动脉自旋标记在MR灌注成像中的研究进展

随着MR成像技术的不断改进，动脉自旋标记技术作为一种MR灌注成像新方法已得到应用。它具有无创性、可重复性高和组织对比度较好的优点，目前已初步应用于脑、肾、肺及心脏等组织器官的灌注成像研究。     

动脉自旋标记在MR灌注成像中的研究进展

随着MR成像技术的不断改进,动脉自旋标记技术作为一种MR灌注成像新方法已得到应用.它具有无创性、可重复性高和组织对比度较好的优点,目前已初步应用于脑、肾、肺及心脏等组织器官的灌注成像研究.     

3D-ASL灌注成像技术对非增强型星形细胞瘤分级诊断的应用价值

目的 探讨三维动脉自旋标记(3D-ASL)灌注成像的肿瘤血流成像对非增强型颅脑星形细胞瘤分级的评估价值。方法 回顾性搜集2020年3月至2022年3月在本院就诊并经病理证实的25例非增强型颅脑星形细胞瘤患者作为研究对象,按肿瘤分级分为高级别组(n=15)和低级别组(n=10)。入组对象经MRI常规序列及ASL扫描后,计算出肿瘤的绝对最大肿瘤血流量(TBF_max)、绝对平均TBF(TBF_mean)以及相应的脑血流量(CBF)标准化值(TBF_max率和TBF_mean率)。使用独立样本t检验比较两组对象TBF_max、TBF_mean、TBF_max率、TBF_mean率的差异,应用受试者工作特征曲线(ROC)预测各指标对肿瘤分级评估的准确率。结果 与低级别组相比,高级别组TBF_max[(85.51±19.53)ml/100 g/min vs.(53.33±16.44) ml/100 g/min,P<...     

脑CT灌注成像在星形细胞瘤术前分级中的价值

目的:评价CT灌注成像在星形细胞瘤术前分级中的应用价值。方法:对29例星形细胞瘤患者行常规CT及CT灌注成像,所有病例分为2组:低级别星形细胞瘤15例,高级别星形细胞瘤14例。灌注成像先得到TDC,并合成局部脑血容量(rCBV)图和局部脑血流量(rCBF),计算出感兴趣区的rCBF、相对rCBV(rrCBV)、相对rCBF(rrCBF)和局部血管表面通透性(rP)。比较两组间的CT灌注参数,如果差异有显著性意义,用受试者工作特征(ROC)曲线判别各参数对区分低级、高级星形细胞瘤的效果。结果:低、高级星形细胞瘤的rCBF分别为46.95±22.92 ml.min-1.100g-1,95.44±42.58 ml.min-1.100g-1;rrCBF分别为2.19±0.98,4.65±1.73;rrCBV分别为3.53±2.39,8.32±5.75;rP(中位数,四分位数间距)分别为(0.09,0.12),(0.30,0.39)。CT灌注参数诊断低、高级星形细胞瘤的效果:rCBFr、rCBFr、rCBVr、P的ROC曲线下面积分别为0.848、0.900、0.786、0.940。结论:rrCBVr、rCBF和rP均能可靠地评价星形细胞瘤的术前病理级别;在满足计算公式的前提条件下,rCBF绝对值和其它相对灌注参数一样,能可靠地评价星形细胞瘤的术前病理级别。     

动脉自旋标记MR灌注成像对脑膜瘤病理分型的鉴别诊断

目的 研究动脉自旋标记(ASL)MR灌注成像对脑膜瘤病理分型鉴别诊断及临床应用价值.方法 对经手术病理证实的45例脑膜瘤患者术前行三维动脉自旋标记(3 D-ASL)、MRI平扫及增强序列扫描.测量ASL MR血流灌注图中肿瘤实质部分最大肿瘤血流量(TBF)和对侧镜像脑血流量(CBF),采用SPSS 25.0统计软件进行...     

