床旁超声和CT重建测量视神经鞘直径监测颅内压的比较研究

Comparison of bedside ultrasonography and CT reconstruction technology in measurement of optic nerve sheath diameter

目的证实视神经鞘直径(ONSD)测量可以用于神经重症患者的颅内压(ICP)判断,且对超声和CT两种方法的诊断效能进行比较。方法对35例患者使用有创ICP监测仪监测ICP,完成床旁超声ONSD测量,在CT室内再次完成床旁超声ONSD测量及颅脑及眼眶CT检测,24h内完成视神经三维重建。运用ROC曲线判断ICP升高(ICP>20mm Hg)的ONSD最佳临界值。并对比床旁超声和CT重建两种方法测定ONSD的相关性及差异。结果 (1)床旁超声ONSD中位值0.45(0.42~0.50)cm。ICP≤20mm Hg组ICP与ONSD呈正相关(r=0.276,P=0.025),ICP>20mm Hg组ICP与ONSD呈正相关(r=0.748,P=0.001)。ROC曲线其AUC为0.922(95%CI:86.5%~98%,P=0.001),最大值约登指数为0.741,相应ONSD临界值为0.48cm(灵敏度86%,特异度88%)。(2)视神经CT重建技术测量视神经鞘直径,中位值0.61(0.58~0.66)cm。ICP≤20mm Hg组ICP与CT测量ONSD呈正相关(r=0.342,P=0.041),ICP>20mm Hg组ICP与CT测量ONSD呈正相关(r=0.662,P=0.001)。ROC曲线其AUC为0.931(95%CI:87.2%~99%,P=0.001),约登指数为0.648,相应ONSD临界值为0.62cm(灵敏度73.1%,特异度92%)。(3)对床旁超声及CT扫描测量ONSD进行对比,其中床旁超声ONSD中位值0.45(0.39~0.50)cm,CT重建ONSD中位值0.61(0.58~0.66)cm,两侧成线性相关,相关系数为0.812。结论床旁超声及CT重建两种方法测量ONSD对于判断ICP>20mm Hg均具有良好的灵敏度和特异度,两者均为无创监测ICP的重要手段。

Objective To compare bedside ultrasonography and CT reconstruction technique in measurement of optic nerve sheath diameter （ONSD）. Methods Thirty five patients admitted in Emergency ICU of Ningbo Second Hospital from October 2014 to October 2015 were enrolled in the study. The intracranial pressure （ICP） was monitored by invasive intracranial pressure monitoring device and the completed ONSD measurement was performed by ultrasonography in EICU. Completed brain and orbit CT scanning was performed and bedside ultrasound ONSD was measured again, then optic nerve three-dimensional reconstruction was completed within 24h. When intracranial pressure change exceeded 5 mmHg and lasted for 5min, the bedside ultrasound ONSD measurement was immediately completed. ROC curve was used to decide the best ONSD cut-off value to judge ICP rise （〉20mmHg）. And the correlation between ONSDs measured by bedside ultrasound and CT reconstruction was analyzed. Results The median ONSD measured by bedside ultrasound was 0.45 （0.42-0.50） cm. ICP was positively correlated with ONSD （ICP≤20mmHg group r=0.276, P〈0.05; ICP〉20mmHg group r= 0.748, P〈0.05）. AUC of ROC curve was 0.922 （95%CI： 86.5%- 98%, P = 0.001）. When the cut-off value of ONSD was 0.48cm, sensitivity, specificity and Youden index were 86%, 88% and 0.741, respectively. The mean value of ONSD measured by optic nerve CT reconstruction technology was 0.61 （0.58-0.66） cm. ICP was positively correlated with ONSD （ICP ≤20mmHg group r=0.342, P〈0.05; ICP 〉 20mmHg group r=0.662, P〈0.05）. AUC of ROC curve was 0.931 （95%CI： 87.2%-98%, P = 0.001）, when the cut-off value of ONSD was 0.62cm, the sensitivity, specificity and Youden index were 73.1%, 92% and 0.648, respectively. Thirty one patients completed ultrasound and CT scanning measurement ONSD within lh. Bedside ultrasound ONSD median was 0.45（0.39-0.50） cm, average value was （0.45 ± 0.057） cm. CT reconstruction ONSD median was 0.61（0.58-0.66） cm, average value was （0.63 ± 0.068） cm, the two sides were linearly dependent （r=0.812, P〈0.01）. Conclusion Bedside ultrasonography and CT reconstruc-tion both have good sensibility and specificity for noninvasive monitoring of ICP.