急性缺血性脑卒中FLAIR血管高信号征的相关因素及预后分析

目的探讨大脑中动脉(middle cerebral artery,MCA)供血区急性缺血性脑卒中(acute ischemic stroke,AIS)患者液体衰减反转恢复(fluid attenuated inversion recovery,FLAIR)序列血管高信号征(vascular hyperintensity,FVH)出现的相关因素及与临床预后的关系。材料与方法回顾性分析276例(2016年9月至2019年3月)MCA区域AIS患者的临床及影像资料。分为FVH阳性组和阴性组,阳性组又依据FVH的分布情况分为3个级别。此外,阳性组血管狭窄程度3级的22例患者7 d后复查(根据MRA表现分为血管再通组和未再通组),并进行了90 d随访改良Rankin量表(modified Rankin Scale,mRS)评估(根据90 d mRS评分分为预后良好组(mRS≤2)和不良组(mRS>2)。采用χ^2检验和Fisher精确检验分析影响FVH出现及级别的因素。血管再通组和未再通组之间FVH消失的情况及预后良好组和不良组的基线FVH级别、治疗后FVH消失、血管再通情况采用Fisher精确检验。预后良好组和不良组基线NIHSS评分采用t检验。结果FVH阳性组和阴性组两组之间患者年龄、性别、卒中危险因素及Willis环类型差异无统计学意义。出现症状-MRI检查时间、血管狭窄部位、程度及梗死面积差异具有统计学意义(P值分别为0.011、0.011、0.000、0.000)。阳性组不同级别间仅梗死面积差异具有统计学意义(χ^2=7.026,P=0.030)。复查血管再通组和未再通组之间FVH的消失情况差异具有统计学意义(P=0.000)。预后良好组和不良组之间基线NIHSS评分及治疗后FVH消失情况差异有统计学意义(P=0.000,P=0.002),基线FVH级别及治疗后血管再通情况差异无统计学意义(P=0.290,P=0.080)。结论患者症状-MRI检查时间、血管狭窄部位及程度、梗死面积是影响FVH出现的重要因素。治疗后FVH的消失可以预测闭塞血管再通,且患者预后与基线NIHSS评分、治疗后FVH消失情况有关,基线NIHSS评分低、治疗后FVH消失提示预后良好。     

FLAIR血管高信号与脑梗死相关性研究进展

磁共振成像是诊断急性脑梗死的重要工具,各种影像征象的研究具有重要的临床意义.液体衰减反转恢复序列血管高信号(FLAIR vascular hyperintensity,FVH)是一种在急性脑梗死患者中发现的与局部血流动力学紊乱相关的脑血管征象,此时血管在FLAIR序列上的流空效应消失,表现为高信号.近年对FVH与脑梗死...     

FLAIR序列在颅脑MR成像中的技术探讨

目的：探讨液体衰减反转恢复序列在颅脑MRI上的技术及临床应用。材料与方法：对40例脑部受检查者分别使用FLAIR序列及常规自旋回波（SE）序列进行对比分析。结果：FLAIR序列检出病灶128例,常规自旋回波序列检出病灶86个,前者比后者敏感性高,结论：FLAIR技术对颅脑病变的显示优于SE序列T2加权像,可作为颅脑MR检查常规序列的重要补充。     

FLAIR序列在颅脑疾病诊断中的应用

目的探讨液体衰减反转恢复（FLAIR）序列在颅脑疾病诊断中的应用价值。方法对64例颅脑疾病患者同时进行FLAIR及自旋回波序列检查，对其对病变的显示情况进行对比分析。结果FLAIR序列显示病灶82处，FSE序列显示54处，前者敏感性及对比度均高于后者。结论FLAIR序列对病变的显示优于自旋回波序列，特别是对大脑表面及脑室周围等处病灶的显示，FLAIR序列更具优势，临床价值更高。     

