论文标题
使用主调制器和双层检测器的单发定量X射线成像
Single-Shot Quantitative X-ray Imaging Using a Primary Modulator and Dual-Layer Detector
论文作者
论文摘要
目的：传统的X射线成像和荧光镜检查在定量上存在局限性，包括散射，束硬化和重叠的组织。在这项工作中，我们通过将使用主调制器（PM）和双层（DL）检测器结合使用单摄像定量成像（SSQI），该检测器可以单张镜头中启用无运动双能（DE）成像与散射校正。 方法：SSQI算法允许使用PM编码中的四个子测量值同时恢复两个特定于材料的图像和两个散射图像。为了进行验证，我们在桌面系统上设置了SSQI，并成像具有已知厚度的丙烯酸和铜板，用我们的SSQI算法估算了散射，并比较了两种材料与地面真理的不同组合的材料分解（MD）。其次，我们成像了拟人动脉中包含对比的拟人化胸部幻影，并与有或没有SSQI的MD进行了比较。最后，为了评估动态应用中的SSQI，我们构建了一个流动幻影，该流量启用了碘对比度的动态成像。 结果：SSQI估计的根平方误差（RMSE）的丙烯酸为0.13 cm，铜为0.04 mm。对于拟人化幻影，直接MD导致对比度和软组织的解释不正确，而SSQI成功区分了它们，并在特定于材料的图像中将RMSE降低了38％至92％。对于流幻象，SSQI能够执行准确的动态定量成像，从而将对比度与背景分开。 结论：我们证明了SSQI对可靠的定量X射线成像的潜力。 SSQI的简单性可以使其广泛采用，包括X射线照相和动态成像，例如实时图像引导和锥形束CT。
Purpose: Conventional x-ray imaging and fluoroscopy have limitations in quantitation due to several challenges, including scatter, beam hardening, and overlapping tissues. In this work, we propose single-shot quantitative imaging (SSQI) by combining the use of a primary modulator (PM) and dual-layer (DL) detector, which enables motion-free dual-energy (DE) imaging with scatter correction in a single shot. Methods: The SSQI algorithm allows simultaneous recovery of two material-specific images and two scatter images using four sub-measurements from the PM encoding. For validation, we set up SSQI on our tabletop system and imaged acrylic and copper slabs with known thicknesses, estimated scatter with our SSQI algorithm, and compared the material decomposition (MD) for different combinations of the two materials with ground truth. Second, we imaged an anthropomorphic chest phantom containing contrast in the coronary arteries and compared the MD with and without SSQI. Lastly, to evaluate SSQI in dynamic applications, we constructed a flow phantom that enabled dynamic imaging of iodine contrast. Results: The root mean squared error (RMSE) of SSQI estimation was 0.13 cm for acrylic and 0.04 mm for copper. For the anthropomorphic phantom, direct MD resulted in incorrect interpretation of contrast and soft tissue, while SSQI successfully distinguished them and reduced RMSE in material-specific images by 38% to 92%. For the flow phantom, SSQI was able to perform accurate dynamic quantitative imaging, separating contrast from the background. Conclusions: We demonstrated the potential of SSQI for robust quantitative x-ray imaging. The simplicity of SSQI may enable its widespread adoption, including radiography and dynamic imaging such as real-time image guidance and cone-beam CT.
