Application of contrast-enhanced ultrasound for evaluation of thyroid nodules

Development and validation of a nomogram based on conventional and contrast-enhanced ultrasound for differentiating malignant from benign thyroid nodules

Background

Conventional ultrasound (US) has been routinely used for differential diagnosis of thyroid nodules, but its discriminatory performance remains unsatisfactory. This study aimed to develop and validate a prediction nomogram model based on conventional US and contrast-enhanced ultrasound (CEUS) features for differentiating malignant from benign thyroid nodules.

Methods

A total of 815 thyroid nodules with surgical pathology results and complete conventional US and CEUS data were retrospectively collected from the First People's Hospital of Qinzhou between January 2019 and July 2023. The nodules were grouped into a training cohort (n=571) and a validation cohort (n=244) at a 7:3 ratio. Independent risk factors of malignancy were selected by stepwise multivariate logistic regression analysis, and a prediction nomogram model was subsequently constructed. The diagnostic performance of the model was evaluated by the area under the receiver operating characteristic curve (AUC) in both the training and validation cohorts. The unnecessary fine-needle aspiration biopsy (FNAB) rate was calculated.

Results

Multivariate logistic regression analysis identified irregular margin, aspect ratio >1, and microcalcification from conventional US images, as well as hypo-enhancement intensity and ring enhancement from CEUS images, as independent predictors for malignancy. The AUC, sensitivity, specificity, and accuracy of the prediction nomogram model were 0.947 [95% confidence interval (CI): 0.928-0.966], 90.4%, 88.8%, and 89.8% in the training cohort, and 0.957 (95% CI: 0.928-0.986), 94.5%, 86.4%, and 91.8% in the validation cohort, respectively. Using the prediction model, the unnecessary FNAB rates reduced from 29.6% to 6.1% in the training cohort and from 29.3% to 6.7% in the validation cohort compared to the Chinese Thyroid Imaging Reporting and Data System. Decision curve analysis demonstrated good clinical utility of the nomogram model.

Conclusions

The prediction nomogram model incorporating conventional US and CEUS features could effectively distinguish between malignant and benign thyroid nodules and reduce unnecessary FNAB rates.

Contrast Enhanced Ultrasound: A Quantitative Ultrasound Imaging Mode for the Differential Diagnosis of Benign and Malignant Thyroid Nodules

OBJECTIVE

To compare the qualitative contrast enhanced ultrasound (CEUS) performance with grayscale US with the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) in differentiating benign and malignant thyroid nodules.

METHODS

In this retrospective study, 539 patients with thyroid nodules underwent grayscale US and CEUS. Four predictive models including grayscale US and CEUS sonographic features were constructed using univariable and multivariable logistic regression.

RESULTS

A total of 539 thyroid nodules with confirmed cytological results (350 malignant thyroid nodules) in 539 participants were involved. Four predictive models incorporated nodule features at ACR TI-RADS, CEUS features (enhancement degree, homogeneity and rim enhancement), quantitative CEUS features (peak intensity) and ACR TI-RADS with quantitative PI. In fine-needle aspiration biopsy or pathologic results in thyroid nodules, the highest area under the receiver operating characteristic curve (AUC) was 0.87 (95% CI: 0.84, 0.90) for the ACR TI-RADS with quantitative PI model, which had a significant difference compared to the other three models (p < 0 0.05).

CONCLUSION

TI-RADS with quantitative PI model played a better diagnostic performance in differentiating benign and malignant thyroid nodules.

The Association Between the Thickness of the Hypoechoic Halo of Thyroid Nodules and Thyroid Cancer: A Retrospective Study

RATIONALE AND OBJECTIVES

The association between hypoechoic halos and thyroid cancer in patients with thyroid nodules remains a contentious issue. The objective of this study was to examine the potential correlation between the thickness of hypoechoic halos and the presence of thyroid cancer in individuals with thyroid nodules.

METHODS

The study retrospectively analyzed a cohort of 320 patients with thyroid nodules presenting hypoechoic halos from January 2019 to December 2022. Logistic regression models, both univariate and multivariate, were applied to investigate the association between hypoechoic halo thickness and thyroid cancer, with adjustments for potential confounding variables. Interaction and stratified analyses were conducted to assess the influence of demographic and tumor-specific characteristics, such as age, sex, halo thickness, tumor size, and tumor location, on the relationship between halo thickness and thyroid cancer risk.

RESULTS

After adjusting for multiple covariates, the odds ratios (ORs) (95% confidence intervals (CIs)) of thyroid cancer for participants with a halo thickness ≥1 mm were 3.99 (2.4-6.62), 3.73 (2.09-6.67), and 3.16 (1.61-6.19), compared to those with a thickness <1 mm. The association between thyroid cancer and the thickness of the halo remained stable across different subgroups (all P for interaction > 0.05). The area under the curve (AUC) for the hypoechoic halo in nodules for diagnosing thyroid cancer was 0.821 (95% CI: 0.774-0.868), with the highest sensitivity and specificity observed at a thickness cutoff value of 1.29 mm.

CONCLUSION

Our single-center study on adults reveals a positive correlation between halo thickness and thyroid cancer risk, indicating that halo thickness may potentially serve as a valuable predictor for thyroid cancer incidence.

Role of Ultrasound Elastography and Contrast-Enhanced Ultrasound (CEUS) in Diagnosis and Management of Malignant Thyroid Nodules-An Update

The aim of this paper is to highlight the combined role of ultrasound elastography and contrast-enhanced ultrasound in terms of diagnosis, staging, and follow-up of the post-treatment response. Contrast-enhanced ultrasound (CEUS) and ultrasound elastography are natural extensions of conventional USs that have created new opportunities, facilitating the implementation of multiparametric ultrasounds in the characterization of thyroid nodules, in risk stratification, and in the selection of nodules that request Fine Needle Aspiration (FNA), management, and follow-up of the nodules with indeterminate cytology, evaluation of pre-operative prognostic features, and treatment efficiency.

