磁敏感加权成像静脉不对称性在急性缺血性脑卒中静脉溶栓中的应用
发布时间：2018-08-26 13:06
【摘要】：研究背景 缺血性卒中是我国卒中的主要亚型,约占80%。重组组织型纤溶酶原激活剂(recombinant tissue plasminogen activator, rtPA)溶栓治疗是目前临床指南推荐的有效的缺血性卒中急性期治疗之一。溶栓的目标是恢复缺血组织的灌注,那些因为处于缺血状态而失去功能,但尚未器质性死亡的神经细胞可以在血运重建后获得拯救,这些“功能受损但无器质性死亡”的组织即可被挽救的半暗带组织。 目前临床上可使用影像技术来反映卒中的生理病理变化过程,研究较多的主要是正电子发射断层显像(Positron Emission Tomography, PET)及核磁共振成像(Magnetic Resonance Imaging, MRI).PET是目前临床上用来评估半暗带的金标准,它使用各种代谢参数和配体成像技术来评估半暗带和核心梗死组织,但PET在临床无法普及。MRI利用灌注加权成像(Perfusion-Weighted Imaging, PWI)序列和弥散加权成像(Diffusion-Weighted Imaging, DWI)序列病灶的差异来表示半暗带,但PWI定义的灌注缺损尚缺乏一个良好验证且广泛认可的阈值。 近来,基于血氧水平依赖(BOLD)成像原理的磁敏感加权成像(Susceptibility-Weighted Imaging, SWI)引起研究者的兴趣。磁敏感成像对血管内脱氧血红蛋白(deoxygenated hemoglobin, DHB)敏感,而缺血组织的DHB与正常组织的DHB含量有差异,因而可作为间接反映组织氧代谢的指标。本文旨在研究SWI上脑静脉异常低信号在急性脑梗死静脉溶栓中的应用及机制。 第一部分磁敏感加权成像静脉不对称性程度与灌注缺损相关 目的：假设磁共振磁敏感成像(Susceptibility-Weighted Imaging, SWI)(3.0T)上静脉低信号不对称性可以反映缺血性脑卒中灌注缺损体积大小。 方法：我们对前瞻性登记的静脉溶栓数据库进行回顾,纳入静脉溶栓前行多模式MRI检查的前循环脑梗死患者。灌注缺损体积定义为Tmax6s的体积,静脉不对称指数(Asymmetry index, AI)定义为梗死侧与正常侧脑静脉像素和之比。溶栓前后深部静脉AI的绝对变化(AAI)定义为基线AI与24小时AI之差,相对变化(r△AI)定义为基线AI与24小时AI之比。我们使用ASPECTS评分和AI测量法两种不同的评估静脉不对称的方法,分别按数值大小分为两组,然后比较不同组之间的基线参数和预后参数。并进一步用非参数检验比较了静脉不对称性在溶栓后的变化。 结果：低ASPECTS组相较于高ASPECTS组,TIMI (thrombosis in myocardial infarction flow grading)分级更低(I士1vs2±1,P0.001),灌注缺损体积更大(105±62vs57±89ml, P=0.015),灌注缺损体积更大(104±62ml vs60±87ml, P=0.025).相较于低AI组,高AI组有更低的TIMI评分(1(IQR:0-1) vs2(IQR:0-3), P=0.002),更大的低灌注体积(120±83ml vs58±67ml, P=0.004).再通患者较无再通患者AI变化更大(△AI:1.20vs0.11, P0.001; r△AI:3.54vs1.11, P0.001);再灌注患者较无再灌患者AI变化亦更大(△AI:0.93vs0.12, P=0.031; rAAI:2.06vs1.17, P=0.029)。 结论：SWI静脉不对称可反映急性缺血性脑卒中患者的灌注缺损体积,静脉不对称性低信号可在血流再灌注后逆转。 第二部分SWI-DWI不匹配对静脉溶栓疗效的预测作用 背景和方法：磁敏感加权成像(susceptibility-weighted imaging, SWI)上的脑静脉不对称性可间接反映脑组织缺氧情况。因而我们在本研究中探讨SWI上静脉不对称明显而弥散加权成像(diffusion-weighted imaging, DWI)上病灶较小的SWI-DWI不匹配,是否能预测静脉溶栓疗效。 方法：我们对前瞻性登记的静脉溶栓数据库进行回顾,纳入静脉溶栓前行多模式MRI检查的前循环脑梗死患者。静脉不对称指数(Asymmetry index, AI)定义为梗死侧与正常侧脑静脉像素和之比,SWI-DWI不匹配定义为AI≥1.75但DWI病灶体积≤25ml。良好结局为3月改良Rankin评分(modified Rankin Scale, mRS)0-2分,单因素和多因素分析SWI-DWI不匹配是否为良好预后的独立影响因子。 结果：纳入54例患者,存在SWI-DWI不匹配的患者较无SWI-DWI不匹配的患者良好预后的比例更高(78%vs44%；OR=6.317；95%CI：1.12-35.80,P=0.037)。存在SWI-DWI不匹配的患者更能从再灌注(91%vs43%,p=-0.033)、再通(100%vs40%,P=0.013)中获得良好预后。SWI-DWI不匹配预测良好预后的准确度较灌注加权成像-弥散加权成像不匹配高(63%vs48.1%)。 结论：SWI-DWI不匹配可预测静脉溶栓疗效,可能用于筛选静脉溶栓获益患者。
[Abstract]:Research background
Thrombolytic therapy with recombinant tissue plasminogen activator (rtPA) is one of the effective therapies recommended by clinical guidelines for acute ischemic stroke. The goal of thrombolysis is to restore the perfusion of ischemic tissue, which is due to ischemia. Neurons that are in a state of disfunction but not yet organically dead can be rescued after revascularization, and these "functionally impaired but non-organically dead" tissues can be rescued in the penumbra.
