二维多体素波谱定量分析遗忘型轻度认知功能障碍患者颅内代谢物

目的 利用二维多体素波谱(2D-CSI)技术定量分析及评估遗忘型轻度认知功能障碍患者(aMCI)的颅内代谢物.方法 利用1.5T MR扫描仪对19例aMCI患者(aMCI组)及21名正常对照者(对照组)行CSI扫描,对所得数据用LCModle联合SAGE 7.0软件进行后处理,在双侧扣带回后部(PCG)、双侧楔前叶(Pr)、双侧侧脑室后角旁白质区(PWM)、双侧背侧丘脑(DT)及双侧豆状核(LN)选取体素,比较两组N-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)、肌醇(MI)的绝对浓度及NAA/Cr、Cho/Cr、MI/Cr及NAA/MI比值.结果 aMCI组NAA浓度于双侧PCG、双侧PWM及左侧Pr较对照组降低(P均＜0.05)；右侧PCG MI浓度及左侧PWM Cho浓度较对照组升高(P＜0.05)；两组间Cr浓度差异无统计学意义(P＞0.05)；NAA/Cr于左侧PCG、左侧DT及右侧PWM较对照组降低(P均＜0.05)；NAA/MI于双侧PCG、双侧PWM及左侧DT较对照组有不同程度降低(P均＜0.05);两组间MI/Cr、Cho/Cr差异均无统计学意义(P＞0 05).结论 2D-CSI技术能够检测aMCI患者颅内不同区域代谢物的变化,为临床评估提供有效的生化信息.

Quantitative analysis of brain metabolites in patients with amnestic mild cognitive impairment by using 2D-multi-voxel spectroscopy

Objective To quantitatively analyze and evaluate the changes of brain metabolites in patients with amnestic mild cognitive impairment (aMCI) by 2D-multi-voxel spectroscopy (2D-chemical shift imaging, 2D-CSI). Methods Nineteen aMCI patients (aMCI group) and 21 normal control subjects (control group) were enrolled to receive CSI scanning by 1.5T MRI. The data were post-processed by using LCModel and SAGE 7.0 software. Voxels were selected bilaterally in posterior cingulate gyrus (PCG), precuneus (Pr), posterior horn of the lateral ventricle paratrigonal white matter (PWM), dorsal thalamus (DT) and lentiform nucleus (LN). The absolute concentration of N-acetyl aspartate (NAA), choline (Cho), creatine (Cr), myo-inositol (mI) and NAA/Cr, Cho/Cr, MI/Cr and NAA/MI ratios were measured in the above sites. Results aMCI group displayed significantly lower NAA level in bilateral PCG, PWM and left Pr than the normal control subjects (all P<0.05). The concentration of MI in the right PCG and Cho in the left PWM elevated compared with those of normal control subjects (both P<0.05). No statistical difference in Cr was observed between the two groups (P>0.05). NAA/Cr decreased in the left PCG, DT, and right PWM (all P<0.05). The metabolite ratio of NAA/MI decreased in the bilateral PCG, PWM and left DT (all P<0.05). No significant change of MI/Cr and Cho/Cr ratios was observed between the two groups. Conclusion The metabolite changes of patients with aMCI can be detected by 2D-CSI, therefore providing efficient biochemical information for clinic.