Ultrasound combined with contrast‑enhanced ultrasound in the diagnosis of primary squamous cell carcinoma of the thyroid: A case report and literature review

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare malignancy with a poor prognosis. Therefore, early diagnosis and treatment are critical to the survival of patients and to improve their quality of life. However, diagnosing this illness is challenging. The present study describes the ultrasound (US) and contrast-enhanced US (CEUS) findings of PSCCT diagnosed in a 69-year-old woman with a rapidly enlarging neck mass. A total thyroidectomy was performed, and the results of postoperative pathology and immunohistochemical tests confirmed the diagnosis of PSCCT. Any other potential primary tumor site was excluded. This case and literature review provide a reliable reference for the diagnosis of PSCCT using US combined with CEUS. Radiologists should increase their understanding of this disease to achieve an early and accurate diagnosis.

The Environmental Impact of Medical Imaging Agents and the Roadmap to Sustainable Medical Imaging

Medical imaging agents, i.e., contrast agents for magnetic resonance imaging (MRI) and radiopharmaceuticals, play a vital role in the diagnosis of diseases. Yet, they mostly contain harmful and non-biodegradable substances, such as per- and polyfluoroalkyl substances (PFAS), heavy metals or radionuclides. As a result of their increasing clinical use, these agents are entering various water bodies and soil, posing risks to environment and human health. Here, the environmental effects of the application of imaging agents are outlined for the major imaging modalities, and the respective chemistry of the contrast agents with environmental implications is linked. Recommendations are introduced for the design and application of contrast agents: the 3Cs of imaging agents: control, change, and combine; and recent approaches for more sustainable imaging strategies are highlighted. This combination of measures should engage an open discussion, inspire solutions to reduce pollution by imaging agents, and increase awareness for the impact of toxic waste related to imaging agents.

Contrast-Enhanced Ultrasound for Diagnosing Thyroid Nodules With Indeterminate Cytology: A Retrospective Study

BACKGROUND

A small number of thyroid nodules cannot be clearly diagnosed using ultrasound-guided fine needle aspiration biopsy. Contrast-enhanced ultrasound (CEUS) has high diagnostic performance for thyroid nodules. We explored the value of CEUS for diagnosing thyroid nodules with indeterminate cytology.

METHODS

Between September 2019 and July 2022, 27,646 patients with thyroid nodule(s) underwent conventional ultrasound (CUS) in our hospital. From these patients, 597 nodules were subjected to CEUS and ultrasound-guided fine needle aspiration biopsy and 116 thyroid nodules with indeterminate cytology diagnose were enrolled in this study. The independent risk factors for predicting malignancy were determined using univariate and multivariate logistic regression analyses. Receiver operating characteristic (ROC) curves were drawn for CUS, CEUS, and CEUS combined with CUS. The area under the curve (AUC) was calculated and compared.

RESULTS

Of the 116 thyroid nodules, 40 (34.5%) were benign and 76 (65.5%) were malignant. Univariate analysis showed that the shape, echogenicity, margin, microcalcification, enhancement intensity, enhancement homogeneity, wash in, and wash out were significantly different between benign and malignant thyroid nodules (all p < 0.05). Multivariate logistic regression analysis showed that taller-than-wide, irregular margin, microcalcification, hypo-enhancement, heterogeneity enhancement, synchronous/slower wash in, and synchronous/slower wash out were independent risk factors for malignancy (all p < 0.05). ROC curve analysis showed that the AUC of CUS and CEUS were 0.769 and 0.848, respectively. No significant difference was observed in the AUC between the two modalities (p > 0.05). However, the AUC (0.934) of the CUS combined with CEUS was significantly higher than that of CEUS or CUS alone (both p < 0.05).

CONCLUSIONS

CEUS is helpful in diagnosing thyroid nodules with indeterminate cytology. CUS combined with CEUS is highly valuable for predicting malignancy.

Sonographic characteristics of thyroid nodules with a Halo

OBJECTIVE

To investigate the sonographic characteristics of thyroid nodules with a halo, explore the value of contrast-enhanced ultrasound (CEUS) combined with fine needle aspiration (FNA) in identifying nodules with a halo, and predict the risk of metastasis by analyzing the pathological features of the halo.

METHODS

A retrospective analysis was conducted on 185 postoperative cases of thyroid nodules accompanied by halos between January 2019 and December 2022. After describing the ultrasound characteristics of the thyroid nodules and their halos, all patients were divided into three groups, the first group (group I = CEUS only) of patients underwent CEUS, the second group (group II = CEUS + FNA) underwent FNA based on the first group, and the third group (group III = FNA only) underwent FNA directly. The CEUS and FNA results were graded using the Chinese Thyroid Imaging Report and Data System (C-TIRADS) and Bethesda Reporting System for Thyroid Cytopathology, respectively. Those graded below C-TIRADS 4b or Bethesda IV were defined as benign, and the results of FNA were referenced when the two methods were combined. The surgical pathology results were used as the gold standard. We plotted working curves to compare the diagnostic efficacy of CEUS and FNA alone and in combination in the diagnosis of thyroid nodules with halos. The pathological features of the halo were analyzed and the number of patients with cervical lymph node metastases was recorded.

