双能量CT非线性融合优化对比技术对甲状腺结节图像质量的影响

Effect of non-linear image blending optimal contrast technique using dual-energy CT on thyroid nodules

目的定量评价双能量CT非线性融合优化对比对甲状腺结节图像质量的影响。方法回顾性分析94例接受双源CT双能量增强扫描的甲状腺病变患者,分别比较80kV(A组)、140kV(B组)、线性融合0.3LB(C组)及非线性融合NLB(D组)4组图像中颈动脉、正常甲状腺组织及甲状腺病灶3个部位的CT值、SNR、CNR,比较4组图像的背景噪声。主观评分比较C、D两组对甲状腺病灶的包膜及内部结构的显示情况。结果 C组与D组背景噪声差异无统计学意义(P=0.59),小于A、B两组;A组与D组颈动脉、正常甲状腺组织及甲状腺病灶的CT值差异无统计学意义(P=0.49、0.08、0.08),大于其他两组。C、D两组正常甲状腺SNR差异无统计学意义(P=0.19),均大于A、B组(P均<0.05);D组颈动脉SNR及CNR、甲状腺病灶SNR及CNR、正常甲状腺CNR均大于其他3组(P均<0.05)。C、D两组图像的主观评分分别为3.36±0.51、4.01±0.56,D组优于C组(P=0.02)。结论非线性融合可提高颈部图像质量,更清晰地显示甲状腺结节的包膜及乳头结构,对结节的CT定性诊断有一定的临床价值。

Objective To evaluate effect of non-linear image blending optimal contrast technique with dual-energy CT in thyroid nodules. Methods Totally 94 patients with thyroid nodules underwent contrast-enhanced dual-energy CT neck scan. Images were divided into 4 groups, including 80 kV （group A）, 140 kV （group B）, linear blending 0.3LB （group C） and non-linear blending NLB （group D）. CT value, SNR, CNR of arteria carotis, normal thyroid, thyroid nodules and the background noise of images were compared respectively among 4 groups. The subjective image quality score were compared between group C and group D. Results The background noise of images in group C and D had no statistical differences （P=0.59）, while the data all less than those of group A and group B. CT value of arteria carotis, normal thyroid, thyroid nodules between group A and D had no statistical differences （P= 0, 49, 0.08, 0.08）, which were higher than those of group B and C. SNR and CNR of arteria carotis, thyroid nodules in group D, CNR of normal thyroid were higher than those in other groups, which had statistical differences （all P〈0.05）. The subjective image quality score in group C and group D were 3.36±0.51, 4.01±0.56, image quality in group D was better than group C （P=0.02）. Conclusion NLB image could improve the image quality of neck, and clearly display capsule and internal structure of thyroid nodules, which have value in differentiating malignant from benign thyroid nodules.