Inter-scan and inter-scanner variation of quantitative dual-energy CT: evaluation with three different scanner types
Inter-scan and inter-scanner variation of quantitative dual-energy CT: evaluation with three different scanner types
复制标题
DOI：
10.1007/s00330-020-07611-0
复制
发表时间：
2021-01
影响因子：
5.9
通讯作者：
S. Lennartz;A. Parakh;Jinjin Cao;D. Zopfs;N. Grosse Hokamp;A. Kambadakone
中科院分区：
文献类型：
--
作者：
S. Lennartz;A. Parakh;Jinjin Cao;D. Zopfs;N. Grosse Hokamp;A. Kambadakone
目的探讨双源(DsDECT)、快速千伏切换(RsDECT)和双层探测器(DlDECT)重复腹部检查患者在65keV(HU65keV)虚拟单能图像中碘浓度(IC)和衰减的扫描间和扫描间变化。通过在肝、脾、肾、主动脉、门静脉和下腔静脉放置感兴趣区来测量IC和HU65keV。结果三种不同类型的扫描仪显示出相似的体重、体径、年龄、性别、对比剂注射参数以及扫描间差异(Prange：0.23~0.99)。HU65keV和IC的绝对扫描间差异在不同扫描仪之间具有可比性(Prange：0.08-1.0)。IC的总体扫描间变异显著高于HU65keV(p<；0.05)。对于肝脏，rsDECT显示的IC的扫描间变异显著低于dsDECT/dlDECT(p=0.005/0.01)，而对于脾，这种差异仅与dsDECT相比显著(p=0.015)。肝脏对门静脉的IC正常化和脾对主动脉的IC正常化不能显著降低扫描间变异(p=0.97和0.50)。结论不同DECT扫描仪测量的碘含量存在扫描间变异，且大于衰减值的变异。不同扫描仪在纵向变化和整体碘浓度方面的差异取决于所评估的扫描仪对和器官，在临床和科学DECT应用中应予以承认。关键点·所有类型的扫描仪都显示出类似的扫描间衰减变化，而对于碘，快速千伏切换DECT显示肝脏和脾的变异性较小。·碘浓度显示出比衰减测量更高的扫描间变化；血管归一化不能显著改善实质器官碘浓度的扫描间重复性。·三种扫描仪类型之间的总体碘浓度和从两个时间点获得的衰减的差异在大多数被评估的器官和血管的平均患者内和扫描间差异范围内。
ObjectivesTo investigate inter-scan and inter-scanner variation of iodine concentration (IC) and attenuation in virtual monoenergetic images at 65 keV (HU65keV) in patients with repeated abdominal examinations on dual-source (dsDECT), rapid kV switching (rsDECT), and dual-layer detector DECT (dlDECT).MethodsWe retrospectively included 131 patients who underwent two abdominal DECT examinations on the same scanner (dsDECT:n= 46, rsDECT:n= 45, dlDECT:n =40). IC and HU65keVwere measured by placing regions of interest in the liver, spleen, kidneys, aorta, portal vein, and inferior vena cava. Overall IC and HU65keVfor each scanner, their inter-scan differences and proportional variation were calculated and compared between scanner types.ResultsThe three scanner-specific cohorts showed similar weight, body diameter, age, sex, and contrast media injection parameters as well as inter-scan differences hereof (prange: 0.23–0.99). Absolute inter-scan differences of HU65keVand IC were comparable between scanners (prange: 0.08–1.0). Overall inter-scan variation was significantly higher in IC than HU65keV(p< 0.05). For the liver, rsDECT showed significantly lower inter-scan variation of IC compared to dsDECT/dlDECT (p= 0.005/0.01), while for the spleen, this difference was only significant compared to dsDECT (p= 0.015). Normalizing IC of the liver to the portal vein and of the spleen to the aorta did not significantly reduce inter-scan variation (p= 0.97 and 0.50).ConclusionsIodine measurements across different DECT scanners show inter-scan variation which is higher compared to variation of attenuation values. Inter-scanner differences in longitudinal variation and overall iodine concentration depend on the scanner pairs and organs assessed and should be acknowledged in clinical and scientific DECT applications.Key Points• All scanner types showed comparable inter-scan variation of attenuation, while for iodine, the rapid kV switching DECT showed lower variability in the liver and spleen.• Iodine concentration showed higher inter-scan variation than attenuation measurements; normalization to vessels did not significantly improve inter-scan reproducibility of iodine concentration in parenchymal organs.• Differences between the three scanner types regarding overall iodine concentration and attenuation obtained from both timepoints were within the range of average intra-patient, inter-scan differences for most assessed organs and vessels.