RESULTS

One hundred and sixty patients met the requirements. Benign nodules were mainly characterized by a thin (0.75 ± 0.31 mm) and uniform halo with good integrity, while malignant nodules had a thicker (1.48 ± 0.51 mm) halo with uneven and irregular margins (P < 0.05). The sensitivity and specificity were highest when the cutoff value was 1.09 mm, with 76.08% and 84.29%, respectively. The halos of benign nodules were mostly hyper- or iso-enhanced, whereas the halos of malignant nodules were predominantly hypo-enhanced (P < 0.05). The areas under the curve (AUCs) for CEUS, FNA, and CEUS + FNA were 0.751(95% CI = 0.642-0.841), 0.863(95% CI = 0.767-0.929), and 0.918(95% CI = 0.834-0.967), respectively. Cervical lymph node metastasis occurred in only 13 (11.5%) malignant nodes with halos. The primary pathological components of the halo around malignant nodules were almost reactive hyperplastic fibrous tissue.

CONCLUSION

The halo surrounding malignant thyroid nodules is thicker, with uneven and irregular margins, and shows hypo-enhancement on CEUS. Combining CEUS with FNA improves the diagnostic efficacy of thyroid nodules with halos. The reactive hyperplastic fibrous halo may be one of the reasons why malignant nodules are less likely to metastasize.

Diagnostic efficacy of the contrast-enhanced ultrasound thyroid imaging reporting and data system classification for benign and malignant thyroid nodules

Background

The contrasted-enhanced ultrasound thyroid imaging reporting and data system (CEUS TI-RADS) is the first international risk stratification system for thyroid nodules based on conventional ultrasound (US) and CEUS. This study aimed to evaluate the diagnostic efficacy of CEUS TI-RADS for benign and malignant thyroid nodules and to assess the related interobserver agreement.

Methods

The study recruited 433 patients who underwent thyroid US and CEUS between January 2019 and June 2023 at the Affiliated Hospital of Guangdong Medical University. A retrospective analysis of 467 thyroid nodules confirmed by fine-needle aspiration (FNA) and/or surgery was performed. Further, a CEUS TI-RADS classification was assigned to each thyroid nodule based on the CEUS TI-RADS scoring criteria for the US and CEUS features of the nodule. The nodules were grouped based on their sizes as follows: size ≤1 cm, group A; size >1 and ≤4 cm, group B; and size >4 cm, group C. Multivariate logistic regression was used to analyze independent risk factors for malignant thyroid nodules. Pathological assessment was the reference standard for establishing the sensitivity (SEN), specificity (SPE), accuracy (ACC), positive predictive value (PPV), and negative predictive value (NPV) of CEUS TI-RADS in diagnosing malignant thyroid nodules. The area under the curve (AUC) in the receiver operating characteristic (ROC) curve analysis was used to compare the diagnostic efficacy of the scoring system in predicting malignancy in three groups of nodules. The intragroup correlation coefficient (ICC) was adopted to assess the interobserver agreement of the CEUS TI-RADS score.

Results

Out of the 467 thyroid nodules, 262 were malignant and 205 were benign. Logistic regression analysis revealed that the independent risk factors for malignant thyroid nodules included punctate echogenic foci (P<0.001), taller-than-wide shape (P=0.015), extrathyroidal invasion (P=0.020), irregular margins/lobulation (P=0.036), hypoechoicity on US (P=0.038), and hypoenhancement on CEUS (P<0.001). The AUC for the CEUS TI-RADS in diagnosing malignant thyroid nodules was 0.898 for all nodules, 0.795 for group A, 0.949 for group B, and 0.801 for group C, with the optimal cutoff values of the CEUS TI-RADS being 5 points, 6 points, 5 points, and 5 points, respectively. Among these groups of nodules, group B had the highest AUC, with the SEN, SPE, ACC, PPV, and NPV for diagnosing malignant nodules being 95.9%, 88.1%, 92.8%, 92.6%, and 93.2%, respectively. The ICC of the CEUS TI-RADS classification between senior and junior physicians was 0.862 (P<0.001).

Conclusions

In summary, CEUS TI-RADS demonstrated significant efficacy in distinguishing thyroid nodules. Nonetheless, there were variations in its capacity to detect malignant nodules across diverse sizes, and it demonstrate optimal performance in 1- to 4-cm nodules. These findings may serve as important insights for clinical diagnoses.

Radiating blood flow signal: A new ultrasound feature of thyroid carcinoma

OBJECTIVE

To summary radiating blood flow signals and evaluate their diagnostic value in differentiating benign and malignant thyroid nodules.

MATERIALS AND METHODS

We retrospectively recruited consecutive patients undergoing US at 4 hospitals from 2018 to 2022. In a training dataset, the correlations of US features with malignant thyroid nodules were assessed by multivariate logistic analysis. Multivariate logistic regression models involving the ACR TI-RADS score, radiating blood flow signals and their combination were built and validated internally and externally. The AUC with 95% asymptotic normal confidence interval as well as sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) with 95% exact binomial confidence intervals were calculated.

RESULTS

Among 2475 patients (1818 women, age: 42.47 ± 11.57; 657 men, age: 42.16 ± 11.69), there were 3187 nodules (2342 malignant nodules and 845 benign nodules). Radiating blood flow signals were an independent risk factor for diagnosing thyroid carcinoma. In the training set, the AUC of the model using the combination of radiating blood flow signals and the ACR TI-RADS score (0.95 95 % CI: [0.94, 0.97]; P < 0.001) was significantly higher than that of the ACR TI-RADS model (0.91 [0.89, 0.93]). In the two internal validation sets and the external validation set, the AUCs of the combination model were 0.97 [0.96, 0.98], 0.92 [0.88, 0.96], and 0.91 [0.86, 0.95], respectively, and were all significantly higher than that of the ACR TI-RADS score (0.92 [0.90, 0.95], 0.86 [0.81, 0.91], 0.84 [0.79, 0.89]; P < 0.001).

CONCLUSION

Radiating blood flow is a new US feature of thyroid carcinomas that can significantly improve the diagnostic performance vs. the ACR TI-RADS score.

