| 直线加速器机载锥形束CT图像散射的修正方法 |
| |
| 引用本文： | 梁晓坤,牛田野,周勤煊,张怀岺.直线加速器机载锥形束CT图像散射的修正方法[J].中国医学影像技术,2016,32(4):619-622. |
| |
| 作者姓名： | 梁晓坤 牛田野 周勤煊 张怀岺 |
| |
| 作者单位： | 广东医学院信息工程学院, 广东 东莞 523808,浙江大学转化医学研究院, 浙江 杭州 310016;浙江大学医学院附属邵逸夫医院放疗科, 浙江 杭州 310016,浙江大学医学院附属邵逸夫医院放疗科, 浙江 杭州 310016,广东医学院信息工程学院, 广东 东莞 523808 |
| |
| 基金项目： | 广东省创新研究团队项目(2011S013). |
| |
| 摘 要： | 目的 对直线加速器机载锥形束CT(CBCT)散射修正方法进行研究.方法 在CBCT射线源前放置一个"指交叉"形的阻挡光栅,对Catphan 504模体进行扫描,分别获得CBCT图像和扇形束CT图像.利用基于阈值的图像分割算法跟踪机架旋转过程中阻挡光栅在CBCT图像中的位置,提取散射样本后利用插值法估计散射信号分布,采用改进的半扇扫描重建算法重建散射修正后的图像.结果 散射修正后的Catphan 504模体图像与扇形束CT重建的图像接近.与散射修正前比较,散射修正后CT值误差从100.86 HU下降到15.74 HU,散射修正后低对比度分辨力平均提高1.37倍.结论 基于阈值的图像分割算法准确跟踪阻挡光栅的位置,在铅片区域可采集散射信号,其余区域可通过改进的半扇扫描算法完成单次扫描的图像重建.
|
| 关 键 词： | 散射修正 锥形束 体层摄影术 X线计算机 射束阻挡器 |
| 收稿时间： | 2015/11/12 0:00:00 |
| 修稿时间： | 2016/1/21 0:00:00 |
Scatter correction of linear accelerator cone-beam CT image |
| |
| LIANG Xiaokun,NIU Tianye,ZHOU Qinxuan and ZHANG Huailing.Scatter correction of linear accelerator cone-beam CT image[J].Chinese Journal of Medical Imaging Technology,2016,32(4):619-622. |
| |
| Authors: | LIANG Xiaokun NIU Tianye ZHOU Qinxuan and ZHANG Huailing |
| |
| Institution: | School of Information Engineering, Guangdong Medical College, Dongguan 523808, China,Institute of Translational Medicine, Zhejiang University, Hangzhou 310016, China;Department of Radiation Oncology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China,Department of Radiation Oncology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China and School of Information Engineering, Guangdong Medical College, Dongguan 523808, China |
| |
| Abstract: | Objective To study the scatter correction of linear accelerator cone-beam CT (CBCT) image. Methods A "crossing-finger" X-ray grid was placed on the front of CBCT X-ray source. Catphan 504 Phantom was scanned, and CBCT images and fan-beam CT images were acquired. The threshold-based segmentation algorithm was adopted to track the cone-beam during the rotation of gantry. After acquiring the scatter sample, the distribution of scatter signal was estimated by interpolation method. Finally, scatter-corrected CT images was reestablished using modified half-fan scan reconstruction algorithm. Results After scatter correction, the CBCT images of Catphan 504 Phantom was approaching to fan-beam CT image. Compared to the CBCT images before scatter correction, the reconstruction error was reduced from 100.86 HU to 15.74 HU after scatter correction, and low contrast resolution was improved 1.37 times. Conclusion The threshold-based segmentation algorithm can track the beam blocker exactly. The scatter signal can be aquired in lead sheet area, while other area can be reconstruction after single scan by modified half-fan reconstruction algorithm. |
| |
| Keywords: | Scatter correction Cone beam Tomography X-ray computed Beam block |
|
| 点击此处可从《中国医学影像技术》浏览原始摘要信息 |
| 点击此处可从《中国医学影像技术》下载免费的PDF全文 |
|
