说明：  该代码用Matlab实现模拟CT投影数据采集、反投影重建，包括以下内容： 1. 用Matlab读取和显示一幅shepp-logan体模图像； 2. 选定扫描起始角度和间隔； 3. 进行radon变换，显示投影数据； 4. 进行irandon变换，显示反投影重建图像； 5. 进行fanbeam变换，显示数据； 6. 进行ifanbeam变换，显示反投影重建图象。
(The code using Matlab simulation CT projection data acquisition, back projection reconstruction, including the following: 1. Matlab read and display a shepp-logan phantom image 2. Select the scanning start angle and interval 3. Conduct radon transform projection display data 4. Make irandon transform backprojection image display 5. Make fanbeam conversion, display data 6. Make ifanbeam conversion, display reverse projection image reconstruction.)