Combining CEUS and ultrasound parameters in thyroid nodule and cancer diagnosis: a TIRADS-based evaluation

Contrast-enhanced ultrasonography (CEUS) has been established as a diagnostic tool for assessing microvascularization, essential for understanding angiogenesis in neoplastic development.

AIM

This study assesses the effectiveness of CEUS as a supplementary tool to TIRADS in enhancing the ultrasound-based diagnosis of thyroid cancer.

METHODS AND MATERIALS

Over one year, 157 nodules in 133 patients, with predominantly solid thyroid nodules, were examined using ultrasound and CEUS and underwent thyroidectomy, allowing for a comparison of ultrasound findings with pathological reports.

RESULTS

Thyroid cancer was identified in 31.21% (49/157) of cases. Significant CEUS high-risk features included inhomogeneous enhancement, enhancement defects, and complete hypoenhancement (AUC 0.818, 0.767, 0.864 respectively). Nodules exhibiting any of these features were classified as high-risk in CEUS. The diagnostic performance of TIRADS improved when combined with CEUS, with AUC increasing from 0.707 to 0.840 and improved sensitivity.

CONCLUSION

The integration of CEUS with TIRADS significantly enhances the diagnostic accuracy and specificity in identifying thyroid cancer. This combination proves to be a more effective method for risk stratification and diagnosis, highlighting the value of CEUS as an adjunctive tool in thyroid cancer evaluation.

The Utility of Contrast-Enhanced Ultrasound (CEUS) in Assessing the Risk of Malignancy in Thyroid Nodules

BACKGROUND

Ultrasonography is a primary method used in the evaluation of thyroid nodules, but no single feature of this method predicts malignancy with high accuracy. Therefore, this paper aims to assess the utility of contrast-enhanced ultrasound (CEUS) in the differential diagnosis of thyroid nodules.

METHODS

The study group comprised 188 adult patients (155 women and 33 men) who preoperatively underwent CEUS of a thyroid nodule classified as Bethesda categories II-VI after fine-needle aspiration biopsy. During the CEUS examination, 1.5 mL of SonoVue contrast was injected intravenously, after which 15 qualitative CEUS enhancement patterns were analysed.

RESULTS

The histopathologic results comprised 65 benign thyroid nodules and 123 thyroid carcinomas. The dominant malignant CEUS features, such as hypo- and heterogeneous enhancement and slow wash-in phase, were evaluated, whereas high enhancement, ring enhancement, and a slow wash-out phase were assessed as predictors of benign lesions. Two significant combinations of B-mode and CEUS patterns were noted, namely, hypoechogenicity with heterogeneous enhancement and non-smooth margins with hypo- or iso-enhancement.

CONCLUSIONS

The preliminary results indicate that CEUS is a useful tool in assessing the risk of malignancy of thyroid lesions. The combination of the qualitative enhancement parameters and B-mode sonographic features significantly increases the method's usefulness.

Clinical prediction models for cervical lymph node metastasis of papillary thyroid carcinoma

PURPOSE

Accurate preoperative diagnosis of lymph node metastasis (LNM) in papillary thyroid carcinoma (PTC) remains an unsolved problem. This study aimed to construct a nomogram and scoring system for predicting LNM based on the clinical characteristics of patients with PTC.

METHODS

1400 patients with PTC who underwent thyroidectomy and lymph node dissection at the First Affiliated Hospital of Sun Yat-sen University were retrospectively enrolled and randomly divided into training and internal testing sets. Furthermore, 692 patients with PTC from three other medical centers were collected as external testing sets. Least absolute shrinkage and selection operator (LASSO) was used to screen the predictors, and a nomogram was constructed. In addition, a scoring system was constructed using 10-fold cross-validation. The performances of the two models were verified among datasets and compared with preoperative ultrasound (US).

RESULTS

Six independent predictors were included in the multivariate logistic model: age, sex, US diagnosis of LNM, tumor diameter, location, and thyroid peroxidase antibody level. The areas under the receiver operating characteristic curve (AUROC) (95% confidence interval) of this nomogram in the training, internal testing, and three external testing sets were 0.816 (0.791-0.840), 0.782 (0.727-0.837), 0.759 (0.699-0.819), 0.749 (0.667-0.831), and 0.777 (0.726-0.828), respectively. The AUROC of the scoring system were 0.810 (0.785-0.835), 0.772 (0.718-0.826), 0.736 (0.675-0.798), 0.717 (0.635-0.799) and 0.756 (0.704-0.808), respectively. The prediction performances were both significantly superior to those of preoperative US (P < 0.001).

CONCLUSION

The nomogram and scoring system performed well in different datasets and significantly improved the preoperative prediction of LNM than US alone.

Development and Validation of a Nomogram Based on Multimodality Ultrasonography Images for Differentiating Malignant from Benign American College of Radiology Thyroid Imaging, Reporting and Data System (TI-RADS) 3-5 Thyroid Nodules

OBJECTIVE

The aim of the work described here was to develop and validate a predictive nomogram based on combined image features of gray-scale ultrasonography (US), elastosonography (ES) and contrast-enhanced US (CEUS) to differentiate malignant from benign American College of Radiology Thyroid Imaging, Reporting and Data System (ACR TI-RADS) 3-5 thyroid nodules.

METHODS

Among 2767 thyroid nodules scanned by CEUS in Xijing Hospital between April 2014 and November 2018, 669 nodules classified as ACR TI-RADS 3-5 were included, with confirmed diagnosis and ES examination. Four hundred fifty-five nodules were set as a training cohort and 214 as a validation cohort. Images were categorized as gray-scale US ACR TI-RADS 3, TI-RADS 4 and TI-RADS 5; ES patterns of ES-1 and ES-2; and CEUS patterns of either heterogeneous hypo-enhancement, concentric hypo-enhancement, homogeneous hyper-/iso-enhancement, no perfusion, hypo-enhancement with sharp margin, island-like enhancement or ring-like enhancement. On the basis of multivariate logistic regression analysis, a predictive nomogram model was developed and validated by receiver operating characteristic curve analysis.

