Study Of Electrical Impedance Tomography (EIT) In The Experimental Subarachnoid Hemorrhage Model Of Piglets

Subarachnoid hemorrhage is a fatal disease, which threatening patients'life. It is more likely to result in death or major disability among craniocerebral injury patients. Some of those diseases have a continuous bleeding character, and will cause even more serious results if no proper treatment been taken timely. Therefore, it is crucial to diagnose this kind of diseases as early as possible. However, the diagnoses of subarachnoid hemorrhage at present are based on the equipments such as X-ray CT and MRI were unfit for real-time monitoring. Thus they are unfit for the rapid diagnose of those continuous bleeding disease. As a result, some of those patient were misdiagnosed and been delayed.For electrical impedance tomography (EIT) technique has the advantages of harmless,low cost, easy to use and functional imaging. Those features make it more fit for long time imaging monitoring. Therefore, the final goal of this study is to imaging monitoring the disease such as subarachnoid hemorrhage which use EIT technique for early diagnoses. Furthermore exploring the primary regularity of the electrical impedance changes in the animal models of subarachnoid hemorrhage will be helpful for the estimation of illness and regulate the treatments for patients in time.Objectives Early diagnosis of non-traumatic subarachnoid hemorrhage can obviously decrease the mortality and improve the outcome of patient who suffered from the incidence. This study investigated the ability of electrical impedance tomography(EIT) system to detect early subarachnoid hemorrhage(SAH).To explore the primary regularity of the electrical impedance changes in the animal models of subarachnoid hemorrhage as well as the possible manchnism of this regularity.Methods 15 healthy piglets, male or female, weight is 13.21±0.81 kg for each one. 10 piglets were randomly divided into experimental groups and 5 piglets in a control group. After anesthesia dogs were fixed on vulnerating-bench. The experimental subarachnoid hemorrhage models of piglets were introduced by one-time injection of fresh autologous blood into the cisterna magna (CM). The piglets of control group were introduced by one-time injection of saline into the (CM). We could observe changes of the two-dimensional imaging with EIT system which operate the continual monitoring to the models.Results Among the 15 included animals, 2 piglets in the operation group were dropped out, because of death in the experimental process, thus, totally 8 piglets in experimental group and 5 piglets in control group were involved in the result analysis. The monitoring images of experimental group displayed that in the forepart of the injection, resistivity configuration decreased at the anterior region of the head as well as the posterior of that. At the time of finishing injection, the resistivity configuration reach the negative max value. After injection, resistivity configuration at the anterior region of the head have gradually come back. But the resistivity configuration at the posterior region of the head have increased persistently. The monitoring images of control group displayed that in the forepart of the injection, resistivity configuration decreased at the anterior region of the head as well as the posterior of that. During the injection, resistivity configuration of negative maximum reach a plateau phase. After injection, resistivity configuration at the anterior region of the head have gradually come back and the resistivity configuration at the whole region of the head have increased persistently, but the level was lower or shorter than that of control group. Although the images of monitoring on experimental and control group were similar, the curve of negative max reconstruction results display that the chang trend were significantly different.Conclusion Although the configuration of human head is so complex which limited the application of EIT on the head, it has certain sensitivity in the diagnosis of SAH. Although the detail of the changing rule is still not clear, it might have a widely application in early diagnosis and assistant treatment in clinical.