甲状腺良恶性结节的超声特征及血流情况分析

Ultrasonic characteristics and blood flow analysis of benign and malignant thyroid nodules

目的观察甲状腺良恶性结节的超声特征、血流情况及微血管密度(MVD)值,探讨超声鉴别诊断结节良恶性的可行性。方法选取经手术病理证实的112例甲状腺结节患者(共128个结节),二维超声观察其大小、纵横比、形态、边界、内部回声及有无钙化;应用半定量方法对结节内彩色血流信号进行分级,并对其内部血流分布进行分型。采用免疫细胞化学方法以CD34 标记结节内部的微血管内皮细胞,半定量计算MVD 值。结果128 个结节中,恶性结节81个,良性结节47个。良恶性结节在低回声、形态不规则、边界不清晰、纵横比≥1及是否有微小钙化等方面比较差异均有统计学意义(均P<0.05)。100个结节为多血供,28个为少血供。67个恶性结节呈病灶中心型或周边环绕的血管分布,14个恶性结节病灶内无血管;38个良性结节呈病灶中心型或周边环绕的血管分布,9个良性结节病灶内无血管。恶性结节MVD值为39.6±5.7,显著低于良性结节MVD值72.1±6.2,差异有统计学意义(P<0.05)。结论甲状腺结节的二维超声特征如低回声、形态不规则、边界不清晰、纵横比≥1及是否有微小钙化具有较高的鉴别诊断价值,结节中心部位的血流增多不能作为鉴别诊断的关键依据,恶性结节内部MVD值低于良性结节,其机理尚待进一步研究。

Objective To observe the ultrasonic characteristics,blood flow and microvessel density(MVD)of benign and malignant thyroid nodules,and to explore the feasibility of differential diagnosis of benign and malignant thyroid nodules by ultrasonography. Methods A total of 112 patients with 128 thyroid nodules confirmed by operation and pathology were retrospectively analyzed. Two-dimentional features about the nodular size,aspect ratio,shape,boundary,inner echogenicity and microcalcifications were carefully observed and measured,blood flow signals inside the nodular lesions were graded semi-quantitatively,and the distribution of blood flow signals were classified as graded types. Moreover,the value of microvessel density(MVD) was semi-quantitatively measured and calculated through microvessel endothelium labelled by immunocytochemical method with CD34.Results Of all these 128 nodules,81 nodules were malignant and 47 were benign. There were significant differences between malignant and benign nodules in low inner echogenicity,irregular shape,indistinct boundary,aspect ratio ≥1 and inner microcalcification(all P < 0.05). 100 nodules were hypervascularity,the other 28 were hypovascular. Among those malignant nodules,67 nodules showed polycentric or surrounding flow signals,while 14 of them showed hypovascular inside the nodules. And of those benign nodules,38 nodules manifested as polycentric or surrounding flow signals,and 9 as hypovascular inside the nodules. The values of MVD of malignant nodules(39.6±5.7)were significantly higher than that of begine nodules(72.1±6.2),there was significant difference(P < 0.05).Conclusion Two-dimentional ultrasound features such as low echogenicity,irregular shape,indistinct boundary,aspect ratio ≥1 and intranodular microcalcifications may have much higher differential diagnostic value. Increased polycentric or surrounding blood flow signals are important sonographic features,but should not be considered as key point for differential diagnosis. The value of MVD in the malignant nodules is obviously lower than that of the benign nodules,which should be futher investigated.