MR灌注成像在脑星形细胞瘤术前分级中的应用价值

目的　评价MR灌注成像在脑星形细胞瘤术前分级中的应用价值。资料与方法　对 34例脑星形细胞瘤患者行常规MRI及MR灌注成像 ,所有病例分为 3组 :低级别星形细胞瘤 (LGA) 12例 ,间变性星形细胞瘤 (AA) 13例 ,胶质母细胞瘤 (GBM) 9例。灌注成像先得到信号强度 时间曲线 ,并合成局部脑血容量 (rCBV)图 ,计算相对局部脑血容量 (rrCBV)。计算出感兴趣区对比剂首过期末的信号下降百分率 ,作出对比剂平均通过时间 (MTT)图 ,得出MTT值 ,计算出微血管相对渗透值 (rP)。结果　LGA、AA及GBM最大rrCBV分别为 3.2 3± 0 .92 ,5 .0 5± 0 .6 6 ,5 .18± 0 .34;3组的微血管rP分别为 1.34± 0 .4 6 ,2 .17± 0 .2 8,2 .5 9± 0 .6 0。 3组间的rrCBV及rP值均有显著性差异 ,rP与rCBV有明显正相关 (r=0 .85 3,P <0 .0 1)。结论　MR灌注成像参数rrCBV、rP能在术前可靠地评价星形细胞瘤的病理级别。     

动脉自旋标记灌注成像在癫痫的研究进展

癫痫是脑神经元异常放电引起反复痫性发作的脑功能失调综合征。对癫痫病人脑功能的研究成为近年来的研究热点。其中动脉自旋标记(ASL)灌注成像是一种无创定量测量脑血流灌注量的MR功能成像新技术,可以反映癫痫病人脑血流动力学的相关情况,能为更好地揭示癫痫的病理生理机制提供新的理论依据。就ASL新技术在癫痫的研究进展及临床应用进行综述。     

DWI与动脉自旋标记成像在胶质瘤术前诊断中的应用价值

目的 :探讨DWI及动脉自旋标记法(arterial spin labeling,ASL)在胶质瘤术前分级中的应用价值。方法:选取28例经手术病理证实的脑肿瘤患者,其中高级别胶质瘤(high grade glioma,HGG)18例,低级别胶质瘤(low grade glioma,LGG)10例。所有患者均行DWI及ASL扫描,比较不同级别胶质瘤ADC值及脑血流量(CBF)值的差异。结果:HGG肿瘤实质区CBF值大于LGG;HGG肿瘤实质区ADC值小于LGG;且不同级别胶质瘤ADC值与CBF值有显著相关性(r=-0.759,P=0.002)。结论 :DWI及ASL可于术前安全无创地评估脑胶质瘤级别,有助于临床制订治疗方案。     

~1H-MRS在脑星形细胞瘤术前分级中的价值

星形细胞瘤(astrocytoma,AS)的病理分级对诊断、预后和治疗计划的制定至关重要。质子磁共振波谱成像(proton magnetic resonance spectroscopy,1H-MRS)能够无创性检测肿瘤组织及周围区域代谢物的变化,目前在临床上已用于胶质瘤的分级、诊断、病变范围确定及鉴别诊断。另外,如何     

1.5T场强MR动脉自旋标记灌注成像在脑梗死中的初步应用

目的：探讨采用1.5T场强MR动脉自旋标记灌注成像（ASL-PWI）评价脑梗死的可行性。方法：对34例临床和MRI发现脑梗死的患者行常规MRI、扩散加权成像（DWI）及ASL-PWI扫描,根据Adamas分类将急性脑梗死分为大面积和小面积2组,比较DWI和ASL-PWI上病变的范围,比较病变区CBF值（CBF病变）与对侧正常区CBF值（CBF正常）。结果：20例大面积脑梗死中5例ASL-PWI显示病灶范围较DWI大,9例两者显示范围相当,5例前者小于后者,1例未见异常灌注区;14例小面积脑梗死中6例显示低灌注区,7例未能明确显示低灌注区,1例灌注增强;除1例灌注增强病例CBF病变大于CBF正常外,其它均小于后者。结论：在1.5T磁场强度上应用ASL-PWI技术能基本反映脑梗死区血流灌注的改变,其严格的相关性及临床意义有待于进一步探索。     

MR perfusion imaging using the arterial spin labeling technique for breast cancer

Purpose:

To investigate the feasibility of perfusion imaging using an arterial spin labeling (ASL) technique for breast cancer.

Materials and Methods:

Thirteen female patients with primary breast cancers were included in this study. All examinations were performed on 1.5 Tesla MRI systems. Visual evaluations of the colored perfusion map and MRI perfusion values were assessed. MRI and computed tomography (CT) perfusion values were compared.

Results:

Thirteen of 14 tumor lesions could be visualized on the colored perfusion map. CT perfusion examinations were performed in eight breasts, and the relationship between the blood flow values of CT perfusion and of MR perfusion showed a significant correlation.

Conclusion:

Nonenhanced MR imaging by an ASL technique is valid for depicting breast cancer, and the MR perfusion value is thought to be helpful for quantitative diagnosis of breast cancer. J. Magn. Reson. Imaging 2012;436‐440. © 2011 Wiley Periodicals, Inc.     