RESULTS

In the training cohort, ACR TI-RADS 4 and 5, ES-2, heterogeneous hypo-enhancement, concentric hypo-enhancement and homogeneous hyper-/iso-enhancement were selected as predictors of malignancy by univariate logistic regression analysis. A predictive nomogram (combining indices of ACR TI-RADS, ES and CEUS) indicated excellent predictive ability for differentiating malignant from benign lesions in the training cohort: area under the receiver operating characteristic curve (AUC) = 0.93, 95% confidence interval (CI): 0.90-0.95. The prediction nomogram model was determined to have a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 0.84, 0.88, 0.91 and 0.81. In the validation cohort, the AUC of the prediction nomogram model was significantly higher than those of the single modalities (p < 0.005) . The AUCs of the validation cohort were 0.93 (95% CI: 0.89-0.96) and 0.93 (95% CI: 0.89-0.97), respectively, for senior and junior radiologists. The prediction nomogram model has a sensitivity, specificity, PPV and NPV of 0.86, 0.87, 0.87 and 0.86.

CONCLUSION

A predictive nomogram model combining ACR TI-RADS, ES and CEUS exhibited potential clinical utility in differentiating malignant from benign ACR TI-RADS 3-5 thyroid nodules.

Clinical value of contrast-enhanced ultrasound quantitative analysis for differentiating thyroid lesions in Hashimoto's thyroiditis patients

Background

The role of quantitative contrast-enhanced ultrasound (CEUS) in the evaluation of thyroid nodules with Hashimoto's thyroiditis (HT) has received little attention.

Methods

This was a retrospective cohort study. We consecutively enrolled 242 patients (49 males, 193 females, average age 52 years) with a combined total of 248 thyroid nodules coexisting with HT who underwent biopsy/resection-proven pathology from December 2016 to June 2021. All patients underwent preoperative ultrasound (US) and CEUS examinations performed by 2 radiologists independently. Quantitative analysis of CEUS using time-intensity curves (TIC) was measured by an expert radiologist from the thyroid intra-nodule and the surrounding parenchyma and their ratios. Receiver operating characteristic (ROC) analysis was performed to evaluate their diagnostic performance.

Results

The patients were divided into the nodular HT (NHT) group (n=42), the papillary thyroid carcinoma (PTC) group (n=154), and the primary thyroid lymphoma (PTL) group (n=52) according to their pathological results. TIC parameters revealed that PTC and PTL showed faster time to peak (TTP) (P=0.044, P=0.049), lower peak intensity (PI) (both P<0.001), and smaller areas under the curve (both P<0.001) than those of NHT. The intra nodule of PTL showed an obviously slower perfusion (ratio =0.90, P<0.001) and lower PI (ratio =0.84, P<0.001) compared with the thyroid parenchyma. TIC improved performance in distinguishing PTL from NHT [area under the curve (AUC): 0.947, 95% confidence interval (CI): 0.903-0.991], but inferior performance in differentiating PTC and NHT (AUC: 0.838, 95% CI: 0.759-0.917).

Conclusions

CEUS quantitative analysis could be valuable in differentiating thyroid malignancies in patients with HT.

Artificial intelligence technology enhances the performance of shear wave elastography in thyroid nodule diagnosis

OBJECTIVE

To investigate the diagnostic value of Artificial Intelligence (AI) in thyroid nodules diseases.

METHODS

This study included 100 patients (100 nodules - 23 benign; 77 malignant) who underwent shear wave elastography (SWE) and AI imaging of nodules prior to biopsy and/or surgery in Zhangjiakou First Hospital from January 2021 to December 2021. The image diagnostic value of AI was analyzed.

RESULTS

Among the 100 patients, there were 77 malignant nodules (77%) and 23 benign nodules (23%). Papillary thyroid carcinoma accounted for 94.8% (74/77) of the malignant nodules, and nodular goiter accounted for 100% of the benign nodules. The overall detection rate of AI+SWE was higher than that of SWE alone (P < 0.05). The accuracy, sensitivity, specificity, negative predictive value, and positive predictive value of AI+SWE were all higher than those of SWE only (P < 0.05). The ROC curve results showed that the area under the curve of AI+SWE in the diagnosis of thyroid nodules was 0.903. This was higher than that of SWE (P < 0.05).

CONCLUSION

SWE+AI is effective in the diagnosis of thyroid nodules, and its sensitivity and specificity are better than those of SWE only.

Joint Segmentation and Differential Diagnosis of Thyroid Nodule in Contrast-Enhanced Ultrasound Images

OBJECTIVE

Microvascular perfusion can be observed in real time with contrast-enhanced ultrasound (CEUS), which is a novel ultrasound technology for visualizing the dynamic patterns of parenchymal perfusion. Automatic lesion segmentation and differential diagnosis of malignant and benign based on CEUS are crucial but challenging tasks for computer-aided diagnosis of thyroid nodule.

METHODS

To tackle these two formidable challenges concurrently, we provide Trans-CEUS, a spatial-temporal transformer-based CEUS analysis model to finish the joint learning of these two challenging tasks. Specifically, the dynamic swin-transformer encoder and multi-level feature collaborative learning are combined into U-net for achieving accurate segmentation of lesions with ambiguous boundary from CEUS. In addition, variant transformer-based global spatial-temporal fusion is proposed to obtain long-distance enhancement perfusion of dynamic CEUS for promoting differential diagnosis.

RESULTS

Empirical results of clinical data showed that our Trans-CEUS model achieved not only a good lesion segmentation result with a high Dice similarity coefficient of 82.41%, but also superior diagnostic accuracy of 86.59%. Conclusion & significance: This research is novel since it is the first to incorporate the transformer into CEUS analysis, and it shows promising results on dynamic CEUS datasets for both segmentation and diagnosis tasks of the thyroid nodule.

