Phantom-based quantification of the spectral accuracy in dual-layer spectral CT for pediatric imaging at 100 kVp.
Phantom-based quantification of the spectral accuracy in dual-layer spectral CT for pediatric imaging at 100 kVp.
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DOI：
10.21037/qims-22-552
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发表时间：
2023-02-01
影响因子：
2.8
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为了确定基于探测器的双能量CT(DECT)在100kVp和宽(8 Cm)准直宽度下与儿科成像相关的剂量水平和对象大小的光谱精度。在最新一代的基于探测器的DECT系统上扫描了包含组织等效材料和不同浓度的碘插入物的光谱CT体模。两个3D打印的延长环被用来模拟不同的儿科患者大小。扫描条件分别为100和120kVp，准直宽度分别为4和8 cm，放射剂量水平逐渐降低，降至0.9mGyCTDIvol.虚拟单能、碘密度、有效原子序数和电子密度的结果被量化，并与它们在所有采集设置和体模大小下的期望值进行比较。100kVp的DECT扫描提供了高精度的光谱结果；然而，观察到碘的定量与大小有关。对于直径15 cm的中等模体构型，碘密度、有效原子序数和电子密度的测量误差分别小于0.3 mg/mL、0.2和1.8%EDwater。平均准确度与120kVP下的扫描略有不同；然而，并不是所有配置的准确率都有统计学意义。准直宽度没有实质性的影响。光谱结果对于低至0.9mGyCTDIol的辐射照射是准确可靠的。以探测器为基础的100kVp的DECT即使在极低的剂量下也可以提供高精度的按需或回溯性光谱信息，从而使其成为儿科成像的一个有吸引力的解决方案。
To determine the spectral accuracy in detector-based dual-energy CT (DECT) at 100 kVp and wide (8 cm) collimation width for dose levels and object sizes relevant to pediatric imaging. A spectral CT phantom containing tissue-equivalent materials and iodine inserts of varying concentrations was scanned on the latest generation detector-based DECT system. Two 3D-printed extension rings were used to mimic varying pediatric patient sizes. Scans were performed at 100 and 120 kVp, 4 and 8 cm collimation widths, and progressively reduced radiation dose levels, down to 0.9 mGy CTDIvol. Virtual mono-energetic, iodine density, effective atomic number, and electron density results were quantified and compared to their expected values for all acquisition settings and phantom sizes. DECT scans at 100 kVp provided highly accurate spectral results; however, a size dependence was observed for iodine quantification. For the medium phantom configuration (15 cm diameter), measurement errors in iodine density, effective atomic number, and electron density (ED) were below 0.3 mg/mL, 0.2 and 1.8 %EDwater, respectively. The average accuracy was slightly different from scans at 120 kVp; however, not statistically significant for all configurations. Collimation width had no substantial impact. Spectral results were accurate and reliable for radiation exposures down to 0.9 mGy CTDIvol. Detector-based DECT at 100 kVp can provide on-demand or retrospective spectral information with high accuracy even at extremely low doses, thereby making it an attractive solution for pediatric imaging.