3.0T磁共振动脉自旋标记(ASL)技术诊断前列腺癌

目的:探讨前列腺磁共振动脉自旋标记(ASL)检查的影像学表现及ASL检查在前列腺癌诊断中的价值。方法:35例临床疑似前列腺肿瘤的患者行磁共振检查(包括常规T1WI和T2WI及ASL检查),回顾性分析ASL检查对前列腺肿瘤的诊断价值。以穿刺病理检查结果作为金标准将患者分为两组:前列腺肿瘤组17例,年龄16～84岁,平均63.5岁,总PSA(TPSA)0.76～1733.24ng/ml,平均207.77ng/ml;非前列腺肿瘤组18例,年龄51～80岁,平均77.3岁,总PSA 0.55～94.79ng/ml,平均13.71ng/ml。其中的12例非前列腺肿瘤和10例前列腺肿瘤患者再行磁共振灌注成像(PWI)检查。结果:ASL检查中18例非前列腺肿瘤患者前列腺外周叶和中央带平均灌注值分别为(104.19±1.65)和(137.79±1.74)ml/(100g.min);17例前列腺肿瘤患者外周叶肿瘤和中央带肿瘤的平均灌注值分别为(152.80±3.38)和(170.47±5.34)ml/(100g.min)。PWI检查中12例非前列腺肿瘤患者外围叶和中央带平均灌注值分别为(176.55±21.44)和(597.30±34.97)ml/(100g.min);10例前列腺肿瘤患者外围叶肿瘤和中央带肿瘤平均灌注值分别为(449.98±21.44)和(756.74±41.14)ml/(100g.min)。经统计学分析,前列腺非肿瘤外围叶与中央带、前列腺非肿瘤外围叶与前列腺外围叶肿瘤以及前列腺非肿瘤中央带与前列腺中央带肿瘤ASL检查平均灌注值差异均具有显著性意义(P<0.05)。结论:对于由于肾功能不良或者其它原因不能进行PWI检查而疑似前列腺肿瘤的患者可借助磁共振ASL检查明确诊断。     

VE-ASL MRI评价脑动脉侧支循环——与DSA比较

目的:使用血管编码动脉自旋标记(VE-ASL)技术在评价颈动脉狭窄患者通过Willis环与软脑膜动脉形成的侧支循环中的价值。方法:对经超声检查诊断为单侧颈内动脉中度以上狭窄或大脑中动脉血流速度明显增加的10例患者,行VE-ASL MRI检查,测量连续7个脑部层面(层厚8mm,间隔2mm),使用红绿蓝三种伪彩色分别标记来源于右侧颈内动脉、左侧颈内动脉和后循环的血流。所有患者在MRI检查前后1周内行DSA检查。将狭窄侧大脑半球侧支循环情况分为4种类型。Ⅰ型:仅来源于对侧颈内动脉;Ⅱ型:仅来源于后循环;Ⅲ型:既来源于对侧颈内动脉,也来源于后循环;Ⅳ型:既无对侧颈内动脉供血,也无后循环的侧支供血。记录患者侧支血流中软脑膜动脉侧支的数目。计算卡帕值比较两种测量方法之间的一致性。结果:比较VE-ASL和DSA方法,DSA对侧支循环的分型结果为Ⅰ型1例,Ⅱ型2例,Ⅲ型5例,Ⅳ型2例;VE-ASL分型结果为Ⅰ型1例,Ⅱ型3例,Ⅲ型4例,Ⅳ型2例。两种检查方法的诊断一致性非常好(Kappa=0.8551,Z=4.421,P<0.0001)10例中观察到6例8处软脑膜侧支血流。结论:对颈内动脉狭窄患者,VE-ASL可以无创地评价脑动脉通过Willis环及软脑膜动脉形成的侧支循环。     

Reproducibility of renal perfusion MR imaging in native and transplanted kidneys using non-contrast arterial spin labeling

Purpose:

To examine both inter‐visit and intra‐visit reproducibility of a MR arterial spin labeling (ASL) perfusion technique in native and transplanted kidneys over a broad range of renal function.

Materials and Methods:

Renal perfusion exams were performed at 1.5 T in a total of 24 subjects: 10 with native and 14 with transplanted kidneys. Using a flow‐sensitive alternating inversion recovery (FAIR) ASL scheme, 32 control/tag pairs were acquired and processed using a single‐compartment model. Two FAIR‐ASL MR exams were performed at least 24 h apart on all the subjects to assess inter‐visit reproducibility. ASL perfusion measurements were also repeated back‐to‐back within one scanning session in 8 native subjects and in 12 transplant subjects to assess intra‐visit reproducibility. Intra‐class correlations (ICCs) and coefficients of variation (CVs) were calculated as metrics of reproducibility.

