Marcus Roy P, Koerner Elise, Aydin Roland C, Zinsser Dominik, Finke Tobias, Cyron Christian J, Bamberg Fabian, Nikolaou Konstantin, Notohamiprodjo Mike
Institute of Diagnostic and Interventional Radiology, Eberhard-Karls-Universität, Tübingen, Germany; Department of Radiology, Mayo Clinic, Rochester, MN, United States.
Institute of Diagnostic and Interventional Radiology, Eberhard-Karls-Universität, Tübingen, Germany.
Eur J Radiol. 2017 Jan;86:63-69. doi: 10.1016/j.ejrad.2016.11.002. Epub 2016 Nov 5.
To evaluate and compare the radiation dose and image quality of whole-body-CT (WBCT) performed on the 3rd-generation dual-source-CT (DSCT) with 2nd-generation DSCT and 64-slices-Single-Source-CT (SSCT) in a large patient cohort.
Using a monitoring and tracking software 1451, 747 and 1861 patients scanned with a one-spiral-thorax-abdomen-pelvis-CT-examination on a 3rd-, 2nd-generation DSCT and SSCT, respectively, were extracted from the PACS server. For the intra-individual analysis, 203 patients on the 3rd-generation DSCT were identified. Out of those 203 patients, 155 had the same examination on the 2nd-generation DSCT, 91 patients had the same examination on the SSCT and 43 patients had an examination on all three CT-generations. Automatic tube current modulation was active on all three CT-generations, whereas automatic tube voltage selection was only available on both DSCT-generations. Dose was recorded by the size-specific-dose-estimate-method (SSDE); signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) were calculated placing a ROI on the ascending aorta/liver and the subcutaneous adipose tissue at comparable level. Image quality of axillary and mediastinal lymph nodes and adrenal glands was assessed by two experienced radiologists.
Subjective image quality was excellent throughout all three CT-generations (p=0.38-0.98). Quantitative image quality in both DSCT generations was superior to SSCT (p<0.001). SNR and CNR in the liver parenchyma were superior in the 3rd-generation DSCT compared to the 2nd generation DSCT (p<0.001), whereas there was no difference in the aorta. In the inter-individual analysis, CTDI was lower by 26.9% and 44.3% in the 3rd-generation DSCT, when compared to the 2nd-generation DSCT and SSCT, respectively; SSDE was lower by 31.5% and 51% in the 3rd-generation DSCT, when compared to the 2nd-generation DSCT and SSCT, respectively. In the intra-individual comparison CTDI in the 3rd-generation DSCT was lower by 33% and 45%, when compared to the 2nd-gneration DSCT and the SSCT, respectively. Consequently, SSDE in the 3rd-generation DSCT was lower by 29% and by 43% when compared to the 2nd-generation DSCT and SSCT, respectively.
State-of-the-art CT-equipment substantially reduce radiation dose without affecting image quality.
在大量患者队列中评估并比较第三代双源CT（DSCT）、第二代DSCT和64层单源CT（SSCT）进行的全身CT（WBCT）的辐射剂量和图像质量。
使用监测和跟踪软件，分别从PACS服务器中提取在第三代、第二代DSCT和SSCT上进行单螺旋胸部-腹部-骨盆CT检查的1451例、747例和1861例患者。对于个体内分析，确定了第三代DSCT上的203例患者。在这203例患者中，155例在第二代DSCT上进行了相同检查，91例在SSCT上进行了相同检查，43例在所有三代CT上均进行了检查。所有三代CT均启用自动管电流调制，而自动管电压选择仅在两代DSCT上可用。剂量通过尺寸特异性剂量估计方法（SSDE）记录；在升主动脉/肝脏和相当水平的皮下脂肪组织上放置感兴趣区（ROI）计算信噪比（SNR）和对比噪声比（CNR）。由两名经验丰富的放射科医生评估腋窝和纵隔淋巴结以及肾上腺的图像质量。
在所有三代CT中主观图像质量均极佳（p = 0.38 - 0.98）。两代DSCT的定量图像质量均优于SSCT（p < 0.001）。与第二代DSCT相比，第三代DSCT肝脏实质的SNR和CNR更高（p < 0.001），而主动脉中无差异。在个体间分析中，与第二代DSCT和SSCT相比，第三代DSCT的CTDI分别降低了26.9%和44.3%；与第二代DSCT和SSCT相比，第三代DSCT的SSDE分别降低了31.5%和51%。在个体内比较中，与第二代DSCT和SSCT相比，第三代DSCT的CTDI分别降低了33%和45%。因此，与第二代DSCT和SSCT相比，第三代DSCT的SSDE分别降低了29%和43%。
最新的CT设备在不影响图像质量的情况下大幅降低了辐射剂量。
