; compared with each MSA-C group and the normal group using directional color-coded map, showed different degrees of reduction in cerebellar peduncle of different green bilateral and in pon of red fiber, and we can see the degrees damagey uniformly of fiber in cerebellar peduncle, pons; they reduce the extent of MSA-C type group of "cross sign"0(conventional MRI normal), MSA-C type group of "cross sign"2、 MSA-C type group of "cross sign"5. (4) compared with MSA-C type group of "cross sign"0(conventional MRI normal) and the normal group using the FA map、directional color-coded map and between conventional MRI in the pons and cerebellar peduncles; shown in the FA color pictures on the red fibers of the bilateral cerebellar peduncle beam distribution area than the normal control group to reduce; the directional color-coded map pons, cerebellum feet fiber is significantly reduced..Conclusion1.DTI quantitative detection can reflect the situation of brain tissue damage in patients with MSA-C and showed the most serious damage regional of the olives-pons-cerebellum, they also demonstrated changes in frontal lobe and the putamen.2.the DTI color FA maps and directional color-coded map are intuitive and display meticulously the patterns of distribution of the olivocerebellopontine white matter fiber system in MSA patients, further more they provide a better valueable morphological data for clinical and basic research.