BACKGROUND It is of vital importance to find radiologic biomarkers that can accurately predict treatment response. Usually, the initiation of antiangiogenic therapy causes a rapid decrease in the contrast enhancing tu...BACKGROUND It is of vital importance to find radiologic biomarkers that can accurately predict treatment response. Usually, the initiation of antiangiogenic therapy causes a rapid decrease in the contrast enhancing tumor. However, the treatment response is observed only in a fraction of patients due to the partial radiological response secondary to stabilization of abnormal vessels which does not essentially indicate a true antitumor effect. Perfusion-weighted magnetic resonance imaging(PWMRI) techniques have shown implicitness as a strong imaging biomarker for gliomas since they give hemodynamic information of blood vessels. Hence, there is a rapid expansion of PW-MRI related studies and clinical applications.AIM To determine the diagnostic performance of PW-MRI techniques including:(A)dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI); and(B)dynamic susceptibility contrast magnetic resonance imaging(DSC-MRI) for evaluating response to antiangiogenic therapy in patients with recurrent gliomas.METHODS Databases such as PubMed(MEDLINE included), EMBASE, and Google Scholar were searched for relevant original articles. The included studies were assessed for methodological quality with the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Medical imaging follow-up or histopathological analysis was used as the reference standard. The data were extracted by two reviewers independently, and then the sensitivity, specificity, summary receiver operating characteristic curve, area under the curve(AUC), and heterogeneity were calculated using Meta-Disc 1.4 software.RESULTS This study analyzed a total of six articles. The overall sensitivity for DCE-MRI and DSC-MRI was 0.69 [95% confidence interval(CI): 0.53-0.82], and the specificity was 0.99(95%CI: 0.93-1) by a random effects model(DerSimonianeeLaird model). The likelihood ratio(LR) +, LR-, and diagnostic odds ratio(DOR)were 12.84(4.54-36.28), 0.35(0.22-0.53), and 24.44(7.19-83.06), respectively. The AUC(± SE) was 0.9921(± 0.0120), and the Q* index(± SE) was 0.9640(± 0.0323).For DSC-MRI, the sensitivity was 0.73, the specificity was 0.98, the LR+ was 7.82,the LR-was 0.32, the DOR was 31.65, the AUC(± SE) was 0.9925(± 0.0132), and the Q* index was 0.9649(± 0.0363). For DCE-MRI, the sensitivity was 0.41, the specificity was 0.97, the LR+ was 5.34, the LR-was 0.71, the DOR was 8.76, the AUC(± SE) was 0.9922(± 0.2218), and the Q* index was 0.8935(± 0.3037).CONCLUSION This meta-analysis demonstrated a beneficial value of PW-MRI(DSC-MRI and DCE-MRI) in monitoring the response of recurrent gliomas to antiangiogenic therapy, with reasonable sensitivity, specificity, +LR, and-LR.展开更多
目的比较多参数三维假连续式动脉自旋标记灌注成像(3D p CASL)与动态磁敏感增强灌注成像(DSC PWI)对短暂性脑缺血发作(TIA)责任病灶的检出率。方法比较39例临床诊断TIA患者,并在首次发作24 h内进行磁共振检查。扫描序列包括常规头颅MR...目的比较多参数三维假连续式动脉自旋标记灌注成像(3D p CASL)与动态磁敏感增强灌注成像(DSC PWI)对短暂性脑缺血发作(TIA)责任病灶的检出率。方法比较39例临床诊断TIA患者,并在首次发作24 h内进行磁共振检查。扫描序列包括常规头颅MR成像、MRA(MRA),DWI、3D p CASL(选取两个标记延迟时间post-labeling time,PLD,PLD=1.5 s及PLD=2.5 s),DSC PWI。后处理获取3D p CASL的脑血流(CBF)图像和DSC PWI的Tmax图像。比较不同灌注方法与MRA及DWI结合法对于缺血病灶检出率和缺血面积。结果 TIA患者的缺血病灶检出率,3D p CASL(PLD1.5 s及PLD2.5 s)的CBF图像与DSC PWI Tmax对比无差异;3D p CASL(PLD1.5 s)的CBF图像对于缺血的检出率高于MRA结合DWI法;DSC PWI Tmax、3D p CASL(PLD2.5 s)CBF与MRA结合DWI法无差异。显示低灌注面积,3D p CASL(PLD1.5 s)的CBF图像显示的面积最大,其次是DSC PWI Tmax,而3D p CASL(PLD2.5 s)的CBF图像显示的低灌注面积最小。结论 3D p CASL脑灌注成像技术无创、快速、可重复性强,推荐作为临床可疑TIA患者的影像筛查手段,不同PLD的3D p CASL序列对于病灶的检出及缺血面积的显示有差异,选择较短PLD有可能提高病灶的检出率。展开更多