大脑中动脉闭塞致缺血性脑卒中患者FVH-DWI匹配性与预后的相关性分析

目的探讨缺血性脑卒中患者液体衰减反转恢复(fluid-attenuated inversion recovery,FLAIR)序列远端血管高信号(FLAIR vascular hyperintensity,FVH)与扩散加权成像(diffusion weighted imaging,DWI)梗死灶之间匹配性是否可以判断患者临床预后情况。材料与方法对34例大脑中动脉闭塞的缺血性脑卒中患者行常规颅脑MRI、磁共振血管造影(magnetic resonance angiography,MRA)和DWI扫描,依据FVH和DWI之间的关系分为FVH-DWI匹配组和FVH-DWI不匹配组,并随访患者进行了90 d改良Rankin量表(mRS)评估。结果FVH-DWI匹配和FVH-DWI不匹配两组患者在90 d mRS评分及90 d mRS≤2(预后良好)的差异均无统计学意义(P>0.05)。结论FVH-DWI是否匹配不能预测缺血性脑卒中患者90 d临床预后结果。     

增强FLAIR的研究进展

磁共振对比增强液体衰减反转恢复序列由于对低浓度对比剂更敏感、血管结构无强化等优势，在脑膜病变、脑肿瘤和脑缺血等疾病的诊断中具有一定的的价值，本文就增强FLAIR的基本原理和临床应用作一综述。     

MR扩散加权成像信号特征在急性缺血性脑卒中中的应用研究

目的:研究急性单发脑梗死患者首次磁共振扩散加权成像(DWI)病灶信号强度在急性脑梗死分期中的应用价值,并探讨病灶信号均质度对评估患者入院病情严重程度的价值。方法:回顾性对符合入选条件的177例前循环急性脑梗死患者,通过测得整体病灶相对信号强度(relative signal intensity, rSI)作为观察指标,统计分析超急性期、急性期和亚急性早期3组之间病灶rSI是否存在差异性;分析患者总体症状发作与首次急诊入院DWI检查的间隔时间与相应rSI的相关性;采用联合rSI的综合评分法对病灶均质与非均质进行评定,把病灶信号均质组与非均质组相应的入院NIHSS评分高低四组总体分布进行比较,并进行统计学分析。结果:177例中超急性期组24例、急性期组78例及亚急性早期组75例;轻度卒中组90例、中度卒中组66例、中-重度卒中组14例及重度卒中组7例。超急性脑梗死组rSI(1.573±0.238)、急性脑梗死组rSI(1.751±0.227)及亚急性早期脑梗死组rSI(1.943±0.309),三者相互之间均有统计学差异,所有P<0.01;177例rSI与相应的症状发作与首次急诊入院...     

磁共振DWI和FLAIR序列对判断脑梗塞期龄的作用

目的：评价DWI和FLAIR序列在脑梗塞后不同时期内的应用价值。方法：通过对65例不同发病时间脑梗塞的连续追踪的MRI－DWI和FLAIR序列扫描，分析病灶的异常信号出现的时间、范围、信号强度的差异。结果：超急性期DWI序列病灶出现明显的高信号改变，而FLAIR序列未能显示；急性期DWI序列和FLAIR序列均能显示病灶的高信号，但以DWI序列更佳；亚急性期DWI的高信号在后半程开始下降，而FLAIR像则对病灶显示得很好；慢性早期DWI信号降至等信号，FLAIR像信号开始下降，至慢性后期（30d后）大部分病灶信号降至正常，其中部分病灶降至低信号。结论：在脑梗塞发病的超急性期应常规使用DWI序列扫描，才能准确而全面地反映病灶的范围；FLAIR序列对于急性期以后的脑梗塞病灶能清楚显示其变化过程，对于多发性脑梗塞可以鉴别不同病灶的新旧程度。     

低场MRI快速FLAIR序列在颅脑中的应用

目的探讨低场MRI快速液体衰减反转恢复（fluid attenuated inversion recovery，FLAIR）序列在脑部疾病中的应用价值。方法对185例脑部疾病患者同时行常规MR T2加权像及快速FLAIR检查，比较两种序列对病灶的显示情况。结果FLAIR共检出病灶1889个，常规T2加权像检出1343个，FLAIR显示病灶的轮廓更为清晰，病灶与正常脑组织的对比度更高，在显示脑皮层下、脑室旁病灶方面更有优势，可显示常规MRT：加权像未能显示的侧裂池及脑表面脑沟的小出血病灶，在诊断颅脑外伤及蛛网膜下腔出血方面具有明显的优势。结论快速FLAIR可作为颅脑MR检查常规序列的补充。对于颅脑大部分疾病应行FLAIR检查，以提高病变的检出率，扩大MRI检查范围，减少漏诊发生。     

