PDF(Pubmed)
Abstract：
UNASSIGNED: In intracranial pathologic conditions of intracranial pressure (ICP) disturbance or hemodynamic instability, maintaining appropriate ICP may reduce the risk of ischemic brain injury. The change of ICP is often accompanied by the change of intracranial blood status. As a non-invasive functional imaging technique, the sensitivity of electrical impedance tomography (EIT) to cerebral hemodynamic changes has been preliminarily confirmed. However, no team has conducted a feasibility study on the dynamic detection of ICP by EIT technology from the perspective of non-invasive whole-brain blood perfusion monitoring. In this study, human brain EIT image sequence was obtained by in vivo measurement, from which a variety of indicators that can reflect the tidal changes of the whole brain impedance were extracted, in order to establish a new method for non-invasive monitoring of ICP changes from the level of cerebral blood perfusion monitoring.
UNASSIGNED: Valsalva maneuver (VM) was used to temporarily change the cerebral blood perfusion status of volunteers. The electrical impedance information of the brain during this process was continuously monitored by EIT device and real-time imaging was performed, and the hemodynamic indexes of bilateral middle cerebral arteries were monitored by transcranial Doppler (TCD). The changes in monitoring information obtained by the two techniques were compared and observed.
UNASSIGNED: The EIT imaging results indicated that the image sequence showed obvious tidal changes with the heart beating. Perfusion indicators of vascular pulsation obtained from EIT images decreased significantly during the stabilization phase of the intervention (PAC: 242.94 ± 100.83, p < 0.01); perfusion index which reflects vascular resistance increased significantly in the stable stage of intervention (PDT: 79.72 ± 18.23, p < 0.001). After the intervention, the parameters gradually returned to the baseline level before compression. The changes of EIT indexes in the whole process are consistent with the changes of middle cerebral artery velocity related indexes shown in TCD results.
UNASSIGNED: The EIT image combined with the blood perfusion index proposed in this paper can reflect the decrease of cerebral blood flow under the condition of increased ICP in real time and intuitively. With the advantages of high time resolution and high sensitivity, EIT provides a new idea for non-invasive bedside measurement of ICP.
UNASSIGNED: Valsalva maneuver (VM) was used to temporarily change the cerebral blood perfusion status of volunteers. The electrical impedance information of the brain during this process was continuously monitored by EIT device and real-time imaging was performed, and the hemodynamic indexes of bilateral middle cerebral arteries were monitored by transcranial Doppler (TCD). The changes in monitoring information obtained by the two techniques were compared and observed.
UNASSIGNED: The EIT imaging results indicated that the image sequence showed obvious tidal changes with the heart beating. Perfusion indicators of vascular pulsation obtained from EIT images decreased significantly during the stabilization phase of the intervention (PAC: 242.94 ± 100.83, p < 0.01); perfusion index which reflects vascular resistance increased significantly in the stable stage of intervention (PDT: 79.72 ± 18.23, p < 0.001). After the intervention, the parameters gradually returned to the baseline level before compression. The changes of EIT indexes in the whole process are consistent with the changes of middle cerebral artery velocity related indexes shown in TCD results.
UNASSIGNED: The EIT image combined with the blood perfusion index proposed in this paper can reflect the decrease of cerebral blood flow under the condition of increased ICP in real time and intuitively. With the advantages of high time resolution and high sensitivity, EIT provides a new idea for non-invasive bedside measurement of ICP.
摘要：
■在颅内压（ICP）紊乱或血流动力学不稳定的颅内病理情况下，维持适当的ICP可以降低缺血性脑损伤的风险。ICP的转变常伴随颅内血液状况的转变。作为一种非侵入性的功能成像技术，电阻抗断层扫描（EIT）对脑血流动力学变化的敏感性已得到初步证实。然而,没有团队从无创性全脑血流灌注监测的角度进行EIT技术动态检测ICP的可行性研究。在这项研究中,通过活体测量获得人脑EIT图像序列，从中提取了各种能够反映全脑阻抗的潮汐变化的指标,为了从脑血流灌注监测水平建立一种无创监测ICP变化的新方法。
■Valsalva机动（VM）用于暂时改变志愿者的脑血液灌注状态。在此过程中，通过EIT设备连续监测大脑的电阻抗信息，并进行实时成像，经颅多普勒（TCD）监测双侧大脑中动脉血流动力学指标。比较并观察了两种技术获得的监测信息的变化。
■EIT成像结果表明，图像序列随着心脏跳动而表现出明显的潮汐变化。从EIT图像获得的血管搏动的灌注指标在干预的稳定阶段显着降低（PAC：242.94±100.83，p<0.01）；反映血管阻力的灌注指数在干预的稳定阶段显着增加（PDT：79.72±18.23，p<0.001）。干预之后,参数逐渐恢复到压缩前的基线水平。整个过程中EIT指标的变化与TCD结果显示的大脑中动脉血流相关指标的变化一致。
■本文提出的EIT图像与血液灌注指数相结合，可以实时，直观地反映ICP升高条件下脑血流量的减少。具有时间分辨率高、灵敏度高等优点,EIT为ICP的无创床边测量提供了新思路。
■Valsalva机动（VM）用于暂时改变志愿者的脑血液灌注状态。在此过程中，通过EIT设备连续监测大脑的电阻抗信息，并进行实时成像，经颅多普勒（TCD）监测双侧大脑中动脉血流动力学指标。比较并观察了两种技术获得的监测信息的变化。
■EIT成像结果表明，图像序列随着心脏跳动而表现出明显的潮汐变化。从EIT图像获得的血管搏动的灌注指标在干预的稳定阶段显着降低（PAC：242.94±100.83，p<0.01）；反映血管阻力的灌注指数在干预的稳定阶段显着增加（PDT：79.72±18.23，p<0.001）。干预之后,参数逐渐恢复到压缩前的基线水平。整个过程中EIT指标的变化与TCD结果显示的大脑中动脉血流相关指标的变化一致。
■本文提出的EIT图像与血液灌注指数相结合，可以实时，直观地反映ICP升高条件下脑血流量的减少。具有时间分辨率高、灵敏度高等优点,EIT为ICP的无创床边测量提供了新思路。
