Liu Leening P, Pasyar Pouyan, Liu Fang, Cao Quy, Sandvold Olivia F, Rybertt Martin V, Sahbaee Pooyan, Shinohara Russell T, Litt Harold I, Noël Peter B
Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.
Eur Radiol. 2024 Dec 19. doi: 10.1007/s00330-024-11244-y.
Among the advancements in computed tomography (CT) technology, photon-counting computed tomography (PCCT) stands out as a significant innovation, providing superior spectral imaging capabilities while simultaneously reducing radiation exposure. Its long-term stability is important for clinical care, especially longitudinal studies, but is currently unknown. This study sets out to comprehensively analyze the long-term stability of a first-generation clinical PCCT scanner.
Over a 2-year period, from November 2021 to November 2023, we conducted weekly identical experiments utilizing the same multi-energy CT protocol. Throughout this period, notable software and hardware modifications were meticulously recorded. Various tissue-mimicking inserts were scanned weekly to rigorously assess the stability of Hounsfield Units (HU) and image noise in Virtual Monochromatic Images (VMIs) and iodine density maps.
Spectral results consistently demonstrated the quantitative stability of PCCT. VMIs exhibited stable HU values, such as variation in relative error for VMI 70 keV measuring 0.11% and 0.30% for single-source and dual-source modes, respectively. Similarly, noise levels remained stable with slight fluctuations linked to software changes for VMI 40 and 70 keV that corresponded to changes of 8 and 1 HU, respectively. Furthermore, iodine density quantification maintained stability and showed significant improvement with software and hardware changes, especially in dual-source mode with nominal errors decreasing from 1.44 to 0.03 mg/mL.
This study provides the first long-term reproducibility assessment of quantitative PCCT imaging, highlighting its potential for the clinical arena.
Question Photon-counting CT (PCCT) provides critical spectral imaging for improved diagnostic accuracy, but its long-term quantitative stability over time is still unknown. Findings The clinical PCCT system demonstrated stable Hounsfield Units (HU) and image noise over 2 years, ensuring reliable quantitative imaging and improving diagnostic accuracy. Clinical relevance This study showcased the exceptional value of PCCT in diagnostic radiology, particularly for its application in longitudinal studies.
在计算机断层扫描（CT）技术的诸多进展中，光子计数计算机断层扫描（PCCT）是一项重大创新，它在提供卓越光谱成像能力的同时，还能降低辐射剂量。其长期稳定性对临床护理至关重要，尤其是在纵向研究中，但目前尚不清楚。本研究旨在全面分析第一代临床PCCT扫描仪的长期稳定性。
在2021年11月至2023年11月的两年时间里，我们每周使用相同的多能量CT协议进行相同的实验。在此期间，详细记录了显著的软件和硬件修改情况。每周扫描各种仿组织插入物，以严格评估虚拟单色图像（VMI）中的亨氏单位（HU）和图像噪声以及碘密度图的稳定性。
光谱结果始终证明了PCCT的定量稳定性。VMI显示出稳定的HU值，例如，对于VMI 70 keV，单源和双源模式下相对误差的变化分别为0.11%和0.30%。同样，噪声水平保持稳定，与VMI 40和70 keV的软件变化相关的轻微波动分别对应8和1 HU的变化。此外，碘密度定量保持稳定，并且随着软件和硬件的变化有显著改善，特别是在双源模式下，标称误差从1.44降至0.03 mg/mL。
本研究提供了对定量PCCT成像的首次长期可重复性评估，突出了其在临床领域的潜力。
问题 光子计数CT（PCCT）为提高诊断准确性提供了关键的光谱成像，但其随时间的长期定量稳定性仍然未知。发现 临床PCCT系统在两年内显示出稳定的亨氏单位（HU）和图像噪声，确保了可靠的定量成像并提高了诊断准确性。临床意义 本研究展示了PCCT在诊断放射学中的非凡价值，特别是其在纵向研究中的应用。
