Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45147 Essen, Germany.
Siemens Healthcare GmbH, Forchheim, Germany.
Acad Radiol. 2018 Feb;25(2):153-158. doi: 10.1016/j.acra.2017.08.011. Epub 2017 Oct 18.
This study aimed to determine the optimal tube potential for unenhanced chest computed tomographies (CTs) with age-related phantoms.
Three physical anthropomorphic phantoms (newborn, 5-year-old child, and adult) were scanned on a third-generation dual-source CT using CAREkV in semi-mode and CAREDose4D (ref. KV: 120; ref. mAs 50). Scans were performed with all available tube potentials (70-150 kV and Sn150 kV). The lowest volume computed tomography dose index (CTDI) was selected to perform additional Sn100-kV scans with matched and half (Sn100-half) CTDI value. Image quality was evaluated on the basis of contrast-to-noise ratio (CNR).
For the newborn phantom, 70-110 kV was selected as the optimal range (0.36-0.37 mGy). Using Sn150 kV led to an increase in radiation dose (0.75 mGy) without improving CNR (96.9 vs 101.5). Sn100-half showed a decrease in CNR (73.1 vs 101.5). The lowest CTDI for the child phantom was achieved between 100 and 120 kV (0.78-0.80 mGy). Using Sn150 kV increased radiation dose (1.02 mGy) without improvement of CNR (92.4 vs 95.8). At Sn100-half CNR was decreased (61.4 vs 95.8). For adults, 140 and 150 kV revealed the lowest CTDI (2.68 and 2.67 mGy). The Sn150 kV scan delivered comparable CNR (54.4 vs 56.6), but a lower CTDI (2.08 mGy). At Sn100-half CNR was comparable to the 150 kV scan (58.1 vs 56.6).
Unenhanced chest CT performed at 100 kV or 150 kV with tin filtration enables radiation dose reduction for the adult phantom, but not for the pediatric phantoms.
本研究旨在利用与年龄相关的体模确定非增强胸部 CT 的最佳管电压。
使用第三代双源 CT 上的半模式 CAREkV 和 CAREDose4D（参考 kV：120；参考 mAs：50）对三个物理人体模型体模（新生儿、5 岁儿童和成人）进行扫描。使用所有可用的管电压（70-150kV 和 Sn150kV）进行扫描。选择最低的容积 CT 剂量指数（CTDI）进行 Sn100-kV 扫描，以获得匹配和减半（Sn100-half）CTDI 值。根据对比噪声比（CNR）评估图像质量。
对于新生儿体模，选择 70-110kV 作为最佳范围（0.36-0.37mGy）。使用 Sn150kV 会导致辐射剂量增加（0.75mGy），而 CNR 无改善（96.9 对 101.5）。Sn100-half 显示 CNR 降低（73.1 对 101.5）。儿童体模的最低 CTDI 是在 100-120kV 之间获得的（0.78-0.80mGy）。使用 Sn150kV 会增加辐射剂量（1.02mGy），但 CNR 没有改善（92.4 对 95.8）。在 Sn100-half 时，CNR 降低（61.4 对 95.8）。对于成年人，140kV 和 150kV 显示出最低的 CTDI（2.68 和 2.67mGy）。Sn150kV 扫描的 CNR 相当（54.4 对 56.6），但 CTDI 较低（2.08mGy）。在 Sn100-half 时，CNR 与 150kV 扫描相当（58.1 对 56.6）。
对于成人体模，用锡滤过的 100kV 或 150kV 进行非增强胸部 CT 可以降低辐射剂量，但对于儿科体模则不然。
