Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages...Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages and is now available for routine clinical practice in many institutions.Its noninvasive nature and ability to quantitatively measure tissue perfusion make ASL ideal for research and clinical studies.Recent technical advances have increased its sensitivity and also extended its potential applications.This review focuses on some basic knowledge of ASL perfusion,emerging techniques and clinical applications in neuroimaging.展开更多
MULTIPLE sclerosis （MS） is a common inflammatory demyelinating disorder of central nervous system, and the disease burder could be well evaluated by conven-tional magnetic resonance imaging （MRI）,1 including T2-we...MULTIPLE sclerosis （MS） is a common inflammatory demyelinating disorder of central nervous system, and the disease burder could be well evaluated by conven-tional magnetic resonance imaging （MRI）,1 including T2-weighted, fluid-attenuatd inversion recovery, and postcontrast Tl-weighted sequences. 2 We investigated the perfusion state of MS plaques using brain perfusion imaging in a 12-year-old boy with MS.展开更多
Purpose: To evaluate respiratory-triggered three-dimensional (3D) true steady-state free-precession (SSFP) projection magnetic resonance angiographic sequences with time-spatial labeling inversion pulse (Time-SLIP) fo...Purpose: To evaluate respiratory-triggered three-dimensional (3D) true steady-state free-precession (SSFP) projection magnetic resonance angiographic sequences with time-spatial labeling inversion pulse (Time-SLIP) for visualizing the hepatic arteries and to optimize the image acquisition protocol. Materials and Methods: A 1.5-T clinical magnetic resonance imager was used to perform abdominal magnetic resonance angiography (MRA) in 25 consecutive patients before transcatheter arterial chemoembolization or surgery. We compared two selective space-labeling inversion pulse (tag pulse) patterns (Patterns I and II, oblique and parallel tag pulses, respectively). Two experienced radiologists evaluated the number of hepatic arterial branches visible on the acquired MRA images, and the results were referenced with those on images from intra-arterial digital subtraction angiography. Results: Images were acquired from all patients. The two radiologists clearly visualized branches of the left and right hepatic arteries. More peripheral hepatic arterial branches were identified in MRA images captured by using tag pulse Pattern I than in those acquired by using Pattern II (P P > 0.05). Conclusion: Non-contrast-enhanced Time-SLIP hepatic MRA with true SSFP allowed selective visualization of peripheral hepatic vessels.展开更多
目的测定阿尔茨海默病(AD)患者全脑3D伪连续动脉自旋标记(3D pc ASL)成像中动脉通过时间(ATT)分析其与脑血流灌注减低的相关性。方法对12例AD患者(AD组)和17例年龄匹配的认知功能正常者(对照组)进行常规MR和3D pc ASL灌注成像。使用SPM ...目的测定阿尔茨海默病(AD)患者全脑3D伪连续动脉自旋标记(3D pc ASL)成像中动脉通过时间(ATT)分析其与脑血流灌注减低的相关性。方法对12例AD患者(AD组)和17例年龄匹配的认知功能正常者(对照组)进行常规MR和3D pc ASL灌注成像。使用SPM 8软件对ATT成像图进行预处理,比较两组ATT差异,评价ATT升高脑区ATT值与CBF减低的相关性。结果 AD组ATT升高区主要见于左侧岛叶,左侧额下回,左侧颞上回及颞中回,双侧后扣带回,双侧楔前叶,左侧海马旁回(t=2.4727,P<0.001)。结论灌注减低区的ATT值与脑血流灌注减低存在相关性。展开更多
