3.0T磁共振ASL及MRS技术在阿尔茨海默病的应用研究

3.0T MRI arterial spin labeling and magnetic resonance spectroscopy technology in application of Alzheimer's disease

目的应用磁共振动脉自旋标记(arterial spin labeling,或arterial spin tagging,ASL)及磁共振波谱分析(magnetic resonance spectroscopy,MRS)技术,分析阿尔茨海默病(Alzheimer's disease,AD)患者脑血流灌注和扣带回后部波谱的改变情况。方法采集静息状态下20例AD患者(AD组)及20例健康志愿者(对照组)动脉自旋标记的灌注成像数据和扣带回后部的谱线,计算其相对脑血流量,比较谱线差异。结果患者双侧额叶、颞叶、颞顶交界区、顶叶皮质及海马区的脑血流量较健康对照者显著下降(均P<0.05)。与对照组比较,AD患者扣带回后部波谱的主要表现:NAA,NAA/Cr↓;Cho,Cho/Cr↑;MI,MI/Cr(>0.70,为早期异常,对诊断最重要)↑,(NAA为N-乙酰天门冬氨酸,Cho为胆碱,Cr为肌酸,MI为肌醇)。结论动脉自旋标记和磁共振波谱分析联合应用于阿尔茨海默病,不仅可以显示AD患者局部脑血流减低区,而且可以显示扣带回后部的异常代谢改变,同时能提供可靠的诊断及鉴别诊断信息。

Objective To analyze the application of arterial spin labeling （ASL） and magnetic resonance spectroscopy （MRS） technique in cerebral perfusion and posterior cingulate cortex＇s MRS of patients with Alzheimer＇s disease（AD）. Methods Cerebral perfusion imaging data of ASL and posterior eingulate cortex＇s MRS were collected from 20 AD patients （AD group） and 20 healthy volunteers（control group）. Relative cerebral blood flow （rCBF） in two groups was measured and MRS was compared, too. Results The CBF values of bilateral frontal lobe,temporal lobe,temporoparietal junction, parietal lobe and hippocampal areas were significantly decreased compared with these in control subjects （all P〈0.05）. Compared with normal group, the posterior cingulate eortex＇s MRS of patients with AD main performance was as follows： NAA, NAA/Cr ↓;Cho, Cho/Cr ↑ ; MI, MI/Cr （〉0.70, the most important data were found in early stages of AD） ↑ , （ N-acetyl asparte, NAA; choline, Cho; creatine, Cr; myo-inositol, MI）. Conclusion The method combining application of ASI. and MRS in Alzheimer＇s disease can show not only regional hypoperfusion, but also abnormal metabolism of posterior cingulate cortex,and provide valuable information in diagnosis and differential diagnosis.