DTI评价不同期HIV相关性痴呆脑白质微细结构损害

Preliminary study of DTI on micro-structural white matter damage in patients with HIV-1 associated dementia complex

目的:应用磁共振扩散张量成像(DTI)技术研究不同期HIV相关性痴呆(HAD)患者脑白质微细结构的改变。方法:对17例HAD患者(中重度组9例,亚临床组8例)及10例年龄性别相匹配的健康对照组行常规MRI及DTI检查,测量其额叶、顶叶、颞叶、枕叶、胼胝体膝部、压部、内囊前、后肢白质区部分各向异性分数(FA)和表观扩散系数(ADC),比较3组的FA、ADC值。结果:亚临床组HAD患者常规MRI检查正常,中重度患者T2-TIRM序列均显示不同程度的白质异常;中重度组患者额叶、顶叶、颞叶、枕叶FA值均低于正常对照组,额叶、顶叶、颞叶ADC值均高于正常对照组,有显著性差异(P<0.05);中重度组患者额叶、枕叶FA值均低于亚临床组患者,额叶、颞叶ADC值均高于亚临床组患者(P<0.05);亚临床组患者额叶、枕叶FA值均低于正常对照组,额叶、顶叶ADC值均高于正常对照组(P<0.05);胼胝体膝部、压部、内囊前后肢3组间FA值及ADC值均无显著性差异(P>0.05)。结论:对HAD患者行定量DTI分析有助于评价HAD常规MRI检查正常区域的微结构改变,并且能够评价HAD的严重程度,这有助于HAD的早期预防及治疗,阻止或逆转认知下降;不同期的HAD患者可能存在脑白质选择性微细结构损害,该损害最先出现在与高级皮层功能相关的脑区(如额叶)。

Objective：To investigate the micro-structural white matter damage in patients with HIV-1 associated de- mentia complex （HAD） using diffusion tensor imaging （DTI）. Methods： 17 patients with HAD （moderate and severe group,9 cases;sub-clinical group,8 cases） and 10 age and sex matched normal controls （NC） were recruited. Routine MRI and DTI were performed,and fractional anisotropy （FA） ,apparent diffusion coefficient （ADC） of normal-appearing white matter （NAWM） in frontal, parietal, temporal,occipital lobes, genu and splenium of the corpus callosum, and anterior and posterior limbs of the internal capsule of the above--mentioned 3 groups were measured and compared. Results： Of the rood crate and severe HAD group, the FA values in the frontal, parietal, temporal, occipital lobes were lower than that of the NC group, whereas the ADC values in the frontal, parietal, temporal lobes were higher, with significant statistical differences （all P〈0.05）. Of the moderate and severe HAD group, the FA values in frontal,occipital lobes were lower than that of the sub-clinical group, and the ADC values in the frontal, temporal lobes were higher （all P〈0.05） ;the FA values in the fron- tal,occipital lobes of sub-clinical group were lower than that of NC group,the ADC values in the frontal,parietal lobes were higher （all P^0.05）;There were no significant statistical differences in the FA values and ADC values in the genu and splenium of the corpus callosum, and anterior and posterior limbs of the internal capsule among the three groups （P~ 0.05）. Conclusions： Quantitative DTI analysis was helpful in assessing the white matter damage and in monitoring the sever- ity of cognitive impairment in HAD patients. Selective micro--structural white matter damage could be revealed in patients with different stages of HAD,the damage could be assessed firstly in the cerebral regions serving higher cortical functions （frontal, parietal lobes）;as the damage progressed, then appeared at the regions serving primary functions, which might be helpful for early 0revention and treatment of HAD natients.and the co^tnitivo cto^lln^tlnn mictht hp n toA A