The value of contrast-enhanced ultrasonography in differential diagnosis of thyroid microcarcinoma of TI-RADS grade 3-4

Abstract

Objective To provide a reference for differential diagnosis of thyroid microcarcinoma classified as TI-RADS 3-4 grade using contrast-enhanced ultrasound. Methods SonoLiver software was used to analyze the process of contrast-enhanced ultrasound of 112 thyroid small nodules classified as TI-RADS 3-4 grade. The dynamic vascular pattern curve (DVPC) and the time-intensity curve (TIC) were automatically acquired for summarization of the types and characteristics of the two curves. The relevant parameters such as the rise time (RT), time to peak (TTP), maximum intensity (IMAX%), mean transit time (mTT), area under curve (AUC) and perfusion index (PI) were acquired and calculated using the software. Receiver operating curve (ROC) analysis was used to achieve the cut-off value of these parameters for differential diagnosis. Results For thyroid microcarcinoma which TI-RADS assessment of grade 3-4, TIC showed as slow rise and slow drop wave or slow rise and fast drop wave, DVPC showed negative waveform or negative-positive bi-directional waveform. ROC analysis demonstrated that IMAX of 96.5%, AUC of 443.08 and PI of 47.64 were the best cut-off values for the differential diagnosis of benign and malignant nodules. When IMAX<96.5%, AUC<443.08, PI<47.64, the nodules were highly likely to be thyroid microcarcinoma. Conclusions The contrast-enhanced ultrasound parameters can provide effective reference for the differential diagnosis of thyroid carcinoma with grade 3-4 in TI-RADS classification. Key words: Contrast-enhanced ultrasonography; Thyroid microcarcinoma; TI-RADS; Time-intensity curve; Dynamic vascular pattern