ABSTRACT
In order to accurately implant the brain electrodes of carp robot for positioning and navigation, the three-dimensional model of brain structure and brain electrodes is to be proposed in the study. In this study, the tungsten electrodes were implanted into the cerebellum of a carp with the aid of brain stereotaxic instrument. The brain motor areas were found and their three-dimensional coordinate values were obtained by the aquatic electricity stimulation experiments and the underwater control experiments. The carp brain and the brain electrodes were imaged by 3.0 T magnetic resonance imaging instrument, and the three-dimensional reconstruction of carp brain and brain electrodes was carried out by the 3D-DOCTOR software and the Mimics software. The results showed that the brain motor areas and their coordinate values were accurate. The relative spatial position relationships between brain electrodes and brain tissue, brain tissue and skull surface could be observed by the three-dimensional reconstruction map of brain tissue and brain electrodes which reconstructed the three-dimensional structure of brain. The anatomical position of the three-dimensional reconstructed brain tissue in magnetic resonance image and the relationship between brain tissue and skull surface could be observed through the three-dimensional reconstruction comprehensive display map of brain tissue. The three-dimensional reconstruction model in this study can provide a navigation tool for brain electrodes implantation.
Subject(s)
Animals , Brain/diagnostic imaging , Carps , Electrodes , Electrodes, Implanted , Imaging, Three-Dimensional , Magnetic Resonance ImagingABSTRACT
To solve the problem of precise positioning of carp brain tissue coordinates, it is proposed in this paper for a method for transforming the coordinates of magnetic resonance imaging of carp brain tissue into the coordinates of electrode implantation using a brain stereotaxic apparatus. In this study, the 3.0T magnetic resonance imaging instrument was used to scan the carp brain. We independently established the three-dimensional positioning coordinate system of the brain, the three-dimensional coordinate assistance system of skull surface and the three-dimensional coordinate assistance system in brain tissue. After two coordinate transformations, the magnetic resonance image coordinates of the brain electrodes implantation sites were converted into the three-dimensional stereotactic coordinate system to guide the electrodes implantation. The experimental groups were divided into two groups, A and B. Group A was the group of magnetic resonance imaging apparatus combining with the brain stereotaxic apparatus, and group B was the group of brain atlas combining with the brain stereotaxic apparatus. Each group had 20 tails of carps ( = 20). This two methods were used to implant the electrodes into the cerebellar motor area. The underwater experiments of the carp robots were carried out to test the two methods. The results showed that the accuracy of the implanted electrodes were 90% in group A and 60% in group B. The success rate of group A was significantly higher than that of group B ( < 0.05). Therefore, the new method in this paper can accurately determine the coordinates of carp brain tissue.
ABSTRACT
Objective To compare the difference of echocardiography and magnetic resonance imaging (MRI) in measurement of cardiac function in patients with dilated cardiomyopathy (DCM).Methods Totally 41 patients with DCM underwent echocardiography and MRI to measure cardiac function,the parameters included left ventricular end-diastolic volume (LVEDV),end systolic volume (LVESV),left ventricular ejection fraction (LVEF) and stroke volume (SV).The vertical long axis (VLA),horizontal long axis (HLA) and short axis (SA) of heart were measured by echocardiography.The differences of echocardiography and MRI were compared by linear regression and linear correlation.Results ①The value of LVEDV and LVESV obtained by the two methods:the value of LVEDV [(262.6 ± 117.0) ml] and LVESV [(196.4 ± 109.8) ml] obtained by MRI were higher than those of echocardiography [(211.4 ± 90.6),(216.5 ± 71.5),(219.1 ± 80.1) ml;(153.3 ± 76.1),(153.9 ± 54.1),(157.0 ± 61.1) ml,all P ＜ 0.05].②The value of SV and LVEF obtained by the two methods:the value of SV[(66.2 ± 21.3) ml] obtained by MRI was higher than that of echocardiography VLA [(58.1 ± 14.4) ml,P ＜ 0.05].The value of LVEF [(25.2 ±7.2)％] obtained by MRI was lower than those of echocardiography HLA and echocardiography SA [(28.9 ± 6.1)％,(28.3 ± 6.1)％,all P ＜ 0.05].③The value of LVEDV and LVESV obtained by echocardiography SA were associated with those obtained by MRI (r =0.785,0.653,all P ＜ 0.05).The value of LVEF obtained by echocardiography VLA was associated with it obtained by MRI (r =0.690,P ＜ 0.05).The value of SV obtained by echocardiography HLA and echocardiography SA were associated with those obtained by MRI (r =0.734,0.701,all P ＜ 0.05).Conclusion There are differences in accuracy and reliability using echocardiography and MRI when measuring dilated cardiomyopathy heart function,which must be treated differently.