甲状腺微小结节的血管化特征与微血管密度的相关性及其临床意义

目的：观察不同性质的甲状腺结节的血管化特征及其微血管密度变化，进而探讨其鉴别结节良恶性质的可行性。 方法：回顾分析了我院经手术病理证实的112例患者，共计128个结节，其中男性49例共计51个结节，女性63例共计77个结节。观察结节的大小、纵横比值、形态、边界、内部回声、有无钙化等二维形态特征。采用半定量的方法对病灶内部的彩色多普勒血流信号的数量予以分级，对病灶内部血流分布予以分型。采用免疫细胞化学方法以CD34标记病灶内部的微血管内皮细胞，并半定量方法计算微血管的密度。 结果：所有128个结节中病理恶性的结节81例，病理非恶性的结节47例。病理恶性与非恶性结节在低回声、不规则形态、不清晰的边界、纵横比≥1、是否有微小钙化等超声声像图特征方面均有显著差异。甲状腺结节内部血流信号的分级显示，约78.12%是相对多血供的，21.88%的结节为少血供的。多血供的结节中恶性结节占64%,良性结节占36%。病理恶性的病灶中，约52.3%呈现病灶中心型或周边环绕的血管分布，约10.9%呈现为病灶内无血管；在病理非恶性的结节中，29.7%呈现病灶中心型或周边环绕的血管分布，约7.0%呈现为病灶内无血管。病理恶性的病灶内部MVD值显著低于病理非恶性病灶内部的MVD值，差异非常显著。 结论：甲状腺结节的低回声、边界不清晰及微小钙化在鉴别病理恶性结节中拥有较好的敏感性与较高的特异性。结节中心部位的血流增多是值得关注的声像图特征，但不能作为鉴别诊断的关键性依据。结节内部新生微血管的密度与彩色多普勒的血流分级或分型之间存在不一致的现象，其机理尚待进一步研究。

Relationship and its Clinical Significance of Nodular Vascularity

Objective It was designed to investigate the possibility of differentiating thyroid nodular malignacy, through observation on its changes of intra-vascularity and microvessel density. Methods Altogether 112 patients with 128 thyroid nodules, which were confirmed by operation and pathology, were retrospectively analyzed. Among these patients, there were 49 males with 51 nodules and 63 females with 77 nodules. Two dimentional features about the nodular size, aspect ratio, shape, boundary, inner echogenicity and microcalcifications were carefully observed and measured. Color Doppler flow imaging (CDFI) signals inside the nodular lesions were graded semi-quantitatively, and the distribution of CDFI 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, there were 81 nodules proved to be patological malignacy, which the other 47 nodules being pathologically non-malignant. There were significant differences between malignant nodules and non-malignant nodules in low inner echogenicity, irregular shape, indistinct boundary, value of aspect ratio great than or equal to 1 and inner microcalcifications.it was showed by intranodular graded Doppler flow signals that about 78.12% of the nodules were hypervascularity, the other 21.88% were hypovascular. Among thoses thyroid nodules with hypervascularity, 64% were malignant and 36% were benign. Moreover, of those malignant nodules, approximately 52.3% showed polycentric or surrounding flow signals, while about 10.9% of them showed hypovascular inside the nodules. On the contrast, of those nonmalignant nodules, only 29.7% manifested as polycentric or surrounding flow signals, and 7.0% as hypovascular inside the nodules. It was also demonstrated that values of MVD inside the malignant nodules were significantly higher than that of the nonmalignant nodules. Conclusion The above results suggested that low echogenicity, indistinct boundary and intranodular microcalcifications may have better specificity and sensitivity. Increased polycentric or surrounding Doppler flow signals were important sonographic features, but should not be considered as key poit for differential diagnosis. There was obvious inconformity between intranodular MVD and intranodular Doppler flow gradings and types, which mechnisms should also be further investigated.