~1H-MRS在蛛网膜下腔出血性脑血管痉挛发生时的评价作用

Evaluation of cerebral vasospasm resulting from subarachnoid hemorrhage with ~1H-magnetic resonance spectroscopy

目的探讨活体质子磁共振波谱(1H-MRS)在蛛网膜下腔出血(SAH)性脑血管痉挛发生时的评价作用。方法采用两次注血法建立狗SAH模型,实验分为注射生理盐水组和注血组。于模型制作成功后3、7、14d分别进行1H-MRS检查扫描,记录胆碱(Cho)、N-乙酰基天冬氨酸(NAA)和肌酸(Cr)的变化。1H-MRS扫描后即刻进行脑血管造影检查,测定基底动脉血管痉挛发生情况,与1H-MRS扫描结果加以比较分析。结果脑血管造影结果提示在第3天基底动脉血管发生明显痉挛,到第7天各段血管痉挛最为显著,第14天血管痉挛明显改善;1H-MRS的检测指标显示注血组各项指标在第3、7天变化较大,其中NAA在第3天下降到低谷,之后逐渐回升,至第14天接近正常水平;Cho在第3天稍有下降,然后上升,至第7天上升至高峰,尔后下降;而Cr则一直表现为上升趋势,但第7天后上升趋势明显放缓,与第14天相对含量相比差异无显著性(P>0.05)。1H-MRS功能检测结果与脑血管造影结果具有一定的吻合性。结论1H-MRS可用来监测蛛网膜下腔出血性脑血管痉挛发生时病程进展,是一种较好的功能影像学评价手段。

Objective To assess the value of ^1H-magnetic resonance spectroscopy （tH-MRS） in evaluating cerebral vasospasm resulting from subaraehnoid hemorrhage （SAIl）. Methods Six dogs were subjected to autologous non-heparinized blood injection via eisternal puncture twice at one-day interval to establish models of SAH, and another 6 received injections with normal saline in an identical manner, ^1H-MRS scan was performed on the 3rd, 7th and 14th days aider the injections to measure the changes of N-aeetylaspartate （NAA）, ereatine （Cr） and choline （Cho）. After the ^1H-MRS scan, all the dogs underwent brain digital subtraction angiography （DSA） for determining the basilar artery diameter, Results DSA results on day 3 presented development of obvious vasospasm of the basilar artery, which was most evident on day 7 and recovered obviously on day 14. ^1H-MRS results demonstrated obvious changes ofNAA, Cho and Cr on days 3 and 7 in SAH model group, and NAA declined to the lowest level on day 3 followed by gradual ascending till reaching the normal level on day 14. Cho d^creased slightly on day 3, then increased and reached the peak level on day 7 and then decreased. Cr rose steadily from day 3 to 14, but since day 7, the rise slowed down obviously and Cr maintain a level not significantly different from that on day 14 （P〉0.05）. The functional results of ^1H-MRS were consistent with the DSA results. Conclusion ^1H-MRS can be used to monitor the development of cerebral vasospasm resulting from SAH as a good evaluation method for functional imaging.