Application of MAGnetic resonance imaging compilation in acute ischemic stroke

BACKGROUNDSynthetic magnetic resonance imaging (MRI) MAGnetic resonance imaging compilation (MAGiC) is a new MRI technology. Conventional T1, T2, T2-fluid-attenuated inversion recovery (FLAIR) contrast images, quantitative images of T1 and T2 mapping, and MAGiC phase sensitive inversion recovery (PSIR) Vessel cerebrovascular images can be obtained simultaneously through post-processing at the same time after completing a scan. In recent years, studies have reported that MAGiC can be applied to patients with acute ischemic stroke. We hypothesized that the synthetic MRI vascular screening scheme can evaluate the degree of cerebral artery stenosis in patients with acute ischemic stroke.AIMTo explore the application value of vascular images obtained by synthetic MRI in diagnosing acute ischemic stroke.METHODSA total of 64 patients with acute ischemic stroke were selected and examined by MRI in the current retrospective cohort study. The scanning sequences included traditional T1, T2, and T2-FLAIR, three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA), diffusion-weighted imaging (DWI), and synthetic MRI. Conventional contrast images (T1, T2, and T2-FLAIR) and intracranial vessel images (MAGiC PSIR Vessel] were automatically reconstructed using synthetic MRI raw data. The contrast-to-noise ratio (CNR) values of traditional T1, T2, and T2-FLAIR images and MAGiC reconstructed T1, T2, and T2-FLAIR images in DWI diffusion restriction areas were measured and compared. MAGiC PSIR Vessel and TOF MRA images were used to measure and calculate the stenosis degree of bilateral middle cerebral artery stenosis areas. The consistency of MAGiC PSIR Vessel and TOF MRA in displaying the degree of vascular stenosis with computed tomography angiography (CTA) was compared.RESULTSAmong the 64 patients with acute ischemic stroke, 79 vascular stenosis areas showed that the correlation between MAGiC PSIR Vessel and CTA (r = 0.90, P < 0.01) was higher than that between TOF MRA and CTA (r = 0.84, P < 0.01). With a degree of vascular stenosis > 50% assessed by CTA as a reference, the area under the receiver operating characteristic (ROC) curve of MAGiC PSIR Vessel [area under the curve (AUC) = 0.906, P < 0.01] was higher than that of TOF MRA (AUC = 0.790, P < 0.01). Among the 64 patients with acute ischemic stroke, 39 were scanned for traditional T1, T2, and T2-FLAIR images and MAGiC images simultaneously, and CNR values in DWI diffusion restriction areas were measured, which were: Traditional T2 = 21.2, traditional T1 = -6.7, and traditional T2-FLAIR = 11.9; and MAGiC T2 = 7.1, MAGiC T1 = -3.9, and MAGiC T2-FLAIR = 4.5.CONCLUSIONThe synthetic MRI vascular screening scheme for patients with acute ischemic stroke can accurately evaluate the degree of bilateral middle cerebral artery stenosis, which is of great significance to early thrombolytic interventional therapy and improving patients’ quality of life.     

磁敏感加权成像对脑梗死的诊断价值

目的探讨磁敏感加权成像(SWI)对脑梗死的诊断价值。材料与方法30例患者在3.0 T MR成像系统行常规MRI、扩散加权成像(DWI)和SWI,20例同时行MR血管成像(MRA),19例行静脉注射Gd-DTPA增强扫描。将SWI采集的原始数据传输到GE AW4.4工作站离线处理,得到校正相位图(CPI)和磁化率加权图。手动测量脑梗死区及水肿区与正常对照区的CP值,采用t检验进行比较,以P0.05为差异有统计学意义。结果 30例脑梗死在DWI上表现为高信号,15例MRA图像可见大脑前、中、后动脉不同程度的狭窄或闭塞。5例SWI上可见大脑中动脉内血栓,与MRA图像显示的区域相一致;21例SWI上病灶内合并出血,CT发现9例,T1WI仅发现2例;SWI显示15例梗死区静脉血管增多,6例静脉血管分布正常,9例静脉血管分布减少。梗死区与正常对照区的CP值分别为-0.021±0.006、-0.006±0.005,差异有统计学意义(t=-2.359,P0.05);水肿区与正常对照区的CP值分别为-4.853±0.005、-1.868±0.003,差异有统计学意义(t=-2.172,P0.05)。结论 SWI对脑梗死急性期并发的出血及静脉血管分布的显示具有常规MRI无可替代的优势,对脑梗死急性期治疗具有重要的指导作用;并且校正相位图可以进行定量分析。     

