A Clinical Retrospective Study on the Qualitative Value of Multimodal Ultrasonography for ACR-TIRADS 4 Thyroid Nodules Ranging from 1 cm to 1.5 cm

Abstract

Introduction: This study explored the clinical value and application of ultrasound contrast imaging technology in the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) TR4 benign and malignant thyroid nodules.

Methods: We retrospectively analyzed data from the medical records of 40 patients who met the inclusion criteria between January 2020 and December 2023. Each patient was evaluated using the ACR TI-RADS classification and contrast-enhanced ultrasound (CEUS). The agreement between pathological outcomes and ultrasound indicators and the diagnostic value and significance of each parameter were assessed.

Results: The diameters did not differ between benign and malignant nodules (P = 0.324). Ring enhancement was closely associated with benign thyroid nodules, with a negative predictive value of 100%. Homogeneous enhancement and enhancement intensity showed good diagnostic value for pathological results, with an area under the curve (AUC) > 0.8. This parameter showed a high diagnostic value for serial and parallel combinations of homogeneous enhancement and enhancement intensity, with a sensitivity of 77.8% and specificity of 85.7% for the serial combination and 100% and 71.4%, respectively. for the parallel combination.

Conclusion: Among ACR TI-RADS TR4 nodules, diameter 1.0-1.5 cm was not significantly correlated with a benign or malignant nature. Nodules featuring ring enhancement with ring-enhancing features should be considered benign. Similarly, nodules showing no, homogeneous, or high enhancement with clear borders on CEUS imaging may be benign. However, nodules with uneven low enhancement or unclear borders may be malignant. Therefore, uneven and low enhancement on CEUS imaging may have a high diagnostic value for malignant nodules. Moreover, the combination of these features may have even higher specificity.

Keywords: TI-RADS TR4; contrast-enhanced ultrasound imaging; diagnosis; multimodal ultrasonography; thyroid nodule.

Figure 1.

A 30-year-old woman with multiple thyroid nodules that had persisted for >1 year. (a) and (c): Two nodules in the left lobe and isthmus of the thyroid. (a) Two-dimensional ultrasound showing a solid nodule in the lower pole of the left lobe, measuring approximately 12 × 10 × 7 mm³. It appears hypoechoic with smooth margins, an aspect ratio of <1, no calcification, and punctate blood flow signals. The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) classification is TR4. (c) A cystic-solid mixed nodule measuring approximately 13 × 15 × 9 mm³ in the isthmus. The solid portion appears hypoechoic with smooth margins, an aspect ratio of <1, and incomplete peripheral ring-like calcification. Punctate linear blood flow signals are also observed. The ACR TI-RADS classification is TR4. Ultrasound imaging reveals uniform enhancement in (a), suggesting a benign nodule, while (c) shows uneven low enhancement, suggesting a malignant nodule. Postoperative pathology suggests that (a) is consistent with nodular goiter (b, hematoxylin and eosin ×40), while (c) is papillary thyroid carcinoma (d, hematoxylin and eosin ×100).

Figure 2.

A 47-year-old woman with multiple nodules in the right lobe of the thyroid gland discovered during a physical examination >1 month previously. (a) Two-dimensional ultrasound examination shows two nodules in the right lobe of the thyroid gland located at the middle and lower Poles. The nodule in the middle pole of the right lobe was solid and hypoechoic, measuring approximately 10 × 8 × 6 mm³, with blurred margins, a longitudinal-to-transverse ratio <1, and no calcification or blood flow signal. The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) classification is TR4. The nodule in the lower pole of the right lobe was solid and hypoechoic, measuring approximately 11 × 9 × 8 mm³, with blurred margins, a longitudinal-to-transverse ratio <1, and no calcification or blood flow signal. The ACR TI-RADS classification is also TR4. (b) Ultrasound contrast showing that both nodules exhibit unevenly low enhancement; thus showing potential malignancy. (c, papanicolaou ×100) Fine needle aspiration cytology showing that the pathological results of these two nodules as papillary thyroid carcinomas.

Figure 3.

A 30-year-old woman was admitted to the hospital for thyroid nodules that had been present for >2 weeks. (a) Two-dimensional ultrasound showing a solid and cystic mixed nodule on the left lobe of the thyroid gland, measuring approximately 10 × 6 × 7 mm³. The solid part exhibits isoechoic echoes with blurred margins and a longitudinal-to-transverse ratio greater than 1. No obvious calcification was observed, and the blood flow signal was not abundant. According to the ACR of Rheumatology classification, it is considered a category 4 nodule. (b) Ultrasound contrast showing uneven enhancement of the nodule on the left lobe, suggesting potential malignancy. (c, hematoxylin and eosin staining ×20) Postoperative pathology indicates papillary thyroid carcinoma. The enhanced part of this nodule was the cystic part in two-dimensional ultrasound examination. Contrast ultrasound suggested that the cystic portion was hypoechoic. The TI-RADS classification of this nodule was corrected to TR5.