Summary： The purpose of this study was to quantitatively analyze the relationship between three di- mensional arterial spin labeling （3D-ASL） and dynamic susceptibility contrast-enhanced perfusion weighted imaging ...Summary： The purpose of this study was to quantitatively analyze the relationship between three di- mensional arterial spin labeling （3D-ASL） and dynamic susceptibility contrast-enhanced perfusion weighted imaging （DSC-PWI） in ischemic stroke patients. Thirty patients with ischemic stroke were in- cluded in this study. All subjects underwent routine magnetic resonance imaging scanning, diffusion weighted imaging （DWI）, magnetic resonance angiography （MRA）, 3D-ASL and DSC-PWI on a 3.0T MR scanner. Regions of interest （ROIs） were drawn on the cerebral blood flow （CBF） maps （derived from ASL） and multi-parametric DSC perfusion maps, and then, the absolute and relative values of ASL-CBF, DSC-derived CBF, and DSC-derived mean transit time （MTT） were calculated. The rela- tionships between ASL and DSC parameters were analyzed using Pearson＇s correlation analysis. Re- ceiver operative characteristic （ROC） curves were performed to define the thresholds of relative value of ASL-CBF （rASL） that could best predict DSC-CBF reduction and MTT prolongation. Relative ASL better correlated with CBF and MTT in the anterior circulation with the Pearson correlation coefficients （R） values being 0.611 （P〈0.001） and-0.610 （P〈0.001） respectively. ROC curves demonstrated that when rASL 〈0.585, the sensitivity, specificity and accuracy for predicting ROIs with rCBF〈0.9 were 92.3%, 63.6% and 76.6% respectively. When rASL 〈0.952, the sensitivity, specificity and accuracy for predicting ROIs rMTT〉I.0 were 75.7%, 89.2% and 87.8% respectively. ASL-CBF map has better linear correlations with DSC-derived parameters （DSC-CBF and MTT） in anterior circulation in ischemic stroke patients. Additionally, when rASL is lower than 0.585, it could predict DSC-CBF decrease with moderate accuracy. IfrASL values range from 0.585 to 0.952, we just speculate the prolonged MTT.展开更多
文摘BACKGROUND It is of vital importance to find radiologic biomarkers that can accurately predict treatment response. Usually, the initiation of antiangiogenic therapy causes a rapid decrease in the contrast enhancing tumor. However, the treatment response is observed only in a fraction of patients due to the partial radiological response secondary to stabilization of abnormal vessels which does not essentially indicate a true antitumor effect. Perfusion-weighted magnetic resonance imaging(PWMRI) techniques have shown implicitness as a strong imaging biomarker for gliomas since they give hemodynamic information of blood vessels. Hence, there is a rapid expansion of PW-MRI related studies and clinical applications.AIM To determine the diagnostic performance of PW-MRI techniques including:(A)dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI); and(B)dynamic susceptibility contrast magnetic resonance imaging(DSC-MRI) for evaluating response to antiangiogenic therapy in patients with recurrent gliomas.METHODS Databases such as PubMed(MEDLINE included), EMBASE, and Google Scholar were searched for relevant original articles. The included studies were assessed for methodological quality with the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Medical imaging follow-up or histopathological analysis was used as the reference standard. The data were extracted by two reviewers independently, and then the sensitivity, specificity, summary receiver operating characteristic curve, area under the curve(AUC), and heterogeneity were calculated using Meta-Disc 1.4 software.RESULTS This study analyzed a total of six articles. The overall sensitivity for DCE-MRI and DSC-MRI was 0.69 [95% confidence interval(CI): 0.53-0.82], and the specificity was 0.99(95%CI: 0.93-1) by a random effects model(DerSimonianeeLaird model). The likelihood ratio(LR) +, LR-, and diagnostic odds ratio(DOR)were 12.84(4.54-36.28), 0.35(0.22-0.53), and 24.44(7.19-83.06), respectively. The AUC(± SE) was 0.9921(± 0.0120), and the Q* index(± SE) was 0.9640(± 0.0323).For DSC-MRI, the sensitivity was 0.73, the specificity was 0.98, the LR+ was 7.82,the LR-was 0.32, the DOR was 31.65, the AUC(± SE) was 0.9925(± 0.0132), and the Q* index was 0.9649(± 0.0363). For DCE-MRI, the sensitivity was 0.41, the specificity was 0.97, the LR+ was 5.34, the LR-was 0.71, the DOR was 8.76, the AUC(± SE) was 0.9922(± 0.2218), and the Q* index was 0.8935(± 0.3037).CONCLUSION This meta-analysis demonstrated a beneficial value of PW-MRI(DSC-MRI and DCE-MRI) in monitoring the response of recurrent gliomas to antiangiogenic therapy, with reasonable sensitivity, specificity, +LR, and-LR.