Susceptibility-diffusion mismatch correlated with leptomeningeal collateralization in large vessel occlusion stroke

ObjectiveTo investigate the relationship between asymmetric prominent hypointense vessels (prominent vessel sign, PVS) on susceptibility-weighted imaging (SWI) and leptomeningeal collateralization in patients with acute ischemic stroke due to large vessel occlusion.MethodsWe retrospectively enrolled patients with M1 segment occlusion of the middle cerebral artery who underwent emergency magnetic resonance imaging and digital subtraction angiography within 24 hours from stroke onset. The extent of PVS on SWI was assessed using the Alberta Stroke Program Early CT Score (ASPECTS). Leptomeningeal collateralization on digital subtraction angiography images was assessed using the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) scale. Spearman’s rank correlation test was performed to explore the correlation of ASITN/SIR scores with SWI-ASPECTS and SWI-diffusion-weighted imaging (DWI) mismatch scores.ResultsThirty-five patients were enrolled. There was no significant correlation between SWI-ASPECTS and ASITN/SIR scores. However, SWI-DWI mismatch scores were positively correlated with ASITN/SIR scores.ConclusionThe range of PVS on SWI did not closely reflect the collateral status, while the range of SWI-DWI mismatch was significantly correlated with the leptomeningeal collateralization. In patients with acute anterior circulation stroke due to large vessel occlusion, larger SWI-DWI mismatch was associated with better leptomeningeal collaterals.     

磁共振弥散加权成像在胃癌诊断中的应用价值

目的探讨1.5T磁共振弥散加权成像在胃癌诊断中的应用价值。方法 36例胃部病变患者,其中胃癌分化好组11例,胃癌分化差组19例,良性病变组6例,同期健康成人志愿者10名为对照组,4组均行磁共振弥散加权成像,采用自旋回波/平面回波序列,测量胃壁在表观弥散系数(apparent diffusion coefficient,ADC)图上的ADC值,并进行比较。结果4组胃壁ADC值比较差异有统计学意义(F=26.76,P<0.05);根据ROC曲线,以ADC值<1.36×10-3 mm2/s为标准,磁共振弥散加权成像诊断胃癌的敏感性为87.5%,特异性为90.0%。结论磁共振弥散加权成像对进展期胃癌有较高敏感性和特异性,ADC值有助于病变的诊断和鉴别诊断。     

高分辨率MR管壁成像评估缺血性脑卒中患者血管斑块稳定性

目的 分析高分辨率MR管壁成像（HR-VWI）评估不同亚型缺血性脑卒中患者血管斑块稳定性的价值。方法 回顾性分析43例临床诊断缺血性脑卒中患者的MR HR-VWI资料,包括15例载体动脉（斑块或血栓）阻塞穿支（PAOPA）（PAOPA组）,22例动脉到动脉栓塞（ATAE）（ATAE组）,3例低灌注/栓子清除下降（HP/IEC）及3例混合机制（MM）。比较PAOPA组与ATAE组责任斑块形态、分布、位置及管腔表现的差异。结果 PAOPA组与ATAE组间责任斑块分布差异无统计学意义（χ²=12.16,P>0.05）。ATAE组责任斑块表面不规则发生率（63.64%）及斑块负荷[（70.39±11.27）%]均高于PAOPA组[26.67%,（63.11±10.57）%,χ²=8.87,t=4.02,P=0.04、0.03]。ATAE组斑块2级强化发生率（81.82%）高于PAOPA组（26.67%,χ²=7.51,P=0.03）,斑块0级强化发生率（9.09%）低于PAOPA组（46.67%,χ²=8.02,P=0.03）;2组斑块偏心性分布发生率、斑块内T1高信号发生率、斑块厚度、责任斑块处管腔狭窄率及血管重构方式差异均无统计学意义（P均>0.05）。结论 HR-VWI对鉴别不同亚型缺血性脑卒中血管斑块的稳定性具有一定价值;相比PAOPA,ATAE斑块HR-VWI更多表现出不稳定特征。