Crump Institute for Molecular Imaging, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
Phys Med Biol. 2010 Feb 21;55(4):1141-55. doi: 10.1088/0031-9155/55/4/016. Epub 2010 Jan 28.
Dual-energy x-ray computed tomography (DECT) has the capability to decompose attenuation coefficients using two basis functions and has proved its potential in reducing beam-hardening artifacts from reconstructed images. The method typically involves two successive scans with different x-ray tube voltage settings. This work proposes an approach to dual-energy imaging through x-ray beam filtration that requires only one scan and a single tube voltage setting. It has been implemented in a preclinical microCT tomograph with minor modifications. Retrofitting of the microCT scanner involved the addition of an automated filter wheel and modifications to the acquisition and reconstruction software. Results show that beam-hardening artifacts are reduced to noise level. Acquisition of a mu-Compton image is well suited for attenuation-correction of PET images while dynamic energy selection (4D viewing) offers flexibility in image viewing by adjusting contrast and noise levels to suit the task at hand. All dual-energy and single energy reference scans were acquired at the same soft tissue dose level of 50 mGy.
双能 X 射线计算机断层扫描（DECT）具有使用两个基函数分解衰减系数的能力，并已证明其在减少重建图像中的束硬化伪影方面具有潜力。该方法通常涉及两次具有不同 X 射线管电压设置的连续扫描。这项工作提出了一种通过 X 射线束过滤进行双能成像的方法，该方法仅需要一次扫描和一个单管电压设置。它已经在具有微小修改的临床前微计算机断层扫描体层摄影仪中实现。微计算机断层扫描扫描仪的改装包括添加自动滤光片轮以及对采集和重建软件进行修改。结果表明，束硬化伪影降低到噪声水平。μ-Compton 图像的采集非常适合正电子发射断层扫描图像的衰减校正，而动态能量选择（4D 观察）则通过调整对比度和噪声水平以适应手头的任务，为图像观察提供了灵活性。所有双能和单能参考扫描均在相同的软组织剂量水平（50 mGy）下采集。
