Objective: To develop a digital breast tomosynthesis (DBT) imaging system with optimizes imaging chain.
Methods: Based on 3D tomography and DBT imaging scanning, we analyzed the methods for projection data correction, geometric correction, projection enhancement, filter modulation, and image reconstruction, and established a hardware testing platform. In the experiment, the standard ACR phantom and high-resolution phantom were used to evaluate the system stability and noise level. The patient projection data of commercial equipment was used to test the effect of the imaging algorithm.
Results: In the high-resolution phantom study, the line pairs were clear without confusing artifacts in the images reconstructed with the geometric correction parameters. In ACR phantom study, the calcified foci, cysts, and fibrous structures were more clearly defined in the reconstructed images after filtering and modulation. The patient data study showed a high contrast between tissues, and the lesions were more clearly displayed in the reconstructed image.
Conclusions: This DBT imaging system can be used for mammary tomography with an image quality comparable to that of commercial DBT systems to facilitate imaging diagnosis of breast diseases.
目的: 针对数字乳腺层析成像技术(DBT)需求, 研制DBT整机系统, 实现其成像影像链的设计与优化。
方法: 基于三维X射线断层成像技术以及数字影像处理技术, 作者结合DBT成像扫描模式, 研究其投影数据校正、几何校正、投影增强、滤波调制及图像重建方法, 并搭建了硬件测试系统。实验中, 利用标准ACR体模与高分辨率体模, 对系统稳定性及噪声水平进行评估; 并采用商用设备的病人投影数据测试影像链成像算法效果。
结果: 采用几何校正参数重建高分辨率体模的图像, 线对清晰, 无混淆伪影; 滤波调制后重建的ACR体模图像中, 钙化点、囊肿、纤维结构更加清楚; 增强处理后重建的病人乳腺图像, 组织间对比度更高, 病灶显示更加清晰。
结论: 本文所介绍的DBT系统可用于乳腺断层成像, 图像质量与商用DBT系统相当, 为乳腺疾病的诊断提供重要的影像信息。
Keywords: digital breast tomosynthesis; filtered back projection; geometric correction; image chain design and optimization; projection enhancement.