Chair for Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, James-Franck-Str. 1, 85748, Garching, Germany.
Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.
Eur Radiol. 2018 Jul;28(7):2745-2755. doi: 10.1007/s00330-017-5238-5. Epub 2018 Feb 5.
Evaluation of imaging performance across dual-energy CT (DECT) platforms, including dual-layer CT (DLCT), rapid-kVp-switching CT (KVSCT) and dual-source CT (DSCT).
A semi-anthropomorphic abdomen phantom was imaged on these DECT systems. Scans were repeated three times for CTDIvol levels of 10 mGy, 20 mGy, 30 mGy and different fat-simulating extension rings. Over the available range of virtual-monoenergetic images (VMI), noise as well as quantitative accuracy of hounsfield units (HU) and iodine concentrations were evaluated.
For all VMI levels, HU values could be determined with high accuracy compared to theoretical values. For KVSCT and DSCT, a noise increase was observed towards lower VMI levels. A patient-size dependent increase in the uncertainty of quantitative iodine concentrations is observed for all platforms. For a medium patient size the iodine concentration root-mean-square deviation at 20 mGy is 0.17 mg/ml (DLCT), 0.30 mg/ml (KVSCT) and 0.77mg/ml (DSCT).
Noticeable performance differences are observed between investigated DECT systems. Iodine concentrations and VMI HUs are accurately determined across all DECT systems. KVSCT and DLCT deliver slightly more accurate iodine concentration values than DSCT for investigated scenarios. In DLCT, low-noise and high-image contrast at low VMI levels may help to increase diagnostic information in abdominal CT.
• Current dual-energy CT platforms provide accurate, reliable quantitative information. • Dual-energy CT cross-platform evaluation revealed noticeable performance differences between different systems. • Dual-layer CT offers constant noise levels over the complete energy range.
评估不同双能 CT（DECT）平台的成像性能，包括双层 CT（DLCT）、快速千伏切换 CT（KVSCT）和双源 CT（DSCT）。
使用半模拟人体腹部体模在这些 DECT 系统上进行成像。对 10 mGy、20 mGy 和 30 mGy 的 CTDIvol 水平以及不同的脂肪模拟延伸环重复进行了三次扫描。在可用的虚拟单能量图像（VMI）范围内，评估了噪声以及 HU 值和碘浓度的定量准确性。
与理论值相比，所有 VMI 水平的 HU 值都可以高精度地确定。对于 KVSCT 和 DSCT，随着 VMI 水平的降低，噪声增加。对于所有平台，都观察到定量碘浓度的不确定性随患者体型的增加而增加。对于中等体型的患者，在 20 mGy 时碘浓度的均方根偏差为 0.17mg/ml（DLCT）、0.30mg/ml（KVSCT）和 0.77mg/ml（DSCT）。
在所研究的 DECT 系统之间观察到明显的性能差异。在所有 DECT 系统中，碘浓度和 VMI HU 值都能准确确定。对于所研究的情况，KVSCT 和 DLCT 比 DSCT 提供了稍为准确的碘浓度值。在 DLCT 中，在低 VMI 水平下可实现低噪声和高图像对比度，这可能有助于增加腹部 CT 的诊断信息量。
当前的双能 CT 平台提供准确、可靠的定量信息。
不同系统之间的双能 CT 跨平台评估显示出明显的性能差异。
双层 CT 在整个能量范围内提供恒定的噪声水平。
