Diagnostic Value of Conventional Ultrasonography Combined with Contrast-Enhanced Ultrasonography in Thyroid Imaging Reporting and Data System (TI-RADS) 3 and 4 Thyroid Micronodules

Abstract

BACKGROUND The present study was conducted to investigate the diagnostic performance of conventional ultrasonography (US) combined with contrast-enhanced ultrasonography (CEUS) in thyroid micronodules with thyroid imaging reporting and data system (TI-RADS) category 3 and 4. MATERIAL AND METHODS The features of conventional US and CEUS ion 102 case of thyroid micronodule samples, which were diagnosed based on pathological and clinical examination, were retrospectively analyzed. Logistic regression analysis was used to analyze the diagnostic accuracy in malignant thyroid micronodules. Receiver operator characteristic (ROC) curve was used to assess the performance of those 2 technologies. RESULTS A significant difference in age was found between the benign and malignant groups. The benign and malignant groups showed significant differences in shape, margin, aspect ratio (A/T) ≥1, microcalcification, suspicious lymph gland, enhancement time, enhancement pattern, enhancement intensity, nodule sizes, enhancement margins, and rim-like enhancement. Logistic regression analysis of conventional US showed that A/T ≥1, irregular shape, microcalcification, and suspicious lymph glands are risk factors for thyroid micronodules, while logistic regression analysis of CEUS showed that slow enhancement time and absence of rim-like enhancement are risk factors for thyroid micronodules. Logistic regression analysis of conventional US combined with CEUS demonstrated that A/T ≥1, microcalcification, suspicious lymph gland, slow enhancement time, and absence with rim-like enhancement are risk factors. The ROC curve for conventional US, CEUS, and conventional US combined with CEUS were 90.0%, 90.7%, 99.0%, respectively. CONCLUSIONS Our results show that conventional US combined with CEUS had superior diagnostic performance for TI-RADS 3 and 4 thyroid micronodules compared with conventional US and CEUS alone.

Figure 1

PTC diagnostic images by conventional US solitary thyroid nodule presented with hypoechogenecityic aspect, unclear margins, aspect ratio ≥1, microcalcification in nodules. PTC, papillary thyroid carcinoma; US, ultrasound.

Figure 2

PTC diagnostic images by color Doppler. No blood flow signals were observed in solitary thyroid nodules. The analysis combined with the results of conventional US indicates the nodules were in TI-RADS 4. PTC, papillary thyroid carcinoma; US, ultrasound.

Figure 3

PTC diagnostic images by CEUS. After 1.0 ml of ultrasound contrast agents was injected for 11 s, the normal thyroid tissue was homogeneously enhanced, while the tissues in solitary thyroid nodules presented with scattered microbubbles, indicating longer enhancement time. PTC, papillary thyroid carcinoma; CEUS, contrast-enhanced ultrasound.

Figure 4

PTC diagnostic images by CEUS. After 1.0 ml of ultrasound contrast agents was injected for 16 s, the normal thyroid tissue was homogeneously enhanced, while the tissues in solitary thyroid nodules was iso-enhanced, with irregular shape and absence of rim-like enhancement. PTC, papillary thyroid carcinoma; CEUS, contrast-enhanced ultrasound.

Figure 5

The ROC curves for conventional US, CEUS, and combined use of conventional US and CEUS. The ROC curve showed that US had an area under the ROC curve (AUC) of 90.0% and CEUS had an AUC of 90.7%, in contrast to the AUC of 99.0% for combined use of conventional US and CEUS. ROC – receiver operator characteristic; US – ultrasound; CEUS – contrast-enhanced ultrasound.