Abstract The dual-energy (DE) technique is useful in chest radiography because it can separate anatomical structures, such as bone and soft tissue. The standard log subtraction, simple smoothing of the high-energy image, anti-correlated noise reduction, and general linear noise reduction algorithms have been used as conventional DE techniques to separate bone and soft tissue. However, conventional DE techniques cannot accurately decompose anatomical structures because these techniques are based on the assumption that X-ray imaging proceeds in a linear relationship. This relationship can cause quantum noise, as well as anatomical loss of normal tissue and difficulty in detecting lesions. In this study, we propose a non-linear DE technique that requires the calculation of the coefficient in advance by using a calibration phantom. The calibration phantom is composed of aluminium and PMMA to calculate non-linear coefficients using the quadratic fitting model for soft tissue and bone. The results demonstrated that the non-linear DE technique exhibited a higher contrast-to-noise ratio, signal-to-noise ratio, and figure of merit at 60/70 kVp and 130 kVp. In addition, it demonstrated better performance and image quality than conventional DE techniques in terms of material decomposition capability. In conclusion, diagnostic accuracy in chest radiography is expected to increase through the non-linear DE technique.

中文翻译：

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一种非线性双能胸片技术的发展

摘要 双能 (DE) 技术在胸片中很有用，因为它可以分离解剖结构，如骨骼和软组织。标准对数减法、高能图像的简单平滑、反相关降噪和一般线性降噪算法已被用作传统的 DE 技术来分离骨骼和软组织。然而，传统的 DE 技术无法准确分解解剖结构，因为这些技术基于 X 射线成像以线性关系进行的假设。这种关系会导致量子噪声，以及正常组织的解剖损失和难以检测病变。在这项研究中，我们提出了一种非线性 DE 技术，该技术需要使用校准体模提前计算系数。校准体模由铝和 PMMA 组成，使用软组织和骨骼的二次拟合模型计算非线性系数。结果表明，非线性 DE 技术在 60/70 kVp 和 130 kVp 下表现出更高的对比度噪声比、信噪比和品质因数。此外，它在材料分解能力方面表现出比传统 DE 技术更好的性能和图像质量。总之，预计通过非线性 DE 技术提高胸片的诊断准确性。以及 60/70 kVp 和 130 kVp 下的品质因数。此外，它在材料分解能力方面表现出比传统 DE 技术更好的性能和图像质量。总之，预计通过非线性 DE 技术提高胸片的诊断准确性。以及 60/70 kVp 和 130 kVp 下的品质因数。此外，它在材料分解能力方面表现出比传统 DE 技术更好的性能和图像质量。总之，预计通过非线性 DE 技术提高胸片的诊断准确性。