The predictive models based on multimodality ultrasonography for the differential diagnosis of thyroid nodules smaller than 10 mm

OBJECTIVE

The objective of this study was to establish a multimodality ultrasound prediction model based on conventional ultrasound (Con-US), shear wave elastography (SWE), and strain elastography (SE) and contrast-enhanced ultrasound (CEUS) and to explore their diagnostic values for thyroid nodules ≤ 10 mm.

METHODS

This retrospective study included 198 thyroid nodules (maximum diameter≤10 mm) in 198 thyroid surgery patients who were examined preoperatively with above-mentioned methods. The pathological findings of the thyroid nodules were used as the gold standard, and there were 72 benign nodules and 126 malignant nodules. The multimodal ultrasound prediction models were developed by logistic regression analysis based on the ultrasound image appearances. The diagnostic efficacy of these prediction models was then compared and internally cross-validated in a fivefold manner.

RESULTS

The specific features on CEUS (enhancement boundary, enhancement direction and decreased nodule area) and the parenchyma-to-nodule strain ratio (PNSR) on SE and SWE ratio were included in the prediction model. The Model one combining American College of Radiology Thyroid Imaging Reporting and Data Systems (ACR TI-RADS) score with PNSR and SWE ratio had the highest sensitivity (92.8%), while the Model three combining TI-RADS score with PNSR, SWE ratio and specific CEUS indicators had the highest specificity, accuracy, and AUC (90.2%,91.4%, and 0.958, respectively).

CONCLUSION

The multimodality ultrasound predictive models effectively improved the differential diagnosis of thyroid nodules smaller than 10 mm.

ADVANCES IN KNOWLEDGE

For the differential diagnosis of thyroid nodules ≤ 10 mm, both ultrasound elastography and CEUS could be effective complements to ACR TI-RADS.

B-mode Ultrasound Characteristics of Thyroid Nodules With High-Benign Probability and Nodules With Risk of Malignancy

INTRODUCTION

Thyroid nodules are commonly found on clinical examination or diagnostic imaging of the neck. Malignant thyroid nodules are increasing worldwide, making thyroid cancer one of the most common endocrine malignancies worldwide. The aim of this study was to determine B-mode ultrasound characteristics of benign thyroid nodules and nodules with risk of malignancy.  Material and methods: This retrospective study was conducted on subjects (n=99) who underwent thyroid ultrasound. Data were retrieved from the Thyroid Digital Image Database of Universidad Nacional de Colombia, a published open-access dataset, in which B-mode ultrasound images were interpreted by expert radiologists providing a complete diagnostic description of thyroid lesions using the Thyroid Imaging Reporting and Data System.

RESULTS

Sponge-like appearance (Pearson Chi-Square 4.6, p=0.02), cystic (Pearson Chi-Square 27.3, p<0.001), isoechoic (Pearson Chi-Square 26, p<0.001), and well-defined (Pearson Chi-Square 13.7, p<0.001) thyroid nodules were more likely to be observed in benign nodules (risk of malignancy <5%). On the other hand, predominately solid (Pearson Chi-Square 5.9, p=0.01), microcalcifications (Pearson Chi-Square 50.7, p<0.001), hypoechoic (Pearson Chi-Square 27.7, p<0.001), irregular shape (Pearson Chi-Square 6.6, p=0.01), and ill-defined (Pearson Chi-Square 8.8, p=0.003) thyroid nodules were more likely to be observed in nodules with risk of malignancy (>5%).

CONCLUSION

Ultrasound characteristics could be used to determine thyroid nodules with risk of malignancy and avoid over-diagnosing nodules with benign features. Further research evaluating the use of multiparametric ultrasound to distinguish between benign thyroid nodules and thyroid nodules with risk of malignancy is required.

Performance of contrast-enhanced ultrasound for lymph node metastasis in papillary thyroid carcinoma: a meta-analysis

BACKGROUND

Papillary thyroid carcinoma is the most common thyroid carcinoma worldwide. Papillary thyroid carcinoma metastasis to the cervical region increases the probability of local or regional recurrence and the requirement for further surgery. Contrast-enhanced ultrasound has been suggested as a possible adjunct diagnostic technique for evaluating papillary thyroid carcinoma metastatic lymph nodes in several studies. This meta-analysis aims to evaluate the diagnostic accuracy of contrast-enhanced ultrasound for cervical lymph nodes metastatic in papillary thyroid carcinoma patients.

METHODS

A search for studies evaluating the role of contrast-enhanced ultrasound for assessing cervical lymph nodes metastatic in papillary thyroid carcinoma patients from January 2000 to May 2022 was performed in PubMed, Embase, OVID, and Web of Science databases. The Quality Assessment of Diagnostic Accuracy Studies 2 evaluated the quality of the studies. All analyses were performed using Review Manager 5.3 and Stata 17.0.

RESULTS

A total of seven articles were finally included in this study. Perfusion type, enhancement homogeneous, hilum absent, and perfusion defect were involved in the meta-analysis as the standard of contrast-enhanced ultrasound, among which, perfusion type showed the best diagnostic performance. The pooled estimated sensitivity, specificity, positive likelihood, negative likelihood ratio, and diagnostic odds ratio of perfusion type in contrast-enhanced ultrasound for detecting lymph node metastasis were 0.95 (0.91, 0.97), 0.87 (0.69, 0.96), 7.51 (2.80, 20.14), 0.06 (0.03, 0.10), and 124.17 (42.78, 360.46), respectively. Heterogeneity was moderate.

CONCLUSION

The perfusion type in contrast-enhanced ultrasound has good diagnostic performance for cervical lymph nodes metastasis in papillary thyroid carcinoma patients.