文摘目的比较多参数三维假连续式动脉自旋标记灌注成像(3D p CASL)与动态磁敏感增强灌注成像(DSC PWI)对短暂性脑缺血发作(TIA)责任病灶的检出率。方法比较39例临床诊断TIA患者,并在首次发作24 h内进行磁共振检查。扫描序列包括常规头颅MR成像、MRA(MRA),DWI、3D p CASL(选取两个标记延迟时间post-labeling time,PLD,PLD=1.5 s及PLD=2.5 s),DSC PWI。后处理获取3D p CASL的脑血流(CBF)图像和DSC PWI的Tmax图像。比较不同灌注方法与MRA及DWI结合法对于缺血病灶检出率和缺血面积。结果 TIA患者的缺血病灶检出率,3D p CASL(PLD1.5 s及PLD2.5 s)的CBF图像与DSC PWI Tmax对比无差异;3D p CASL(PLD1.5 s)的CBF图像对于缺血的检出率高于MRA结合DWI法;DSC PWI Tmax、3D p CASL(PLD2.5 s)CBF与MRA结合DWI法无差异。显示低灌注面积,3D p CASL(PLD1.5 s)的CBF图像显示的面积最大,其次是DSC PWI Tmax,而3D p CASL(PLD2.5 s)的CBF图像显示的低灌注面积最小。结论 3D p CASL脑灌注成像技术无创、快速、可重复性强,推荐作为临床可疑TIA患者的影像筛查手段,不同PLD的3D p CASL序列对于病灶的检出及缺血面积的显示有差异,选择较短PLD有可能提高病灶的检出率。
基金supported by grants from the 12th Five-year Science and Technology Support Program of China(No.2011BAI08B10)the National Natural Science Foundation of China(No.81171308,No.81570462)
文摘Summary： The purpose of this study was to quantitatively analyze the relationship between three di- mensional arterial spin labeling （3D-ASL） and dynamic susceptibility contrast-enhanced perfusion weighted imaging （DSC-PWI） in ischemic stroke patients. Thirty patients with ischemic stroke were in- cluded in this study. All subjects underwent routine magnetic resonance imaging scanning, diffusion weighted imaging （DWI）, magnetic resonance angiography （MRA）, 3D-ASL and DSC-PWI on a 3.0T MR scanner. Regions of interest （ROIs） were drawn on the cerebral blood flow （CBF） maps （derived from ASL） and multi-parametric DSC perfusion maps, and then, the absolute and relative values of ASL-CBF, DSC-derived CBF, and DSC-derived mean transit time （MTT） were calculated. The rela- tionships between ASL and DSC parameters were analyzed using Pearson＇s correlation analysis. Re- ceiver operative characteristic （ROC） curves were performed to define the thresholds of relative value of ASL-CBF （rASL） that could best predict DSC-CBF reduction and MTT prolongation. Relative ASL better correlated with CBF and MTT in the anterior circulation with the Pearson correlation coefficients （R） values being 0.611 （P〈0.001） and-0.610 （P〈0.001） respectively. ROC curves demonstrated that when rASL 〈0.585, the sensitivity, specificity and accuracy for predicting ROIs with rCBF〈0.9 were 92.3%, 63.6% and 76.6% respectively. When rASL 〈0.952, the sensitivity, specificity and accuracy for predicting ROIs rMTT〉I.0 were 75.7%, 89.2% and 87.8% respectively. ASL-CBF map has better linear correlations with DSC-derived parameters （DSC-CBF and MTT） in anterior circulation in ischemic stroke patients. Additionally, when rASL is lower than 0.585, it could predict DSC-CBF decrease with moderate accuracy. IfrASL values range from 0.585 to 0.952, we just speculate the prolonged MTT.