Results:

Intra‐visit ICCs ranged from 0.96 to 0.98 while CVs ranged from 4.8 to 6.0%. Inter‐visit measurements demonstrated slightly more variation with ICCs from 0.89 to 0.94 and CVs from 7.6 to 13.1%. Medullary perfusion demonstrated greater variability compared with cortical blood flow: intra‐visit ICCs from 0.72 to 0.78 and CVs from 16.7 to 26.7%, inter‐visit ICCs from 0.13 to 0.63 and CVs from 19.8 to 37%.

Conclusion:

This study indicates that a FAIR‐ASL perfusion technique is reproducible in the cortex of native and transplanted kidneys over a broad range in renal function. In contrast, perfusion measurements in the medulla demonstrated moderate to poor reproducibility for intra‐visit and inter‐visit measures respectively. J. Magn. Reson. Imaging 2011;33:1414–1421. © 2011 Wiley‐Liss, Inc.     

动脉自旋标记灌注成像对软组织VX2肿瘤血管生成的评价

目的 评价有关兔软组织VX2肿瘤血管生成的2个病理学指标,即微血管密度(MVD)和血管内皮生长因子(VEGF)表达水平与MR动脉自旋标记(ASL)灌注成像所测血流量(BF)值的相关性.方法 将VX2肿瘤接种于18只新西兰兔右侧后腿肌肉内,3～4周后对实验兔行ASL灌注成像检查.所得图像被传输到一台独立的计算机进行处理,生成BF参数图,测量在肿瘤内所选2～4个ROI的BF值.随后处死实验用兔,获取肿瘤标本,在与ASL灌注图像上的ROI相对应的非坏死部分进行取材,对所获肿瘤组织行CD31和VEGF免疫组织化学染色,然后测量其MVD和VEGF表达水平.采用Spearman相关分析法评价VX2肿瘤组织的MVD和VEGF表达水平与BF值的相关性.结果 BF参数图显示存活肿瘤组织与肌肉相比呈明显的高BF值,部分肿瘤内可见血流灌注缺失区.显微镜下,CD31抗体标记染色的微小血管呈棕黄色染色区域;VEGF染色阳性者则表现为胞质内出现棕红色的区域.共分析了39块VX2肿瘤组织,其BF(M值为6.4 ml·100 g-1·min-1)与肿瘤的MVD(M值为6.8条/个视野)呈显著正相关(r=0.906,P＜0.01),与VEGF表达水平(M值为8%)无明显相关(r=0.116,P=0.483).结论 BF值通过反映肿瘤的MVD可用于评价肿瘤的血管生成情况,从而帮助判断其预后并指导治疗.     

Application of arterial spin labeling perfusion MRI to differentiate benign from malignant intracranial meningiomas

PurposeDifferentiating WHO grade I–III of meningioma by non-invasive imaging is challenging. This study investigated the potential of MR arterial spin labeling (ASL) to establish tumor grade in meningioma patients.Material and methodsPseudo-continuous ASL with 3D background suppressed gradient and spin echo (GRASE) was acquired on 54 patients with newly diagnosed or recurrent intracranial meningioma. Perfusion patterns characterized in CBF color maps were independently evaluated by three neuroradiologists blinded to patient history, and correlated with tumor grade from histo-pathological review.ResultsThree perfusion patterns could be discerned by visual evaluation of CBF maps. Pattern 1 consisted of homogeneous hyper-perfusion of the entire tumor; pattern 2 demonstrated heterogeneous hyper-perfusion; pattern 3 showed no substantial hyper-perfusion. Evaluation of the perfusion patterns was highly concordant among the three readers (Kendall W = 0.9458, P < 0.0001). Pattern 1 was associated with WHO Grade I meningioma of (P < 0.0001). Patterns 2 and 3 were predictive of WHO Grade II and III meningioma (P < 0.0001), with an odds ratio (OR, versus pattern 1) of 49.6 (P < 0.01) in a univariate analysis, and an OR of 186.4 (P < 0.01) in a multivariate analysis.ConclusionQualitative evaluation of ASL CBF maps can help differentiate benign (WHO Grade I) from higher grade (WHO Grade II and III) intracranial meningiomas, potentially impacting therapeutic strategy.