目的采用三维准连续脉冲动脉自旋标记(3D pseudocontinuous arterial spin labeling,3D p CASL)技术研究复发缓解型多发性硬化(relapsing-remitting multiple sclerosis,RRMS)患者看似正常的脑白质区(normal appearing white matter,NA...目的采用三维准连续脉冲动脉自旋标记(3D pseudocontinuous arterial spin labeling,3D p CASL)技术研究复发缓解型多发性硬化(relapsing-remitting multiple sclerosis,RRMS)患者看似正常的脑白质区(normal appearing white matter,NAWM)脑血流量(cerebral blood flow,CBF)变化,并分析其临床相关性。材料与方法本研究共纳入29例RRMS患者及年龄性别完全匹配的17名健康志愿者。所有受试者通过GE公司的3.0 T MR采集了T2加权成像(T2weighted image,T2WI)、三维快速扰相梯度回波序列(3-dimensional fast spoiled gradient echo,3D-FSPGR)及3D p CASL。将3D p CASL标准化配准后在半卵圆中心NAWM、侧脑室旁NAWM手绘感兴趣区,得到两个区域的平均CBF值。采用两独立样本t检验比较RRMS和健康志愿者的NAWM CBF值的差异,并将CBF值与临床资料进行相关性分析。结果与健康志愿者比较,RRMS患者半卵圆中心NAWM及侧脑室旁NAWM的CBF值明显降低(半卵圆中心NAWM:32.5452±4.5848 vs 35.4865±5.7968,P=0.036;侧脑室旁NAWM:30.7788±4.1746 vs 34.0530±4.4821,P=0.006)。RRMS患者半卵圆中心NAWM及侧脑室旁NAWM的CBF值与患者的年龄、发病年龄、发病次数、病程、扩展残疾状态量表(expanded disability status scale,EDSS)评分没有明显相关性。结论采用3D p CASL技术定量分析RRMS患者微循环的脑血流灌注情况发现,在常规MRI没有明显病变的NAWM的CBF值明显降低。该研究表明RRMS患者NAWM存在潜在的血流动力学改变,进一步提示血流动力学因素在RRMS患者的发病中可能起着重要的作用。展开更多
目的探讨使用时间-空间标记反转脉冲(time-spatial labeling inversion p u l s e,Ti m e-S L I P)非对比增强血管成像技术评价肾动脉的价值。材料与方法使用1.5 T MR扫描仪对36例临床怀疑肾动脉狭窄的患者行Time-SLIP磁共振血管造影术(...目的探讨使用时间-空间标记反转脉冲(time-spatial labeling inversion p u l s e,Ti m e-S L I P)非对比增强血管成像技术评价肾动脉的价值。材料与方法使用1.5 T MR扫描仪对36例临床怀疑肾动脉狭窄的患者行Time-SLIP磁共振血管造影术(magnetic resonance angiography,MRA)检查。以320排CT血管造影(computed tomography angiography,CTA)和数字减影血管造影(digital subtraction angiography,DSA)为参考标准,评价Time-SLIP肾动脉MRA的图像质量和诊断肾动脉狭窄的能力。结果共71支肾动脉纳入研究,图像质量优秀的有51支(72%),良好的有17支(24%),差的有3支(4%)。Time-SLIP MRA诊断肾动脉狭窄的敏感度、特异度分别为100%、98.2%,诊断明显狭窄(狭窄程度>50%)的敏感度、特异度分别为90%、98.4%。Time-SLIP MRA定量评估肾动脉狭窄程度与CTA和DSA呈高度相关(r=0.959,P<0.01),但Time-SLIP MRA轻度高估肾动脉的狭窄程度[平均偏倚为(3.31±10.04)%]。结论 Time-SLIP非对比增强血管成像技术能够准确评价肾动脉。展开更多
目的探讨磁共振三维动脉自旋标记脑灌注成像(3D ASL)中不同标记后延迟时间(PLD)对急性脑梗死不同脑区血流量的影响。方法随机选取基底节区新发脑梗死患者15例,采用不同标记后延迟时间(PLD=1.5s和PLD=2.5s)进行3D-ASL检查。通过GE AW 4....目的探讨磁共振三维动脉自旋标记脑灌注成像(3D ASL)中不同标记后延迟时间(PLD)对急性脑梗死不同脑区血流量的影响。方法随机选取基底节区新发脑梗死患者15例,采用不同标记后延迟时间(PLD=1.5s和PLD=2.5s)进行3D-ASL检查。通过GE AW 4.6后处理工作站,分别获得不同PLD时间点的全脑血流量(CBF)图,选取双侧额、颞、顶、枕叶、小脑和基底节区为感兴趣区,其中基底节区选取弥散加权成像(DWI)上高信号梗死区域,测量患侧和对侧镜像区域的CBF值。采用配对t检验分析不同PLD时间各脑区CBF值之间的差异,以及相同PLD的各脑区患侧和对侧CBF值之间的差异。P值小于0.05为有统计学显著差异。结果不同PLD时间点比较发现,额、颞、顶、枕叶及小脑半球区域CBF值在PLD=1.5s均低于PLD=2.5s,具有统计学显著差异(P均<0.05);基底节区域的CBF值在PLD=1.5s和PLD=2.5s无统计学显著差异。相同PLD的各脑区患侧和对侧CBF值比较发现,在PLD=1.5s或2.5s,颞、顶、枕叶及小脑半球区域患侧与对侧的CBF值均无统计学显著差异;而额叶的患侧与对侧的CBF值在PLD=1.5s有统计学显著差异(P<0.05),在PLD=2.5s无统计学显著差异;基底节区的患侧与对侧的CBF值在两种不同的延迟时间均有统计学显著差异(P均<0.05)。结论急性脑梗死患者3D ASL成像不同PLD时间对脑血流量的定量分析具有重要影响,合理选择PLD时间参数有助于准确评估急性脑梗死的全脑血流灌注情况。展开更多
文摘Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages and is now available for routine clinical practice in many institutions.Its noninvasive nature and ability to quantitatively measure tissue perfusion make ASL ideal for research and clinical studies.Recent technical advances have increased its sensitivity and also extended its potential applications.This review focuses on some basic knowledge of ASL perfusion,emerging techniques and clinical applications in neuroimaging.
