High-Spatial-Resolution Medical-Imaging System Using a HARPICON Camera Coupled with a Fluorescent Screen.
High-Spatial-Resolution Medical-Imaging System Using a HARPICON Camera Coupled with a Fluorescent Screen.
复制标题
使用 HARPICON 相机和荧光屏的高空间分辨率医学成像系统。
DOI：
10.1107/s0909049596001859
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发表时间：
1996
影响因子：
2.5
通讯作者：
M. Akisada
中科院分区：
文献类型：
--
作者：
K. Umetani;H. Ueki;K. Ueda;T. Hirai;T. Takeda;T. Doi;J. Wu;Y. Itai;M. Akisada
高灵敏度的HARPICON相机被开发用于使用荧光屏的医学X射线成像。它是一种雪崩倍增型摄像管，灵敏度是传统摄像管的32倍。该相机还具有比传统的医学成像相机更宽的动态范围，因为获得了2.3 μ A的最大输出信号电流，并且在高照明强度区域中，光电流与照明强度不成比例。荧光屏是用于医学检查中的射线照相屏-胶片组合的类型的增感屏。使用f/0.65的耦合透镜将屏幕上的X射线图像聚焦在拾取管的光电导层上。在光子工厂使用单色X射线进行实验。在照相机的525扫描线模式下拍摄空间分辨率测试图的图像。在50 x 50 mm的X射线输入场观察5线对mm（-1）（空间分辨率为100 μ m）的图表图案。在将造影剂注射到动脉中后，以60图像s（-1）的帧速率获得12 kg狗心脏的实时数字图像。图像以512 x 480像素的数字格式存储，12位像素（-1）。使用能量高于碘K边缘的X射线，在冠状动脉造影中获得冠状动脉的高空间分辨率和高对比度图像;图像质量与传统的选择性冠状动脉造影相当。
A high-sensitivity HARPICON camera was developed for medical X-ray imaging using a fluorescent screen. It is an avalanche-multiplication-type image pick-up tube and is 32 times more sensitive than conventional tubes. The camera also has a wider dynamic range than conventional medical-imaging cameras because a maximum output signal current of 2.3 muA is obtained and, in high-illumination-intensity regions, photocurrent is not proportional to illumination intensity. The fluorescent screen is an intensifying screen of the type used for radiographic screen-film combinations in medical examination. An X-ray image on the screen is focused on the photoconductive layer of the pick-up tube using a coupling lens with f/0.65. Experiments were performed using monochromated X-rays at the Photon Factory. An image of a spatial resolution test chart was taken in a 525 scanning-line mode of the camera. The chart pattern of 5 line-pairs mm(-1 )(spatial resolution of 100 mum) was observed at an X-ray input field of 50 x 50 mm. Real-time digital images of the heart of a 12 kg dog were obtained at a frame rate of 60 images s(-1) after injection of a contrast medium into an artery. The images were stored in digital format at 512 x 480 pixels with 12 bits pixel(-1). High-spatial-resolution and high-contrast images of coronary arteries were obtained in aortography using X-rays with energy above that of the iodine K edge; the image quality was comparable with that of conventional selective coronary angiography.