Martínez-Bisbal M C, Arana E, Martí-Bonmatí L, Martínez-Granados B, Celda B
Departamento de Química-Física, Universidad de Valencia, España.
Radiologia. 2006 Sep-Oct;48(5):301-7. doi: 10.1016/s0033-8338(06)75139-6.
To analyze the diagnostic accuracy of proton magnetic resonance spectroscopy (1H MRS) in patients with cognitive impairment and to establish the usefulness of complementary information provided by conventional magnetic resonance imaging (MRI).
64 patients with cognitive impairment, including Alzheimer's disease (AD) (n=31), vascular dementia (n=6), mild cognitive impairment (MCI) (n=9), and major depression (n=18), were studied. All patients underwent cerebral MRI and single-volume 1H MRS using two echo times (TE, 31 and 136 ms) in the posterior cingulate gyrus and right temporal lobe. The metabolites analyzed were N-acetylaspartate (NAA), myo-Inositol (mI), choline (Ch), and creatine (Cr), and the ratios of Ch/Cr, mI/Cr, NAA/mI and NAA/Cr were calculated. In order to differentiate among the different types of cognitive impairment, the alterations in imaging and spectroscopy findings were graded from 0 to 4, as was the mean combination of the two, and then ROC curves were obtained.
Statistically significant differences were found between the spectra of patients with dementia (AD and vascular dementia) and those without dementia (MCI and depression) in the posterior cingulate gyrus. The NAA/mI ratio yielded the best area under the ROC curve, with the best sensitivity (82.5%) and specificity (72.7%) in the diagnosis of AD. The NAA/mI and mI/Cr quotients differentiated between the four degenerative pathologies causing the cognitive impairment. The combination of MRI and 1H MRS significantly improved the accuracy of the diagnosis of AD.
The metabolic differences found among patients with cognitive impairment using 1H MRS can be useful for differentiating AD, vascular dementia, MCI, and depression. The combination of spectroscopy and MRI findings is useful in the diagnosis of AD.
分析质子磁共振波谱（1H MRS）对认知障碍患者的诊断准确性，并确定传统磁共振成像（MRI）提供的补充信息的有用性。
研究了64例认知障碍患者，包括阿尔茨海默病（AD）（n = 31）、血管性痴呆（n = 6）、轻度认知障碍（MCI）（n = 9）和重度抑郁症（n = 18）。所有患者均接受了脑部MRI检查，并在后扣带回和右侧颞叶使用两个回波时间（TE，31和136毫秒）进行单体积1H MRS检查。分析的代谢物包括N-乙酰天门冬氨酸（NAA）、肌醇（mI）、胆碱（Ch）和肌酸（Cr），并计算Ch/Cr、mI/Cr、NAA/mI和NAA/Cr的比值。为了区分不同类型的认知障碍，将成像和波谱结果的改变从0到4进行分级，两者的平均组合也进行分级，然后获得ROC曲线。
在扣带回后部，痴呆患者（AD和血管性痴呆）与非痴呆患者（MCI和抑郁症）的波谱存在统计学显著差异。NAA/mI比值在ROC曲线下面积最大，在AD诊断中具有最佳敏感性（82.5%）和特异性（72.7%）。NAA/mI和mI/Cr商数区分了导致认知障碍的四种退行性病变。MRI和1H MRS的联合显著提高了AD诊断的准确性。
使用1H MRS在认知障碍患者中发现的代谢差异有助于区分AD、血管性痴呆、MCI和抑郁症。波谱和MRI结果的联合对AD诊断有用。
