From the Department of Radiology (Z.T., L.Z., X.S., M.Y., J.M., H.W., J.W.), Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Hubei Province Key Laboratory of Molecular Imaging (Z.T., L.Z., X.S., M.Y., J.M., H.W., J.W.), Wuhan, Hubei, China.
AJNR Am J Neuroradiol. 2023 Oct;44(10):1212-1218. doi: 10.3174/ajnr.A7999. Epub 2023 Sep 21.
Radiation exposure in the CT diagnostic imaging process is a conspicuous concern in pediatric patients. This study aimed to evaluate whether 60-keV virtual monoenergetic images of the pediatric cranium in dual-layer CT can reduce the radiation dose while maintaining image quality compared with conventional images.
One hundred six unenhanced pediatric head scans acquired by dual-layer CT were retrospectively assessed. The patients were assigned to 2 groups of 53 and scanned with 250 and 180 mAs, respectively. Dose-length product values were retrieved, and noise, SNR, and contrast-to-noise ratio were calculated for each case. Two radiologists blinded to the reconstruction technique used evaluated image quality on a 5-point Likert scale. Statistical assessment was performed with ANOVA and the Wilcoxon test, adjusted for multiple comparisons.
Mean dose-length product values were 717.47 (SD, 41.52) mGy×cm and 520.74 (SD, 42) mGy×cm for the 250- and 180-mAs groups, respectively. Irrespective of the radiation dose, noise was significantly lower, SNR and contrast-to-noise ratio were significantly higher, and subjective analysis revealed significant superiority of 60-keV virtual monoenergetic images compared with conventional images (all < .001). SNR, contrast-to-noise ratio, and subjective evaluation in 60-keV virtual monoenergetic images were not significantly different between the 2 scan groups ( > .05). Radiation dose parameters were significantly lower in the 180-mAs group compared with the 250-mAs group ( < .001).
Dual-layer CT 60-keV virtual monoenergetic images allowed a radiation dose reduction of 28% without image-quality loss in pediatric cranial CT.
在 CT 诊断成像过程中，辐射暴露是儿科患者的一个显著关注点。本研究旨在评估在双层 CT 中，60keV 的虚拟单能量颅骨图像是否可以在保持图像质量的同时，与常规图像相比降低辐射剂量。
回顾性评估了 106 例经双层 CT 增强的儿科头颅扫描。患者被分为两组，每组 53 例，分别以 250 和 180mAs 进行扫描。获取每个病例的剂量长度乘积值，并计算噪声、信噪比和对比噪声比。两名对重建技术不知情的放射科医生使用 5 分李克特量表对图像质量进行评估。使用方差分析和 Wilcoxon 检验进行统计评估，并进行了多次比较调整。
250mAs 组和 180mAs 组的平均剂量长度乘积值分别为 717.47（标准差 41.52）mGy×cm 和 520.74（标准差 42）mGy×cm。无论辐射剂量如何，噪声均显著降低，信噪比和对比噪声比均显著提高，主观分析显示 60keV 虚拟单能量图像明显优于常规图像（均<.001）。在 2 个扫描组之间，60keV 虚拟单能量图像的 SNR、对比噪声比和主观评价没有显著差异（>.05）。180mAs 组的辐射剂量参数显著低于 250mAs 组（<.001）。
在儿科头颅 CT 中，双层 CT 的 60keV 虚拟单能量图像可在不降低图像质量的情况下降低 28%的辐射剂量。
