3.0 T MR动脉自旋标记灌注技术评价正常成年人甲状腺血流灌注的价值

Value of arterial spin label technique in 3.0 T MR scanner on evaluating blood flow of thyroid glands in healthy adults

目的探讨三维动脉自旋标记(3D-ASL)技术评估正常成年人甲状腺血流量(TBF)的可行性和稳定性,并比较不同性别、年龄受试者TBF的差异。方法前瞻性收集2018年9月至2019年6月在中国医学科学院肿瘤医院深圳医院进行甲状腺MR检查的100名健康成年受试者,均接受3.0 T MR甲状腺3D-ASL扫描,1名受试者因不能耐受检查、11名因图像伪影明显、15名因常规MRI发现甲状腺异常而排除,最终入组73名受试者。由2名放射科主治医师对ASL图像质量进行独立评分,并分别测量甲状腺双侧叶上、中、下极的TBF。2名医师图像质量评分的一致性采用Kappa分析,测量TBF的一致性采用组内相关系数(ICC)进行评价。同侧甲状腺上、中、下极的TBF比较采用单因素方差分析。双侧甲状腺之间,不同性别、年龄组间同侧甲状腺TBF比较采用配对或独立样本t检验。结果2名医师图像质量评分的一致性良好(Kappa=0.753,P<0.001)。2名医师测量TBF的一致性甲状腺左侧叶下极ICC=0.648(P<0.001),其他部位一致性良好(ICC均>0.75,P<0.001)。同侧中极TBF明显高于上、下极(P<0.001),而同侧上、下极差异无统计学意义(P>0.05)。右侧上、中、下极的TBF均大于左侧(t=6.182、6.294、4.896,P<0.001)。男性(31名)与女性(42名)受试者间同侧甲状腺上、中、下极TBF差异无统计学意义(P>0.05)。中年组(45~59岁,12名)甲状腺中极TBF高于青年组(18~44岁,61名)(左侧叶t=3.868,P=0.003;右侧叶t=2.647,P=0.022),而两组同侧上、下极TBF差异无统计学意义(P>0.05)。结论ASL能精准定量甲状腺血流灌注情况,并具有良好的可重复性。

Objective To investigate the feasibility and reproducibility of using three-dimensional arterial spin labeling(3D-ASL)technique to evaluate the thyroid blood flow(TBF)in healthy adults and compare the difference in TBF between subjects with different gender and age.Methods In this prospective study,100 healthy adult subjects were enrolled from November 2018 to June 2019 in Chinese Academy of Medical Sciences Cancer Hospital,Shenzhen Hospital.All subjects received thyroid 3D-ASL MRI scanning,but several subjects were excluded from analysis for reasons including intolerance to examination(n=1),overt artifacts(n=11),abnormality detected in thyroid gland during conventional MRI(n=15),resulting in 73 subjects included.Two attending radiologists independently evaluated the quality of ASL images and measured the TBF in upper,middle and lower poles of each lobe in thyroid gland bilaterally.Cohen’s Kappa was used to test the agreement in image quality between 2 radiologists,while intraclass correlation(ICC)analysis was implemented to evaluate the consistency in TBF measurements.Univariate variance analysis was used to compare the TBF in upper,middle and lower pole of thyroid gland unilaterally,and student t-test was performed to test the difference in TBF between two lobes,or in the same lobe but between different gender or age groups.Results For image quality,2 radiologists have good agreement(Kappa=0.753,P<0.001).In terms of TBF,consistency was moderate in the lower pole of left lobe between 2 radiologists(ICC=0.648,P<0.001),but good in the remaining parts of thyroid gland(all ICC>0.75,P<0.001).Unilaterally,TBF in the middle pole was significantly higher than those in the upper or lower pole(P<0.001),but no significant difference was found between the upper and lower pole(P>0.05).Regardless of upper,middle or lower pole,TBF in the right lobe was higher than the counterpart in the left lobe(t=6.182,6.294,4.896,P<0.001).Between male subjects(n=31)and female subjects(n=42),no significant difference was found in the corresponding upper,middle or lower pole of thyroid lobe unilaterally(P>0.05).As for age group,TBF in the middle pole of thyroid gland was higher in the middle age group(45-59 years old,n=12)than that in the young adult group(18-44 years old,n=61)(t=3.868,P=0.003 for the left lobe,and t=2.647,P=0.022 for the right lobe),but no significant difference was found in the upper or lower pole of the unilateral thyroid lobe(P>0.05).Conclusion ASL can accurately measure blood flow perfusion in the thyroid gland with good reproducibility.