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1.发明授权Apparatus for minimising the effect of concentrated high density material outside a small scan circle in computed tomography 失效用于最小化浓度高密度材料在计算机图像中的小扫描圆周的影响的装置
公开(公告)号：EP0030144B1
公开(公告)日：1986-09-24
申请号：EP80304291.0
申请日：1980-11-28
IPC分类号： G06F15/42
CPC分类号： A61B6/483 , A61B6/032 , A61B6/4275 , G06T11/005 , G06T2211/421 , Y10S378/901
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2.发明公开Method of preprocessing truncated intensity projection values in computed tomography 失效在计算机图像中预处理截断强度投影值的方法
公开(公告)号：EP0030143A3
公开(公告)日：1981-12-23
申请号：EP80304290
申请日：1980-11-28
IPC分类号： G06F15/20
CPC分类号： G06T11/005 , G06T2211/421 , G06T2211/432 , Y10S128/922 , Y10S378/901
摘要： A method of preprocessing incomplete or truncated projections obtained from high resolution CT scanning of a small scan circle corresponding to a limited region of interest within the scanned object. An air calibration is performed to obtain a set of air values. The intensity values obtained during the partial area scan are subtracted from the air values to convert .the intensity values to attenuation values. The approximate slope at either end of the truncated projection is then calculated. Based on the attenuation values and the slope the necessary extrapolation of the truncated projection is performed to complete the projection. No measurements, ionizing or otherwise, are required from the region outside of the small scan circle. The completed projection is ready for conventional reconstruction techniques involving convolution and backprojection.
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3.发明公开Apparatus for minimising the effect of concentrated high density material outside a small scan circle in computed tomography 失效装置用于最小化在计算机断层摄影中的小扫描圆之外浓缩高密度材料的效果。
公开(公告)号：EP0030144A2
公开(公告)日：1981-06-10
申请号：EP80304291.0
申请日：1980-11-28
IPC分类号： G06F15/42
CPC分类号： A61B6/483 , A61B6/032 , A61B6/4275 , G06T11/005 , G06T2211/421 , Y10S378/901
摘要： A method and apparatus for minimizing a streaking effect found in reconstructed images obtained from high resolution CT scanning of a small scan circle that corresponds to a limited region of interest, such as portions of the spinal cord of a patient, particularly in scans that include concentrated high density material, such as bone, situated outside the small scan circle. The approximate range of view angles that will project bone from outside the limited region of interest is determined. Detectors corresponding to the determined region are selected out. The projection data acquired by the selected detectors is filtered. The filtering is accomplished by convolving the projection data with a preselected filter function or in machine implemented form by passing the electrical signal representing the projection data through a low pass filter.
摘要翻译： 一种用于最小化在从一个小的扫描圆的高分辨率CT扫描获得的重构图像中找到一个条纹效果确实对应于感兴趣,:有限区域如患者的脊髓的部分，例如，特别是在扫描的方法和设备也包括浓 高密度材料，颜色：如骨，位于小扫描圆外。 的视图的大致范围内从外部感兴趣的有限区域是确定性的开采角thatwill项目骨。 检测器对应于所述确定的开采区域被选择出来。 由所选择的检测器获取的投影数据进行滤波。 所述滤波由通过使表示通过低通滤波器的投影数据的电信号进行卷积与预选的filterFunction或在机器实现的形式的投影数据来实现的。
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4.发明授权Apparatus for preprocessing truncated intensity projection values in computed tomography 失效在计算机图像中预处理截断强度投影值的装置
公开(公告)号：EP0030143B1
公开(公告)日：1986-09-24
申请号：EP80304290.2
申请日：1980-11-28
IPC分类号： G06F15/42
CPC分类号： G06T11/005 , G06T2211/421 , G06T2211/432 , Y10S128/922 , Y10S378/901
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5.发明公开Method and apparatus for minimising the effect of concentrated high density material outside a small scan circle in computed tomography 失效用于最小化浓缩高密度材料在计算机图形中的小扫描圆周的影响的方法和装置
公开(公告)号：EP0030144A3
公开(公告)日：1981-12-02
申请号：EP80304291
申请日：1980-11-28
IPC分类号： G06F15/20
CPC分类号： A61B6/483 , A61B6/032 , A61B6/4275 , G06T11/005 , G06T2211/421 , Y10S378/901
摘要： A method and apparatus for minimizing a streaking effect found in reconstructed images obtained from high resolution CT scanning of a small scan circle that corresponds to a limited region of interest, such as portions of the spinal cord of a patient, particularly in scans that include concentrated high density material, such as bone, situated outside the small scan circle. The approximate range of view angles that will project bone from outside the limited region of interest is determined. Detectors corresponding to the determined region are selected out. The projection data acquired by the selected detectors is filtered. The filtering is accomplished by convolving the projection data with a preselected filter function or in machine implemented form by passing the electrical signal representing the projection data through a low pass filter.
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6.发明公开Apparatus for preprocessing truncated intensity projection values in computed tomography 失效用于在所述计算机断层摄影预处理不完全强度投影值。
公开(公告)号：EP0030143A2
公开(公告)日：1981-06-10
申请号：EP80304290.2
申请日：1980-11-28
IPC分类号： G06F15/42
CPC分类号： G06T11/005 , G06T2211/421 , G06T2211/432 , Y10S128/922 , Y10S378/901
摘要： A method of preprocessing incomplete or truncated projections obtained from high resolution CT scanning of a small scan circle corresponding to a limited region of interest within the scanned object. An air calibration is performed to obtain a set of air values. The intensity values obtained during the partial area scan are subtracted from the air values to convert .the intensity values to attenuation values. The approximate slope at either end of the truncated projection is then calculated. Based on the attenuation values and the slope the necessary extrapolation of the truncated projection is performed to complete the projection. No measurements, ionizing or otherwise, are required from the region outside of the small scan circle.
The completed projection is ready for conventional reconstruction techniques involving convolution and backprojection.
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