At present, imaging technology can be used to reflect the physiological and pathological changes of stroke. Positron emission tomography (PET) and magnetic resonance imaging (MRI) are the main research methods. PET is the gold standard used to evaluate the penumbra in clinic. It uses various metabolic parameters. Number and ligand imaging techniques are used to assess the penumbra and core infarct tissues, but PET is not widely used in clinic. MRI uses the difference of lesions between Perfusion-Weighted Imaging (PWI) and Diffusion-Weighted Imaging (DWI) sequences to represent the penumbra, but the perfusion defect defined by PWI lacks a good one. Well validated and widely recognized threshold.
Recently, magnetic susceptibility-weighted imaging (SWI) based on the principle of blood oxygen level dependence (BOLD) has attracted researchers'interest. Magnetic susceptibility imaging (MSI) is sensitive to deoxygenated hemoglobin (DHB) in blood vessels, and DHB content in ischemic tissue is different from that in normal tissue, so it can be used as an indirect method. The purpose of this study was to investigate the application and mechanism of abnormally low signal intensity of cerebral vein on SWI in intravenous thrombolysis of acute cerebral infarction.
Part one: the degree of venous asymmetry in susceptibility weighted imaging is related to perfusion defects.
AIM: To hypothesize that low signal asymmetry in the superior vein of magnetic resonance imaging (SWI) (3.0T) can reflect the size of perfusion defect in ischemic stroke.
Methods: We retrospectively reviewed prospectively registered intravenous thrombolysis databases and included patients with anterior circulation cerebral infarction who underwent multimodal MRI before and after intravenous thrombolysis. The absolute change of intravenous AI (AAI) was defined as the difference between baseline AI and 24-hour AI, and the relative change (r Delta AI) was defined as the ratio of baseline AI to 24-hour AI. The changes of venous asymmetry after thrombolysis were compared with nonparametric tests.
Results: The TIMI (thrombosis in myocardial infarction flow grading) was lower in low ASPECTS group than in high ASPECTS group (I 6550 1) VS2 (IQR: 0-3), P = 0.002, P = 0.002, larger low perfusion volume (120 (+ 83 ml vs 58 (+ 67 ml, P = 0.004). The AI changes in patients with recanalization were greater than those without recanalization (delAI: 1.20 vs 0.11, P 0.001; R (delAI: 1.20 vs 0.11, 0.11, P 0.001; R delAI: 3.54vs 1.11, P 0.11, P 0.001); the AIchanges in reperpatients were also greater (delAI: 0.93 AI: 0.93 vs 0.12, vs 0.12, P = 0.12, v = 0.031; AArI: 2.06vs 1.06vs 1.2.B: Yes, it is.
Conclusion: SWI venous asymmetry can reflect the volume of perfusion defect in patients with acute ischemic stroke, and venous asymmetry can be reversed after reperfusion.
The second part is the predictive effect of SWI-DWI mismatch on the efficacy of intravenous thrombolysis.
BACKGROUND AND METHODS: Cerebral venous asymmetry on magnetic susceptibility-weighted imaging (SWI) indirectly reflects cerebral hypoxia. In this study, we investigated whether SWI-DWI with obvious superior venous asymmetry and small lesions on DWI did not match with SWI-DWI. To predict the efficacy of intravenous thrombolysis.
Methods: We retrospectively reviewed prospectively registered intravenous thrombolysis databases and included patients with anterior circulation cerebral infarction who underwent multimodal MRI before intravenous thrombolysis. Good outcomes were 0-2 points for modified Rankin Scale (mRS) at 3 months. Single and multivariate analysis showed that SWI-DWI mismatch was an independent predictor of good outcomes.
Results: 54 patients with SWI-DWI mismatch had a higher proportion of good prognosis than those without SWI-DWI mismatch (78% vs 44%; OR = 6.317; 95% CI: 1.12-35.80, P = 0.037). Patients with SWI-DWI mismatch had better prognosis from reperfusion (91% vs 43%, P = - 0.033), recanalization (100% vs 40%, P = 0.013). The accuracy of predicting good prognosis was higher than that of perfusion weighted imaging diffusion-weighted imaging (63%vs48.1%).
