目的探讨1.5T磁共振三维快速自旋回波成像(3D sampling perfection with application optimized contrasts by using different flip angle evolutions,3D-SPACE)与多回波融合成像(multiple echo data image combination,3D-MEDIC)序列...目的探讨1.5T磁共振三维快速自旋回波成像(3D sampling perfection with application optimized contrasts by using different flip angle evolutions,3D-SPACE)与多回波融合成像(multiple echo data image combination,3D-MEDIC)序列对正常人腰骶丛神经的显示。方法 31例无症状正常志愿者行MRI检查,包括常规腰椎MRI、3D-SPACE及MEDIC序列扫描,原始图像传入后处理工作站行多平面图像重组。结合原始及重组图像,比较3D-SPACE及MEDIC序列图像腰骶丛神经根的信噪比及对神经的显示评分。结果 3D-MEDIC序列显示神经根的信噪比高于3D-SPACE序列(分别为70.15±24.03及28.78±7.12,P=0.000)。3D-MEDIC序列对腰骶丛的显示评分高于3D-SPACE序列(P=0.000)。结论1.5T磁共振腰骶丛神经显像中,3D-MEDIC序列优于3D-SPACE序列,可清晰显示神经根走行,是常规腰椎MRI的重要补充。展开更多
This paper takes some investigations on generalized topological spaces with some μ- separations. Some characterizations of μTi-spaces for i = 0, 1, 2, 3, 4, μTn-spaces and μR0-spaces are obtained and some relation...This paper takes some investigations on generalized topological spaces with some μ- separations. Some characterizations of μTi-spaces for i = 0, 1, 2, 3, 4, μTn-spaces and μR0-spaces are obtained and some relations among these spaces are established.展开更多
In Newton’s classical physics, space and time are treated as absolute, independent quantities and can be discussed separately. In Special Relativity, Einstein proved that space and time are relative and dependent and...In Newton’s classical physics, space and time are treated as absolute, independent quantities and can be discussed separately. In Special Relativity, Einstein proved that space and time are relative and dependent and therefore must not be treated separately. Minkowski adopted four-dimensional space-time frames (4-d s-t frames), which indirectly revealed the dependency of space and time with the addition of a constraint for an event interval. We are not able to visualize 4-d s-t frames. Since space and time are inseparable, three-dimensional space-time frames (3-d s-t frames) can be constructed by embedding time into space to directly show the interdependency of space and time. Time contraction and length contraction can also be depicted graphically using 3-d s-t frames. We have much better understanding reality of space and time in 3-d s-t frames. This will lead to Contextual Reality for better understanding the universe.展开更多
文摘目的探讨1.5T磁共振三维快速自旋回波成像(3D sampling perfection with application optimized contrasts by using different flip angle evolutions,3D-SPACE)与多回波融合成像(multiple echo data image combination,3D-MEDIC)序列对正常人腰骶丛神经的显示。方法 31例无症状正常志愿者行MRI检查,包括常规腰椎MRI、3D-SPACE及MEDIC序列扫描,原始图像传入后处理工作站行多平面图像重组。结合原始及重组图像,比较3D-SPACE及MEDIC序列图像腰骶丛神经根的信噪比及对神经的显示评分。结果 3D-MEDIC序列显示神经根的信噪比高于3D-SPACE序列(分别为70.15±24.03及28.78±7.12,P=0.000)。3D-MEDIC序列对腰骶丛的显示评分高于3D-SPACE序列(P=0.000)。结论1.5T磁共振腰骶丛神经显像中,3D-MEDIC序列优于3D-SPACE序列,可清晰显示神经根走行,是常规腰椎MRI的重要补充。
基金Supported by the National Natural Science Foundation of China(10971185)
文摘This paper takes some investigations on generalized topological spaces with some μ- separations. Some characterizations of μTi-spaces for i = 0, 1, 2, 3, 4, μTn-spaces and μR0-spaces are obtained and some relations among these spaces are established.
文摘In Newton’s classical physics, space and time are treated as absolute, independent quantities and can be discussed separately. In Special Relativity, Einstein proved that space and time are relative and dependent and therefore must not be treated separately. Minkowski adopted four-dimensional space-time frames (4-d s-t frames), which indirectly revealed the dependency of space and time with the addition of a constraint for an event interval. We are not able to visualize 4-d s-t frames. Since space and time are inseparable, three-dimensional space-time frames (3-d s-t frames) can be constructed by embedding time into space to directly show the interdependency of space and time. Time contraction and length contraction can also be depicted graphically using 3-d s-t frames. We have much better understanding reality of space and time in 3-d s-t frames. This will lead to Contextual Reality for better understanding the universe.
