质子磁共振波谱和MR表观扩散系数在短暂性脑缺血发作中的应用

Application of ^1H-MR spectroscopy and MR ADC in transient ischemic attack

目的:利用质子磁共振波谱(1H-MRS)技术和MR表观扩散系数(ADC)分析短暂性脑缺血发作(TIA)的脑代谢改变。方法:应用多体素1H-MRS技术和弥散加权成像分别对30例TIA患者和30例正常志愿者进行检查,测量双侧大脑半球半卵圆中心ADC值和脑内代谢物氮-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)和乳酸(Lac)的峰高比率,并作统计学分析。结果:30例病例中有11例患侧ADC值(6.31±0.87×10-4mm2/s)较对侧(7.97±0.79×10-4mm2/s)及正常对照组(8.46±0.79×10-4mm2/s)显著下降,有统计学意义差异(P<0.01)。病变侧半卵园中心NAA/Cho(1.45±0.29)、NAA/Cr(1.56±0.23)低于对侧(1.65±0.21,1.81±0.16)及正常对照组(1.62±0.18,1.80±0.12),差异有显著性意义(P<0.01);Cho/Cr(1.20±0.16)高于对侧(1.07±0.15)及正常对照组(1.05±0.11),差异有显著性意义(P<0.05);Lac/NAA(0.18±0.06)高于对侧(0.00±0.00)及正常对照组(0.00±0.00),差异有显著性意义(P<0.01)。结论:多体素1H-MRS技术可以定量反映TIA患者脑组织神经细胞的生物代谢改变,其准确性及敏感性优于ADC值,1H-MRS技术结合弥散加权成像,为TIA的诊断提供了客观的影像学依据。

Objective：Using ^1H magnetic resonance spectroscopy inmging （^1H-MRSI）and apparent diffusion coefficient（ADC） to investigate the cerebral metabolic changes in patients with transient isehemic attack（TIA）. Methods： ^1H-M1LS and diffusion weighted magnetic resonance imaging were performed in 30 patients with TIA and 30 control subjects, ADC value and cerebral metabolism were calcuhated in the centrum semiovale of both hemispheres. Cerebral metabolism was study by assessing the ratio of nitro-acetyl aspartate to choline （NAA/Cho） as well as to creatine （NAA/Cr）, and the ratio of choline to creatine （Cho/Cr）, and lactate to nitro-acetyl aspartate （Lac/NAA） in the centrum semiovale of both hemispheres.Results： Of the total 30 cases, the affected area showed ADC （6.31 ± 0.87 × 10^-4mm^2/s） reduction in 11 cases, ADC were signifieandy decreased and lower than that of non-affected hemisphere （7.97 ± 0.79 × 10^-4mm^2/s） as well as the control subjects （8.46 ± 0.79 × 10^-4mm^2/s）, With significant statistic difference （ P 〈 0.01）. In TIA patients,the NAA/Cho and NAA/Cr of the affected area （1.45 ± 0.29,1.56 ± 0.23, respectively） were signiticanfly decreased and lower than that of non-affected hemisphere （ 1.65 ± 0.21,1.81 ± 0.16, respectively）, as well as the control subjects （ 1.62 ± 0.18, 1.80 ± 0.12, respectively） with significant statistic difference（ P 〈 0.01 ） ; The Cho/Cr of the affected hemisphere （ 1.20 ± 0.16） was significandy increased and higher than that of the non-affected hemisphere （ 1.07 ± 0.15） and control subjects （ 1.05 ± 0.11 ）, with statistic difference （ P 〈 0.05） ; The Lac/NAA of the affected hemisphere （0.18 ± 0.06） was significantly increased and higher than that of the non-affected hemisphere （0.00 ± 0.00） and control subjects （0.00 ± 0.00）, with statistic difference （ P 〈 0.01）. Cortclusion：Abnormal cerebral metabohc changes in patients With TIA could be demonstrated by ^1H-MRS. The accuracy and sensitivity in ^1H-MILSI had hatter advantages than ADC value, a combination of ^1H-MILS and diffusion weighted imaging can provide objective imaging means for the diagnosis of the TIA.