Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
Med Phys. 2024 Oct;51(10):7012-7037. doi: 10.1002/mp.17322. Epub 2024 Jul 29.
Multi-energy computed tomography (MECT) offers the opportunity for advanced visualization, detection, and quantification of select elements (e.g., iodine) or materials (e.g., fat) beyond the capability of standard single-energy computed tomography (CT). However, the use of MECT requires careful consideration as substantially different hardware and software approaches have been used by manufacturers, including different sets of user-selected or hidden parameters that affect the performance and radiation dose of MECT. Another important consideration when designing MECT protocols is appreciation of the specific tasks being performed; for instance, differentiating between two different materials or quantifying a specific element. For a given task, it is imperative to consider both the radiation dose and task-specific image quality requirements. Development of a quality control (QC) program is essential to ensure the accuracy and reproducibility of these MECT applications. Although standard QC procedures have been well established for conventional single-energy CT, the substantial differences between single-energy CT and MECT in terms of system implementations, imaging protocols, and clinical tasks warrant QC tests specific to MECT. This task group was therefore charged with developing a systematic QC program designed to meet the needs of MECT applications. In this report, we review the various MECT approaches that are commercially available, including information about hardware implementation, MECT image types, image reconstruction, and postprocessing techniques that are unique to MECT. We address the requirements for MECT phantoms, review representative commercial MECT phantoms, and offer guidance regarding homemade MECT phantoms. We discuss the development of MECT protocols, which must be designed carefully with proper consideration of MECT technology, imaging task, and radiation dose. We then outline specific recommended QC tests in terms of general image quality, radiation dose, differentiation and quantification tasks, and diagnostic and therapeutic applications.
多能量计算机断层扫描（MECT）提供了高级可视化、检测和量化特定元素（如碘）或材料（如脂肪）的机会，这些是标准单能量计算机断层扫描（CT）所无法实现的。然而，在使用 MECT 时需要谨慎考虑，因为制造商使用了截然不同的硬件和软件方法，包括不同的用户选择或隐藏参数集，这些参数会影响 MECT 的性能和辐射剂量。在设计 MECT 方案时，另一个重要的考虑因素是理解正在执行的特定任务；例如，区分两种不同的材料或量化特定的元素。对于给定的任务，必须同时考虑辐射剂量和特定于任务的图像质量要求。开发质量控制（QC）程序对于确保这些 MECT 应用的准确性和可重复性至关重要。虽然针对传统单能量 CT 已经建立了标准 QC 程序，但单能量 CT 和 MECT 在系统实现、成像方案和临床任务方面存在显著差异，因此需要特定于 MECT 的 QC 测试。因此，该工作组负责开发一个系统的 QC 程序，旨在满足 MECT 应用的需求。在本报告中，我们回顾了各种商业上可用的 MECT 方法，包括有关硬件实现、MECT 图像类型、图像重建和后处理技术的信息，这些都是 MECT 所特有的。我们讨论了 MECT 体模的要求，回顾了代表性的商业 MECT 体模，并提供了有关自制 MECT 体模的指导。我们讨论了 MECT 方案的开发，这必须在充分考虑 MECT 技术、成像任务和辐射剂量的情况下精心设计。然后，我们根据一般图像质量、辐射剂量、区分和量化任务以及诊断和治疗应用，概述了具体推荐的 QC 测试。