文摘MULTIPLE sclerosis （MS） is a common inflammatory demyelinating disorder of central nervous system, and the disease burder could be well evaluated by conven-tional magnetic resonance imaging （MRI）,1 including T2-weighted, fluid-attenuatd inversion recovery, and postcontrast Tl-weighted sequences. 2 We investigated the perfusion state of MS plaques using brain perfusion imaging in a 12-year-old boy with MS.
文摘Purpose: To evaluate respiratory-triggered three-dimensional (3D) true steady-state free-precession (SSFP) projection magnetic resonance angiographic sequences with time-spatial labeling inversion pulse (Time-SLIP) for visualizing the hepatic arteries and to optimize the image acquisition protocol. Materials and Methods: A 1.5-T clinical magnetic resonance imager was used to perform abdominal magnetic resonance angiography (MRA) in 25 consecutive patients before transcatheter arterial chemoembolization or surgery. We compared two selective space-labeling inversion pulse (tag pulse) patterns (Patterns I and II, oblique and parallel tag pulses, respectively). Two experienced radiologists evaluated the number of hepatic arterial branches visible on the acquired MRA images, and the results were referenced with those on images from intra-arterial digital subtraction angiography. Results: Images were acquired from all patients. The two radiologists clearly visualized branches of the left and right hepatic arteries. More peripheral hepatic arterial branches were identified in MRA images captured by using tag pulse Pattern I than in those acquired by using Pattern II (P P > 0.05). Conclusion: Non-contrast-enhanced Time-SLIP hepatic MRA with true SSFP allowed selective visualization of peripheral hepatic vessels.
文摘目的测定阿尔茨海默病(AD)患者全脑3D伪连续动脉自旋标记(3D pc ASL)成像中动脉通过时间(ATT)分析其与脑血流灌注减低的相关性。方法对12例AD患者(AD组)和17例年龄匹配的认知功能正常者(对照组)进行常规MR和3D pc ASL灌注成像。使用SPM 8软件对ATT成像图进行预处理,比较两组ATT差异,评价ATT升高脑区ATT值与CBF减低的相关性。结果 AD组ATT升高区主要见于左侧岛叶,左侧额下回,左侧颞上回及颞中回,双侧后扣带回,双侧楔前叶,左侧海马旁回(t=2.4727,P<0.001)。结论灌注减低区的ATT值与脑血流灌注减低存在相关性。
