^(13)N-Ammonia PET/CT脑血流灌注显像结合醋甲唑胺负荷试验对单侧大脑中动脉或颈内动脉狭窄患者脑血管储备的评定

Cerebrovascular Reserve in Patients with Unilateral Internal Carotid Artery or Middle Cerebral Artery Stenosis:Study with ^(13)N-Ammonia PET/CT Combined with Methazolamide

目的探讨^(13)N-ammonia PET/CT脑血流灌注显像结合醋甲唑胺负荷试验在缺血性脑血管病脑血管储备评定中的应用价值。方法 2014年1月~2015年12月,10名正常人和53例单侧大脑中动脉或颈内动脉狭窄患者在基态和醋甲唑胺负荷后分别行^(13)N-ammonia PET/CT脑血流灌注显像成像。在双侧额叶、顶叶、颞叶、枕叶、基底节和丘脑勾画相应的感兴趣区,计算两侧的平均放射性计数和血流变化率。结果正常人基态和负荷后,双侧额叶、顶叶、颞叶、枕叶、基底节和丘脑放射性分布均大致对称。基底节、丘脑放射性分布高于皮质,白质放射性分布最低。负荷后双侧放射性计数均较基态时增高,双侧增高幅度基本一致(t=1.552,P=0.132)。基态显像时,39例患者呈现126个血流灌注减低区。负荷后,49例患者呈现183个血流灌注减低区。基态时已有血流灌注减低区的39例患者中,16例负荷后出现新的血流灌注减低区,13例29个病灶血流灌注较基态时改善。血流灌注减低区的负荷血流变化率与基态血流变化率有显著性差异(t=2.466,P<0.05)。结论^(13)N-ammonia PET/CT脑血流灌注显像结合醋甲唑胺负荷试验能够很好评估单侧大脑中动脉或颈内动脉狭窄患者脑血管储备的变化,对缺血性脑血管病的病情评估和早期干预有重要临床意义。

Objective To evaluate the cerebrovascular reserve（CVR） with ^（13）N-ammonia PET/CT and methazolamide in patients with cerebral ischemic disease. Methods From January, 2014 to December, 2015, basal and stress PET/CT were performed in ten healthy persons and 53 patients with unilateral internal carotid artery or middle cerebral artery stenosis. Radioactive counts were measured on mirror regions of bilateral frontal lobe, parietal lobe, temporal lobe, occipital lobe, basal ganglia and thalamus to calculate the blood flow change rate. Results For the healthy persons, the radioactive distribution of bilateral frontal lobe, parietal lobe, temporal lobe, occipital lobe, basal ganglia and thalamus were roughly symmetrical on both basal and stress PET/CT. The radioactive counts were more in basal ganglia and thalamus than in cortex, and the least in white matter. The radioactive counts were more on stress PET/CT than basal PET/CT, and there was no significant difference between both sides（t=1.552, P=0.132）. For the patients, the blood flow perfusion decreased in 39 patients with 126 regions on basal PET/CT, and 49 patients with 183 regions on stress PET/CT. Within the 39 patients who found decreased blood flow perfusion regions, 16 patients were found new regions on stress PET/CT, and 29 regions of 13 patients improved in blood flow perfusion on stress PET/CT. The blood flow change rate was significantly different between basal and stress PET/CT（t=2.466, P〈0.05）. Conclusion13N-ammonia PET/CT cerebral blood flow perfusion imaging combined with methazolamide stress test can evaluate the cerebrovascular reserve in patients with unilateral internal carotid artery or middle cerebral artery stenosis, and is valuable for clinical assessment and early intervention for patients with cerebral ischemic disease.