PDF(Pubmed)
Abstract：
OBJECTIVE: This study aimed to elucidate whether gadolinium contrast in clinically relevant doses can be used with photon-counting computed tomography (PCCT) as an alternative contrast agent in clinical applications.
METHODS: A CTDI phantom with 3D printed rods filled with different concentrations of gadolinium and iodine contrast was scanned in a PCCT and an energy-integrated computed tomography (EICT). Attenuation values at different monoenergetic steps were extracted for each contrast concentration.
RESULTS: For PCCT, gadolinium reached an attenuation >100 HU (103 HU) at 40 keV with a concentration 5 mmol/L whereas the same level was reached at 50 keV (118 HU) for 10 mmol/L and 90 keV (114 HU) for 25 mmol/L. For iodine, the same level of attenuation was reached at 100 keV (106 HU) with a concentration 8.75 mg I/mL. For EICT the lowest gadolinium contrast concentration needed to reach >100 HU (108 HU) was 10 mmol/L at 50 keV. For 25 mmol/L 100 HU was reached at 100 keV. For iodine contrast 108 HU was reached at 110 keV for 8.75 mg I/mL.
CONCLUSIONS: No K-edge potential or difference in attenuation curves between iodine and gadolinium contrast is detected on the first clinical available PCCT. Clinically relevant attenuation levels were barely achieved in this setting with gadolinium concentrations approved for human use. The results of this study suggest that, given current scanning technology, gadolinium is not a clinically useful contrast agent for computed tomography because no K-edge was detected.
METHODS: A CTDI phantom with 3D printed rods filled with different concentrations of gadolinium and iodine contrast was scanned in a PCCT and an energy-integrated computed tomography (EICT). Attenuation values at different monoenergetic steps were extracted for each contrast concentration.
RESULTS: For PCCT, gadolinium reached an attenuation >100 HU (103 HU) at 40 keV with a concentration 5 mmol/L whereas the same level was reached at 50 keV (118 HU) for 10 mmol/L and 90 keV (114 HU) for 25 mmol/L. For iodine, the same level of attenuation was reached at 100 keV (106 HU) with a concentration 8.75 mg I/mL. For EICT the lowest gadolinium contrast concentration needed to reach >100 HU (108 HU) was 10 mmol/L at 50 keV. For 25 mmol/L 100 HU was reached at 100 keV. For iodine contrast 108 HU was reached at 110 keV for 8.75 mg I/mL.
CONCLUSIONS: No K-edge potential or difference in attenuation curves between iodine and gadolinium contrast is detected on the first clinical available PCCT. Clinically relevant attenuation levels were barely achieved in this setting with gadolinium concentrations approved for human use. The results of this study suggest that, given current scanning technology, gadolinium is not a clinically useful contrast agent for computed tomography because no K-edge was detected.
摘要：
目的：本研究旨在阐明临床相关剂量的钆造影剂是否可以与光子计数计算机断层扫描（PCCT）一起用作临床应用中的替代造影剂。
方法：在PCCT和能量集成计算机断层扫描（EICT）中扫描了带有3D打印棒的CTDI体模，其中填充了不同浓度的钆和碘造影剂。对于每个造影剂浓度，提取了不同单能步骤的衰减值。
结果：对于PCCT，钆在40keV浓度为5mmol/L时达到>100HU(103HU)的衰减,而在50keV(118HU)浓度为10mmol/L时达到相同水平,在90keV(114HU)浓度为25mmol/L时达到相同水平。对于碘，在100keV(106HU)下达到相同的衰减水平,浓度为8.75mgI/mL。对于EICT，达到>100HU（108HU）所需的最低钆造影剂浓度在50keV时为10mmol/L。对于25mmol/L,在100keV下达到100HU。对于碘对比剂,对于8.75mgI/mL,在110keV下达到108HU。
结论：在第一个临床可用的PCCT上没有检测到碘和钆对比剂之间的K边缘电位或衰减曲线差异。在这种情况下，批准用于人类的钆浓度几乎没有达到临床相关的衰减水平。这项研究的结果表明,给定当前的扫描技术，钆不是用于计算机断层扫描的临床有用的造影剂，因为没有检测到K边缘。
方法：在PCCT和能量集成计算机断层扫描（EICT）中扫描了带有3D打印棒的CTDI体模，其中填充了不同浓度的钆和碘造影剂。对于每个造影剂浓度，提取了不同单能步骤的衰减值。
结果：对于PCCT，钆在40keV浓度为5mmol/L时达到>100HU(103HU)的衰减,而在50keV(118HU)浓度为10mmol/L时达到相同水平,在90keV(114HU)浓度为25mmol/L时达到相同水平。对于碘，在100keV(106HU)下达到相同的衰减水平,浓度为8.75mgI/mL。对于EICT，达到>100HU（108HU）所需的最低钆造影剂浓度在50keV时为10mmol/L。对于25mmol/L,在100keV下达到100HU。对于碘对比剂,对于8.75mgI/mL,在110keV下达到108HU。
结论：在第一个临床可用的PCCT上没有检测到碘和钆对比剂之间的K边缘电位或衰减曲线差异。在这种情况下，批准用于人类的钆浓度几乎没有达到临床相关的衰减水平。这项研究的结果表明,给定当前的扫描技术，钆不是用于计算机断层扫描的临床有用的造影剂，因为没有检测到K边缘。
