Development and performance evaluation of the first model of 4D CT-scanner
Development and performance evaluation of the first model of 4D CT-scanner
复制标题
第一个 4D CT 扫描仪模型的开发和性能评估
DOI：
10.1109/nssmic.2002.1239677
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
M. Kusakabe
中科院分区：
文献类型：
--
作者：
M. Endo;S. Mori;T. Tsunoo;S. Kandatsu;S. Tanada;H. Aradate;Y. Saito;H. Miyazaki;K. Satoh;S. Matsusita;M. Kusakabe
四维CT是一种运动器官的动态体积成像系统，其成像质量可与常规CT相媲美，是用连续高速锥束CT实现的。为了实现四维CT，我们在现有CT技术的基础上开发了一种新型的二维探测器，并将其安装在最先进的CT扫描仪的龙门架上。在本报告中，我们描述了第一个型号的四维CT扫描仪的设计和性能评估结果。4DCT扫描仪的X射线探测器是一种离散的像素探测器，其中的像素数据由独立的探测器元件测量。单元数为912(通道)/SPL次/256(段)，单元大小约为1 mm/SPL次/1 mm。数据采样率为900视(帧)/秒，A/D转换器的动态范围为16位。龙门的旋转速度为1.0秒/转。龙门转动和静止部分之间的数据传输系统由激光二极管和光电二极管对组成，实现了5Gbps的净传输速度。512/SPL次/512/SPL次/256体素的体数据在微处理器上并行使用FDK算法进行重建。用静止体模在单次旋转中评价图像的噪声、均匀性和空间分辨率等特征。通过扩展CT剂量指数(CTDI)的标准测量方法来测量对象的照射剂量。几名志愿者接受了扫描，以探索临床潜力。对于四维CT扫描仪，静止物体的图像特征和曝光剂量与常规CT几乎相同。对静止物体的各向同性分辨率小于0.5 mm。
4D CT is a dynamic volume imaging system of moving organs with an image quality comparable to conventional CT, and is realized with continuous and high-speed cone-beam CT. In order to realize 4D CT, we have developed a novel 2D detector on the basis of the present CT technology, and mounted it on the gantry frame of the state-of-the-art CT-scanner. In the present report we describe the design and the results of performance evaluation of the first model of 4D CT-scanner. The X-ray detector for the 4D CT-scanner is a discrete pixel detector in which pixel data are measured by an independent detector element. The numbers of elements are 912 (channels) /spl times/ 256 (segments) and the element size is approximately 1 mm /spl times/ 1 mm. The data sampling rate is 900 views(frames)/sec, and the dynamic range of the A/D converter is 16 bits. The rotation speed of the gantry is 1.0 sec/rotation. The data transfer system between rotating and stationary parts in the gantry consists of a laser diode and photodiode pairs, and achieves net transfer speed of 5 Gbps. Volume data of 512/spl times/512/spl times/256 voxels are reconstructed with FDK algorithm by parallel use of microprocessors. The image characteristics such as noise, uniformity and spatial resolution were evaluated with stationary phantoms in a single rotation. Exposure dose to an object was measured with an extension of the standard measurement method of the CT dose index (CTDI). Several volunteers were scanned to explore clinical potentials. For the 4D CT-scanner, the image characteristics of stationary objects and exposure dose were almost the same to that of conventional CT. An isotropic resolving power of less than 0.5 mm was achieved for the stationary object.