Objective: To study the ultrasonography characteristics of thyroid microcarcinoma.
Methods: the ultrasonographic characteristics of 74 patients (a total of 85 cancer nodules)with thyroid microcarcinoma which confirmed by surgery and pathology were analyzed ,including the size, shape, margin features,echogenity of the components,attenuation,calcification,vascularity, resistance index of the cancer nodule.
Results: In 85 cancer nodules,48 cases were concurred with nodular goiter, 4 cases were concurred with thyroid adenoma.Hypoechogenity in all 85 cancer nodules, solid components in 83 cases 97.6%, mixed echo in 2 cases,2.4%;margins obscured without capsule in 77 cases,90.6%, margins well-circumscribed( no capsule) in 8 cases 9.4%; All cases were round shape; Internal micro-calcification showed in 56 cases (65.9%), the calcification spots clustered at the nodular central in 47 cases, 9 cases were distributed at around;Posterior acoustic shadowing in 27 cases 31.8%,posterior echo unchanged in 54 cases 63.5%, posterior acoustic enhanceing in 4 cases4.7%; 83 cancer nodules showed blood flow signal, accounting for 97.6%, of which, 37 cases were detected clear blood flow spectrum, accounted for 43.5%,with an average flow velocity 24.1 ± 19.4cm/s, average resistance index 0.69±1.2. Hypoechoic,solid components,A/T>1,micro-calcification, internal hypervascularity, high-resistance index, et al were important sonographic features in diagnosis of thyroid microcarcinoma.
Conclusions: The ultrasound imaging of thyroid microcarcinoma has certain ultrasonographic characteristics. If each nodule is analysed according to eight sonographic features of thyroid microcarcinoma ,the diagnosis accuracy can be greatly improved.
Keywords:thyroid microcarcinoma, ultrasonography.