Ultrasound imaging in thyroid nodule diagnosis, therapy, and follow-up: Current status and future trends

Ultrasound, the primary imaging modality in thyroid nodule management, suffers from drawbacks including: high inter- and intra-observer variability, limited field-of-view and limited functional imaging. Developments in ultrasound technologies are taking place to overcome these limitations, including three-dimensional-Doppler, -elastography, -nodule characteristics-extraction, and novel machine-learning algorithms. For thyroid ablative treatments and biopsies, perioperative use of three-dimensional ultrasound opens a new field of research. This review provides an overview of the current and future applications of ultrasound, and discusses the potential of new developments and trends that may improve the diagnosis, therapy, and follow-up of thyroid nodules.

Clinical Diagnostic Application of Contrast-Enhanced Ultrasound in Focal Lesions of the Salivary Glands

OBJECTIVES

To evaluate the clinical diagnostic value of contrast-enhanced ultrasound (CEUS) for focal benign and malignant lesions of the salivary glands, as well as for common benign lesions.

METHODS

A total of 91 patients with focal lesions of the salivary glands were included in this study. In this study, CEUS was used to study the differential diagnosis of focal benign and malignant lesions of the salivary gland and the most common benign tumors, that is, pleomorphic adenoma (PA) and adenolymphoma.

RESULTS

The differences between focal benign and malignant lesions in the salivary glands were statistically significant (P < .05) in terms of qualitative CEUS indicators, enhancement pattern, enhancement homogeneity, enhancement margin, and enhanced lesion size, whereas the differences were not statistically significant (P > .05) in terms of wash-in and wash-out pattern, enhancement degree. Blurred margins and increased size of the lesion after enhancement are two CEUS features independently associated with focal malignant lesions of the salivary gland. The differences between salivary gland PA and adenolymphoma were statistically significant (P < .05) in terms of wash-in pattern, enhancement degree, enhancement homogeneity, and enhancement pattern, but not in terms of wash-out pattern, enhancement margin, and enhanced lesion size (P > .05).

CONCLUSIONS

As an economical, convenient, and safe imaging method, CEUS has important clinical value in distinguishing benign and malignant salivary glands.

The Value of Chinese Thyroid Imaging Report and Data System Combined With Contrast-Enhanced Ultrasound Scoring in Differential Diagnosis of Benign and Malignant Thyroid Nodules

OBJECTIVES

To explore the diagnostic value of contrast-enhanced ultrasound (CEUS) combined with the Chinese Thyroid Imaging Reporting and Data System (C-TIRADS) for differentiation of benign and malignant thyroid nodules.

METHODS

A retrospective analysis of the conventional ultrasound and CEUS data of 388 nodules in 355 patients who had undergone thyroid nodule resection was conducted. All nodules had clear pathological results. The CEUS observation indexes included the enhancement degree in the arterial phase (no enhancement, scant punctate-linear enhancement, mild enhancement, moderate enhancement, and high enhancement) and wash-out patterns (rapid wash-out, slow wash-out, and isochronous wash-out). Chi-square test between groups and receiver operating characteristic curves (ROC) were used to determine the malignant (+1 point) and benign (-1 point) observation indexes that were statistically significant for the differentiation between benign and malignant thyroid nodules. The CEUS and C-TIRADS malignant and benign indexes were combined to score and draw the ROC curve, which was compared with the ROC curve scored by C-TIRADS alone to compare the diagnostic efficacy of the two methods for differentiating between benign and malignant thyroid nodules.

RESULTS

Among the CEUS observation indexes, mild enhancement and rapid wash-out were malignant indexes, while isochronous wash-out was a benign index. The best diagnostic cut-off value for the differentiation of benign and malignant thyroid nodules using the C-TIRADS score and the C-TIRADS and CEUS combined score (C-TIRADS + CEUS score) was 2. The sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) of the two methods were 79.97, 75.48, 82.9, 70.5%, and 89.7, 72.9, 83.3, 82.5%, respectively. The area under the curve values were 0.840 and 0.877 (P < .001), respectively.

CONCLUSIONS

The CEUS feature of mild enhancement in the arterial phase and rapid wash-out pattern are suggestive of malignancy and isochronous wash-out pattern is suggestive of benignity. The C-TIRADS + CEUS score has a higher value for distinguishing benign from malignant thyroid nodules than the C-TIRADS score alone.

A Practical CEUS Thyroid Reporting System for Thyroid Nodules

Background The role of contrast-enhanced US (CEUS) in reducing unnecessary biopsies of thyroid nodules has received little attention. Purpose To construct and externally validate a thyroid imaging reporting and data system (TI-RADS) based on nonenhanced US and CEUS to stratify the malignancy risk of thyroid nodules. Materials and Methods This retrospective study evaluated 756 patients with 801 thyroid nodules who underwent nonenhanced US, CEUS, and fine-needle aspiration and received a final diagnosis from January 2018 to December 2019. Qualitative US features of the thyroid nodules were analyzed with univariable and multivariable logistic regression to construct a CEUS TI-RADS. The CEUS TI-RADS was validated with use of internal cross-validation and external validation. Results A total of 801 thyroid nodules in 590 female (mean age, 44 years ± 13) and 166 male (mean age, 47 years ± 13 [SD]) patients were included. Independent predictive US features included nodule composition at CEUS, echogenicity, nodule shape, nodule margin, echogenic foci, extrathyroidal extension, enhancement direction, peak intensity, and ring enhancement. The CEUS TI-RADS showed a higher area under the receiver operating characteristic curve of 0.93 (95% CI: 0.92, 0.95; P < .001 in comparison with all other systems), a biopsy yield of malignancy of 66% (157 of 239 nodules), and an unnecessary biopsy rate of 34% (82 of 239 nodules). In the external validation, the area under the receiver operating characteristic curve, biopsy yield of malignancy, and unnecessary biopsy rate of CEUS TI-RADS were 0.89 (95% CI: 0.84, 0.92), 61% (65 of 106 nodules), and 39% (41 of 106 nodules) for the first external validation set and 0.90 (95% CI: 0.85, 0.94), 57% (56 of 99 nodules), and 43% (43 of 99 nodules) for the second external validation set. Conclusion A contrast-enhanced US (CEUS) thyroid imaging reporting and data system was created with thyroid nodule malignancy risk stratification according to the simplified regression coefficients of nonenhanced US and qualitative features of CEUS. Clinical trials registration no. ChiCTR2000028712 Published under a CC BY 4.0 license. Online supplemental material is available for this article.

