双层探测器光谱CT血管成像评估急性缺血性脑卒中灌注的价值

The application value of dual-layer detector spectral CT angiography in evaluation of brain perfusion in patients with acute ischemic stroke

目的探讨双层探测器光谱CT颅脑血管成像(CTA)评估急性缺血性脑卒中脑组织灌注缺损的价值。方法回顾性分析2020年3月至10月在威海市中心医院诊断为急性缺血性脑卒中35例患者的临床及影像资料。所有患者均接受双层探测器头颈部光谱CTA及颅脑CT灌注成像(CTP)检查。在CTA重建的碘密度图及有效原子序数图上测量并比较灌注缺损区及健侧的碘密度值、有效原子序数值,在CTP图像上测量并比较患侧与健侧脑血容量(CBV)值、脑血流量(CBF)值,同时测量脑灌注缺损面积。采用Pearson相关系数分析碘密度值与CBV值、碘密度值与CBF值、有效原子序数值与CBV值、有效原子序数值与CBF值、CTA显示的脑灌注缺损面积与CTP-CBF显示的脑灌注缺损面积之间的相关性。结果35例急性缺血性脑卒中患者患侧碘密度值[(0.22±0.07)mg/ml]、有效原子序数值(7.38±0.05)、CBV值[(1.9±0.7)ml/100 g]、CBF值[(15.1±5.9)ml/(100 g·min)]均显著低于健侧[碘密度值(0.44±0.10)mg/ml、有效原子序数值(7.52±0.06)、CBV值(3.4±0.7)ml/100 g、CBF值(57±27)ml/(100 g·min),t值分别为-14.7、-14.5、-11.2、-9.7,P<0.001];光谱CTA显示的脑缺血面积[(2292±1393)mm2]与CTP-CBF图显示的脑缺血面积[(2290±1359)mm2]差异无统计学意义(t=-0.076,P=0.944)。急性缺血性脑卒中患者的碘密度值与CBV值呈正相关(患侧为r=0.350,P=0.039;健侧为r=0.551,P=0.001);有效原子序数值与CBV值呈正相关(患侧为r=0.488,P=0.003;健侧为r=0.552,P=0.001);光谱CTA显示的脑灌注缺损面积与CTP显示的脑灌注缺损面积存在强相关性(r=0.993,P<0.001)。结论双层探测器光谱CTA可实现对颅内血管狭窄或闭塞情况、脑组织灌注缺损程度“一站式”评估,为急性缺血性脑卒中患者提供了一种更快捷的评估方法。

Objective To explore the clinical application value of the dual-layer detector spectral CTA in evaluation of brain perfusion impairment in patients with acute ischemic stroke.Methods Clinical and imaging data of 35 patients with acute ischemic stroke in Weihai Central Hospital from March 2020 to October 2020 were reviewed retrospectively.All patients underwent head and neck spectral CTA examination and dynamic cerebral perfusion CT examination with dual-layer detector spectral CT.The iodine density map and effective atomic number map were reconstructed using CTA data,and the iodine density and effective atomic number,as well as the cerebral blood volume(CBV)and cerebral blood flow(CBF)values of the hypoperfusion area and the contralateral side were measured and compared;the areas of brain hypoperfusion regions were measured.Pearson′s correlation coefficient was used to analyze the correlation between iodine density values and CBV values,iodine density values and CBF values,effective atomic number values and CBV values,effective atomic number values and CBF values,as well as hypoperfusion area shown on CTA images and displayed on CTP-CBF map.Results Of all the 35 patients,the iodine density value[(0.22±0.07)mg/ml],effective atomic number value(7.38±0.05),CBV value[(1.9±0.7)ml/100 g]and CBF value[(15.1±5.9)ml/(100 g·min)]of the hypoperfusion area were significantly lower than those of the healthy side[iodine density value(0.44±0.10)mg/ml,effective atomic number value(7.52±0.06),CBV value(3.4±0.7)ml/100 g,CBF value(57±27)ml/(100 g·min);t values were-14.7,-14.5,-11.2,-9.7,respectively,all P<0.001].No significant difference was found between the hypoperfusion area shown on spectral CTA[(2292±1393)mm2]and shown on CTP-CBF map[(2290±1359)mm2](t=-0.076,P=0.944).There was a positive correlation between iodine density value and CBV(affected side:r=0.350,P=0.039,healthy side:r=0.551,P=0.001);a positive correlation was also found between effective atomic number value and CBV(affected side:r=0.488,P=0.003,healthy side:r=0.552,P=0.001);and there was a strong positive correlation between the hypoperfusion area on CTA and that on CTP-CBF(r=0.993,P<0.001).Conclusion Dual-layer detector spectral CTA can provide the“one-stop”assessement including head and neck vascular evaluation,as well as the hypoperfution area measument,which can be an alternative rapid method for evaluation of patients with acute ischemic stroke.