原始数据迭代重建和智能最佳管电压技术对降低颞骨扫描辐射剂量的比较

摘要

目的：探讨低管电压、原始数据迭代重建（SAFIRE）和智能最佳管电压扫描（CARE kV）技术对降低颞骨高分辨率CT（HRCT）辐射剂量的价值及其对图像质量的影响。资料与方法因耳部疾病行HRCT扫描的90例患者按就诊时间随机分为常规扫描组（A组）CARE kV组、（B组）、低管电压组（C组），每组各30例。由2名主治医师采用双盲法对3组图像质量评分进行评价，并比较3组平均CT值、噪声、对比噪声比（CNR）、信噪比（SNR）、容积CT剂量指数（CTDIvol）、剂量长度乘积（DLP）、有效剂量（ED）。结果3组图像质量评分及平均CT值差异无统计学意义（F=3.70、3.61, P>0.05）；噪声、CNR、SNR、CTDIvol、DLP及ED差异有统计学意义（F=1.23、1.42、2.05、2.13、1.79、1.32, P<0.05），与B组相比，C组噪声降低约14.1%，CNR、SNR提高约32.1%、26.3%（q=3.64、3.45、4.36, P<0.05）。B、C组CTDIvol、DLP、ED差异有统计意义（q=3.13、4.24、4.24, P<0.05）。结论应用低管电压、SAFIRE和CARE kV技术进行颞骨HRCT扫描时，不仅可以有效地降低辐射剂量，还能获得满意的图像质量，值得推广应用。%Purpose To explore the value of low tube voltage, original data iterative reconstruction (SAFIRE) and intelligent optimum tube voltage scanning (CARE kV) technology in reducing radiation dose of high resolution CT (HRCT) temporal bone scanning and its impact on image quality. Materials and Methods Ninety patients with ear problem underwent clinical HRCT scan. All the patients were randomly divided into group A (conventional scanning), group B (CARE kV) and group C (low tube voltage) according to chronological order, with 30 cases in each group. Image quality was double-blind scored by two qualified radiologists. CT value, noise, contrast to noise ratio (CNR), signal to noise ratio (SNR), CT dose index volume (CTDIvol), dose-length product (DLP) and effective dose (ED) were compared among three groups. Results Image quality and the average CT value had no statistical difference among three groups (F=3.70, 3.61;P>0.05);noise, CNR, SNR, CTDIvol, DLP and ED had statistical difference among three groups (F=1.23, 1.42, 2.05, 2.13, 1.79, 1.32; P<0.05). Compared with group B, noise reduced about 14.1%in group C, while CNR and SNR increased about 32.1%and 26.3%, respectively (q=3.64, 3.45, 4.36; P<0.05). CTDIvol, DLP and ED were significantly different between group B and group C (q=3.13, 4.24, 4.24; P<0.05). Conclusion Scanning with low tube voltage, SAFIRE and CARE kV technology not only effectively reduce radiation dose, but also obtain satisfactory image quality. It should be widely utilized.