能谱CT基物质成像技术定量测量活体甲状腺碘含量

摘要

目的 分析能谱CT基物质成像技术用于定量测定活体甲状腺正常组织碘含量的价值,并与混合能量CT值进行对比.方法 对48例结节性甲状腺肿患者行能谱CT成像,重建140 kVp混合能量图像、碘基密度图和水基密度图,测量ROI的140 kVp混合能量CT值、碘密度值、水密度值,分别比较三者的相关性,以及不同年龄(＞60岁、40～60岁、＜40岁)患者的混合能量CT值与碘密度值、水密度值的差异性,并比较不同CT值＜100 HU、≥100 HU)的水密度值的差异.结果 140 kVp混合能量CT值[69.79～151.31 HU,平均(103.12±16.36)HU],与碘密度值[0.05～2.46 mg/ml,(1.01±0.58) mg/ml]有相关性(r=0.687,P＜0.01),与水密度值[1039.8～1090.81 mg/ml,平均(1064.95±11.58)mg/ml]未见相关(r=0.037,P＞0.05).年龄＞60岁及40～60岁者的混合能量CT值分别与年龄＜40岁者比较,差异均有统计学意义(P＜0.05),其余各年龄段的碘密度值、水密度值差异均无统计学意义.140 kVp混合能量CT值＜100 HU与≥100 HU患者的水密度值差异无统计学意义(P＞0.05).结论 相比混合能量CT值,能谱CT基物质成像能更直接地定量测量活体甲状腺碘含量.%Objective To analyze the value of material decomposition images in quantitative in vivo measurement of iodine concentration in normal thyroid compared with CT values in 140 kVp polychromatic CT mapping. Methods Totally 48 patients (16 males and 32 females) underwent gemstone spectral imaging. Monochromatic images and iodine and water-based material decomposition images were reconstructed. Iodine, water concentration and 140 kVp polychromatic CT values of ROI in thyroid tissue were measured. Relationship between iodine and water concentration with 140 kVp polychromatic CT values were analyzed. Differences of iodine, water concentration and 140 kVp polychromatic CT values were compared a-mong patients with different ages (>60 years old, 40-60 years old, <40 years old), as well as 140 kVp polychromatic CT values(<100 HU, ≥100 HU). Results Statistical analysis showed correlation (r=0. 687, P<0. 01) between iodine concentration (0. 05-2. 46 mg/ml, mean [ 1. 01 ± 0. 58] mg/ml) and 140 kVp polychromatic CT values ( 69. 79- 151. 31 HU, mean [103. 12 ±16. 36]HU). There was no correlation (r=0. 037,P>0. 05) between water concentration (1039. 8-1090. 81 mg/ml, mean [1064. 95±11. 58] mg/ml) and 140 kVp polychromatic CT values. Compared to patients <40 years old, 140 kVp polychromatic CT values of patients >60 years old and 40-60 years old had statistical significance (both P<0. 05). Water concentration of thyroid tissue with different 140 kVp polychromatic CT values had no statistical difference (P>0. 05). Conclusion Quantifying iodine concentration of normal thyroid using gemstone spectral imaging is better than 140 kVp polychromatic CT values.