文摘目的采用三维准连续脉冲动脉自旋标记(3D pseudocontinuous arterial spin labeling,3D p CASL)技术研究复发缓解型多发性硬化(relapsing-remitting multiple sclerosis,RRMS)患者看似正常的脑白质区(normal appearing white matter,NAWM)脑血流量(cerebral blood flow,CBF)变化,并分析其临床相关性。材料与方法本研究共纳入29例RRMS患者及年龄性别完全匹配的17名健康志愿者。所有受试者通过GE公司的3.0 T MR采集了T2加权成像(T2weighted image,T2WI)、三维快速扰相梯度回波序列(3-dimensional fast spoiled gradient echo,3D-FSPGR)及3D p CASL。将3D p CASL标准化配准后在半卵圆中心NAWM、侧脑室旁NAWM手绘感兴趣区,得到两个区域的平均CBF值。采用两独立样本t检验比较RRMS和健康志愿者的NAWM CBF值的差异,并将CBF值与临床资料进行相关性分析。结果与健康志愿者比较,RRMS患者半卵圆中心NAWM及侧脑室旁NAWM的CBF值明显降低(半卵圆中心NAWM:32.5452±4.5848 vs 35.4865±5.7968,P=0.036;侧脑室旁NAWM:30.7788±4.1746 vs 34.0530±4.4821,P=0.006)。RRMS患者半卵圆中心NAWM及侧脑室旁NAWM的CBF值与患者的年龄、发病年龄、发病次数、病程、扩展残疾状态量表(expanded disability status scale,EDSS)评分没有明显相关性。结论采用3D p CASL技术定量分析RRMS患者微循环的脑血流灌注情况发现,在常规MRI没有明显病变的NAWM的CBF值明显降低。该研究表明RRMS患者NAWM存在潜在的血流动力学改变,进一步提示血流动力学因素在RRMS患者的发病中可能起着重要的作用。
文摘目的探讨使用时间-空间标记反转脉冲(time-spatial labeling inversion p u l s e,Ti m e-S L I P)非对比增强血管成像技术评价肾动脉的价值。材料与方法使用1.5 T MR扫描仪对36例临床怀疑肾动脉狭窄的患者行Time-SLIP磁共振血管造影术(magnetic resonance angiography,MRA)检查。以320排CT血管造影(computed tomography angiography,CTA)和数字减影血管造影(digital subtraction angiography,DSA)为参考标准,评价Time-SLIP肾动脉MRA的图像质量和诊断肾动脉狭窄的能力。结果共71支肾动脉纳入研究,图像质量优秀的有51支(72%),良好的有17支(24%),差的有3支(4%)。Time-SLIP MRA诊断肾动脉狭窄的敏感度、特异度分别为100%、98.2%,诊断明显狭窄(狭窄程度>50%)的敏感度、特异度分别为90%、98.4%。Time-SLIP MRA定量评估肾动脉狭窄程度与CTA和DSA呈高度相关(r=0.959,P<0.01),但Time-SLIP MRA轻度高估肾动脉的狭窄程度[平均偏倚为(3.31±10.04)%]。结论 Time-SLIP非对比增强血管成像技术能够准确评价肾动脉。
文摘目的探讨磁共振三维动脉自旋标记脑灌注成像(3D ASL)中不同标记后延迟时间(PLD)对急性脑梗死不同脑区血流量的影响。方法随机选取基底节区新发脑梗死患者15例,采用不同标记后延迟时间(PLD=1.5s和PLD=2.5s)进行3D-ASL检查。通过GE AW 4.6后处理工作站,分别获得不同PLD时间点的全脑血流量(CBF)图,选取双侧额、颞、顶、枕叶、小脑和基底节区为感兴趣区,其中基底节区选取弥散加权成像(DWI)上高信号梗死区域,测量患侧和对侧镜像区域的CBF值。采用配对t检验分析不同PLD时间各脑区CBF值之间的差异,以及相同PLD的各脑区患侧和对侧CBF值之间的差异。P值小于0.05为有统计学显著差异。结果不同PLD时间点比较发现,额、颞、顶、枕叶及小脑半球区域CBF值在PLD=1.5s均低于PLD=2.5s,具有统计学显著差异(P均<0.05);基底节区域的CBF值在PLD=1.5s和PLD=2.5s无统计学显著差异。相同PLD的各脑区患侧和对侧CBF值比较发现,在PLD=1.5s或2.5s,颞、顶、枕叶及小脑半球区域患侧与对侧的CBF值均无统计学显著差异;而额叶的患侧与对侧的CBF值在PLD=1.5s有统计学显著差异(P<0.05),在PLD=2.5s无统计学显著差异;基底节区的患侧与对侧的CBF值在两种不同的延迟时间均有统计学显著差异(P均<0.05)。结论急性脑梗死患者3D ASL成像不同PLD时间对脑血流量的定量分析具有重要影响,合理选择PLD时间参数有助于准确评估急性脑梗死的全脑血流灌注情况。
