甲状腺CT增强扫描中常规模式扫描和双能量扫描的图像质量与辐射剂量的比较

Comparison of Image Quality and Radiation Dose between Conventional Scanning and Dual-energy Scanning in Enhanced Thyroid CT Scanning

目的本研究旨在比较甲状腺CT增强扫描中采用常规扫描方案与双能量扫描方案对图像质量与辐射剂量的差异。方法回顾性收集行甲状腺CT增强检查且身体质量指数为18.5-23.9kg/㎡的患者87例。根据扫描方式的不同分为A、B两组,A组用常规模式扫描方案,采用50%ASIR-Ⅴ重组算法进行重组图像;B组用双能量模式扫描方案,采用50%ASIR-Ⅴ重组算法并以60Kev单能量重建。分别比较两组图像的甲状腺CT值、噪声、信噪比、对比噪声比及图像质量主观评分。并记录两组图像的容积CT剂量指数、剂量-长度乘积与有效剂量。采用Mann-Whitney两独立样本U检验和Wilcoxon符号秩和检验比较两组图像质量及辐射剂量的差异。结果A组和B组在甲状腺动脉期和静脉期的图像CT值差异均有显著统计学意义(P<0.05),两组图像的噪声在平扫期和动脉期之间差异有统计学意义,而动脉期和静脉期的图像信噪比差异无统计学意义(P>0.05),两组图像的对比噪声比在动脉期和静脉期的差异存在统计学意义(P<0.05),两组在剂量-长度乘积与有效剂量方面各期的差异均有统计学意义(P<0.05)。结论在甲状腺CT增强扫描中,采用双能量扫描方案能够在不降低图像质量的同时显著降低患者的辐射剂量。

ObjectiveThis study aims to compare the differences in image quality and radiation dose between conventional scanning protocols and dual-energy scanning protocols in contrast-enhanced thyroid CT scans.MethodsA retrospective collection of 87 patients with a body mass index of 18.5-23.9kg/m^(2) undergoing thyroid CT enhancement examination was divided into two groups,a and B,according to different scanning protocols.group a adopted the conventional mode scanning scheme,and uses the 50%aSIR-V recombination algorithm to reorganize the images,group B adopted the spectral imaging protocol,50%aSIR-V recombination algorithm,and 60Kev single energy reconstruction.Thyroid CT value,noise,signal-to-noise ratio,contrast-to-noise ratio,and subjective image quality score were compared between the two groups.The volume CT dose index,dose-length product,and effective dose of the images of the two groups of images were recorded.Mann-Whitney two independent samples u test and Wilcoxon signed-rank test were used to compare the differences in image quality and radiation dose between the two groups.ResultsThe CT values of the thyroid arterial phase and the venous phase of the two groups of images were significantly different(P<0.05),and the image noise of the two groups was significantly different in the plain scan phase and the arterial phase,while the signal-to-noise ratio differences between arterial and venous phases were not statistically significant(P>0.05).The contrast-to-noise ratio showed significant differences between the arterial and venous phases(P<0.05).Both the dose-length product and effective dose showed significant differences between the two groups in all phases(P<0.05).ConclusionIn contrast-enhanced thyroid CT scans,dual-energy scanning protocols can significantly reduce radiation dose without compromising image quality.