Conclusion: SWI-DWI mismatch can predict the efficacy of intravenous thrombolysis, and may be used to screen patients who benefit from intravenous thrombolysis.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R743.3
本文编号：2204952
[Abstract]:Research background
Thrombolytic therapy with recombinant tissue plasminogen activator (rtPA) is one of the effective therapies recommended by clinical guidelines for acute ischemic stroke. The goal of thrombolysis is to restore the perfusion of ischemic tissue, which is due to ischemia. Neurons that are in a state of disfunction but not yet organically dead can be rescued after revascularization, and these "functionally impaired but non-organically dead" tissues can be rescued in the penumbra.
At present, imaging technology can be used to reflect the physiological and pathological changes of stroke. Positron emission tomography (PET) and magnetic resonance imaging (MRI) are the main research methods. PET is the gold standard used to evaluate the penumbra in clinic. It uses various metabolic parameters. Number and ligand imaging techniques are used to assess the penumbra and core infarct tissues, but PET is not widely used in clinic. MRI uses the difference of lesions between Perfusion-Weighted Imaging (PWI) and Diffusion-Weighted Imaging (DWI) sequences to represent the penumbra, but the perfusion defect defined by PWI lacks a good one. Well validated and widely recognized threshold.
Recently, magnetic susceptibility-weighted imaging (SWI) based on the principle of blood oxygen level dependence (BOLD) has attracted researchers'interest. Magnetic susceptibility imaging (MSI) is sensitive to deoxygenated hemoglobin (DHB) in blood vessels, and DHB content in ischemic tissue is different from that in normal tissue, so it can be used as an indirect method. The purpose of this study was to investigate the application and mechanism of abnormally low signal intensity of cerebral vein on SWI in intravenous thrombolysis of acute cerebral infarction.
Part one: the degree of venous asymmetry in susceptibility weighted imaging is related to perfusion defects.
AIM: To hypothesize that low signal asymmetry in the superior vein of magnetic resonance imaging (SWI) (3.0T) can reflect the size of perfusion defect in ischemic stroke.
Methods: We retrospectively reviewed prospectively registered intravenous thrombolysis databases and included patients with anterior circulation cerebral infarction who underwent multimodal MRI before and after intravenous thrombolysis. The absolute change of intravenous AI (AAI) was defined as the difference between baseline AI and 24-hour AI, and the relative change (r Delta AI) was defined as the ratio of baseline AI to 24-hour AI. The changes of venous asymmetry after thrombolysis were compared with nonparametric tests.
Results: The TIMI (thrombosis in myocardial infarction flow grading) was lower in low ASPECTS group than in high ASPECTS group (I 6550 1) VS2 (IQR: 0-3), P = 0.002, P = 0.002, larger low perfusion volume (120 (+ 83 ml vs 58 (+ 67 ml, P = 0.004). The AI changes in patients with recanalization were greater than those without recanalization (delAI: 1.20 vs 0.11, P 0.001; R (delAI: 1.20 vs 0.11, 0.11, P 0.001; R delAI: 3.54vs 1.11, P 0.11, P 0.001); the AIchanges in reperpatients were also greater (delAI: 0.93 AI: 0.93 vs 0.12, vs 0.12, P = 0.12, v = 0.031; AArI: 2.06vs 1.06vs 1.2.B: Yes, it is.
Conclusion: SWI venous asymmetry can reflect the volume of perfusion defect in patients with acute ischemic stroke, and venous asymmetry can be reversed after reperfusion.
The second part is the predictive effect of SWI-DWI mismatch on the efficacy of intravenous thrombolysis.
BACKGROUND AND METHODS: Cerebral venous asymmetry on magnetic susceptibility-weighted imaging (SWI) indirectly reflects cerebral hypoxia. In this study, we investigated whether SWI-DWI with obvious superior venous asymmetry and small lesions on DWI did not match with SWI-DWI. To predict the efficacy of intravenous thrombolysis.
Methods: We retrospectively reviewed prospectively registered intravenous thrombolysis databases and included patients with anterior circulation cerebral infarction who underwent multimodal MRI before intravenous thrombolysis. Good outcomes were 0-2 points for modified Rankin Scale (mRS) at 3 months. Single and multivariate analysis showed that SWI-DWI mismatch was an independent predictor of good outcomes.
Results: 54 patients with SWI-DWI mismatch had a higher proportion of good prognosis than those without SWI-DWI mismatch (78% vs 44%; OR = 6.317; 95% CI: 1.12-35.80, P = 0.037). Patients with SWI-DWI mismatch had better prognosis from reperfusion (91% vs 43%, P = - 0.033), recanalization (100% vs 40%, P = 0.013). The accuracy of predicting good prognosis was higher than that of perfusion weighted imaging diffusion-weighted imaging (63%vs48.1%).
Conclusion: SWI-DWI mismatch can predict the efficacy of intravenous thrombolysis, and may be used to screen patients who benefit from intravenous thrombolysis.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R743.3
【参考文献】
相关期刊论文 前1条
1 Ulf Jensen-Kondering;Ruwen B銉hm;;Asymmetrically hypointense veins on T2~*w imaging and susceptibility-weighted imaging in ischemic stroke[J];World Journal of Radiology;2013年04期
，本文编号：2204952
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