弹性成像技术鉴别诊断甲状腺实性肿块的价值

Evaluation of the elastography in differentiating thyroid solid nodules

目的 初步总结甲状腺不同病理类型肿块的弹性图像特点,并探讨甲状腺弹性成像在鉴别良恶性肿块中的价值.方法 采集116例甲状腺肿物患者共122枚实性肿物的常规和弹性超声图像,请5位超声医师采用双盲法,根据Fukunari提出的4分评分方法,对肿块进行良恶性鉴别.Kappa方法检验超声医师之间的一致性,采用方差分析法比较不同病理类型肿物的弹性评分,ROC曲线方法评价5位超声医师根据弹性图像诊断甲状腺肿块的效能.结果 5位超声医师的评分具有中度一致性.良性肿块的弹性评分多集中在1～3分,明显低于恶性肿块的弹性评分（P＜0.001）.结节性甲状腺肿的弹性评分分布范围较广,平均为（2.67±0.89）分,甲状腺腺瘤评分多为2分.亚急性甲状腺炎评分较高,与甲状腺癌比较差异无统计学意义.根据4分评分法诊断甲状腺良恶性肿块的ROC曲线下面积分别为0.82,0.81,0.79,0.73和0.83.当选择3.5为截断点时,敏感度为82.4%,特异度为71.6%.结论 甲状腺弹性成像能半定量评价肿块的硬度,为临床提供了一个新的诊断指标,在鉴别甲状腺良恶性肿块方面具有较高的临床价值,但4分评分法有待于进一步细化和完善.

Objective To summarize the characters of the elastograms of different pathological nodules, and to observe the value of elastography in differentiating benign from malignant thyroid solid nodules. Methods One hundred and sixteen patients with thyroid nodules were enrolled in the study and 122 nodules were detected in total. All of them were examined by elastography and conventional ultrasound. Five sonographers were invited to evaluate the nodules double blinded basing on the images and the four-point system proposed by Fukunari. The interobserver agreement was evaluated by Kappa coefficient. Diagnostic performances of the five readers were compared by the ROC curves. Distributions of elastography scores of different pathological nodules were compared by one-way ANOVA. Results Interobserver agreements on scoring the nodules were moderate. Mean value of benign nodules was obvious lower than that of the malignant ones. The mean score of nodular goiters was 2.67 ± 0.89, range from 1 to 3. Most of the adenomas got score of 2, but the score of thyroiditis was quite high. No significant differences were found between the comparison of thyroiditis and thyroid cancers. Areas under the ROC curve （AUC） of the five readers were 0.82,0.81,0.79,0.73 and 0.83 respectively. When 3.5 was choosen as the cut-off point, the sensitivity of elastography was 82.4%, and specificity was 71.6%. Conclusions Elastography was really a useful technique for it can provide a new index for the differential diagnosis of thyroid nodules. However, the 4-point score system is not comprehensive enough.