Systematic review and meta-analysis: diagnostic value of different ultrasound for benign and malignant thyroid nodules

BACKGROUND

Conventional ultrasound and contrast-enhanced ultrasound (CEUS) are commonly used in the diagnosis of benign and malignant thyroid nodules. However, the value of the two methods in the diagnosis of benign and malignant thyroid nodules remains controversial.

METHODS

PubMed, Medline, EBSCO, Science Direct, Cochrane Library, China National Knowledge Infrastructure (CNKI) database and manual journal retrieval were searched from January 2000 to January 2022, to include research on conventional ultrasound or CEUS in the diagnosis of benign and malignant thyroid nodule related clinical studies. Meta-analysis was conducted using RevMan5.3 and Stata Corp to analyze the sensitivity and specificity of conventional ultrasound and CEUS in the diagnosis of benign and malignant thyroid nodules with 95% confidence interval (CI) as indicators. Heterogeneity of the results was evaluated by Q test and I2 in RevMan5.3. Deek's method was used to evaluate publication bias.

RESULTS

A total of 1,378 nodules were included in 11 literatures, including 535 malignant thyroid nodules and 843 benign thyroid nodules. Heterogeneity tests conducted for CEUS diagnostic sensitivity of the 6 included literatures indicated that there was no heterogeneity among the study groups [Q=2.05, degree of freedom (df) =5.00, I2=0.00%, P=0.84]. The combined sensitivity was 0.87, with 95% confidence interval (CI): 0.82 to 0.90. Heterogeneity tests on the diagnostic specificity of CEUS of the six included literatures suggested that there was heterogeneity among the different study groups (Q=14.27, df =5.00, I2=64.96%, P=0.01). The combined specificity was 0.84 (95% CI: 0.78 to 0.89). Heterogeneity tests performed on the sensitivity of five conventional ultrasound diagnosis articles revealed that there was heterogeneity among different study groups (Q=13.62, df =4.00, I2=70.64%, P=0.01). The combined sensitivity was 0.86 (95% CI: 0.78 to 0.92). Heterogeneity tests on the specificity of conventional ultrasound diagnosis in five included literatures indicated that there was heterogeneity among different study groups (Q=16.94, df =4.00, I2=76.39%, P=0.00). The combined specificity was 0.84 (95% CI: 0.75 to 0.90). There was no bias in the included literature.

DISCUSSION

The sensitivity of CEUS in the diagnosis of benign and malignant thyroid nodules was slightly higher than that of conventional ultrasound, which provides a reference for the clinical diagnosis of benign and malignant thyroid nodules.

2021 Korean Thyroid Imaging Reporting and Data System and Imaging-Based Management of Thyroid Nodules: Korean Society of Thyroid Radiology Consensus Statement and Recommendations

Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1-2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.

Exploring the Value of Radiomics Features Based on B-Mode and Contrast-Enhanced Ultrasound in Discriminating the Nature of Thyroid Nodules

Background

With the improvement of ultrasound imaging resolution and the application of various new technologies, the detection rate of thyroid nodules has increased greatly in recent years. However, there are still challenges in accurately diagnosing the nature of thyroid nodules. This study aimed to evaluate the clinical application value of the radiomics features extracted from B-mode ultrasound (B-US) images combined with contrast-enhanced ultrasound (CEUS) images in the differentiation of benign and malignant thyroid nodules by comparing the diagnostic performance of four logistic models.

Methods

We retrospectively collected and ultimately included B-US images and CEUS images of 123 nodules from 123 patients, and then extracted the corresponding radiomics features from these images respectively. Meanwhile, a senior radiologist combined the thyroid imaging reporting and data system (TI-RADS) and the enhancement pattern of the ultrasonography to make a graded diagnosis of the malignancy of these nodules. Next, based on these radiomics features and grades, logistic regression was used to help build the models (B-US radiomics model, CEUS radiomics model, B-US+CEUS radiomics model, and TI-RADS+CEUS model). Finally, the study assessed the diagnostic performance of these radiomics features with a comparison of the area under the curve (AUC) of the receiver operating characteristic curve of four logistic models for predicting the benignity or malignancy of thyroid nodules.

Results

The AUC in the differential diagnosis of the nature of thyroid nodules was 0.791 for the B-US radiomics model, 0.766 for the CEUS radiomics model, 0.861 for the B-US+CEUS radiomics model, and 0.785 for the TI-RADS+CEUS model. Compared to the TI-RADS+CEUS model, there was no statistical significance observed in AUC between the B-US radiomics model, CEUS radiomics model, B-US+CEUS radiomics model, and TI-RADS+CEUS model (P>0.05). However, a significant difference was observed between the single B-US radiomics model or CEUS radiomics model and B-US+CEUS radiomics model (P<0.05).

Conclusion

In our study, the B-US radiomics model, CEUS radiomics model, and B-US+CEUS radiomics model demonstrated similar performance with the TI-RADS+CEUS model of senior radiologists in diagnosing the benignity or malignancy of thyroid nodules, while the B-US+CEUS radiomics model showed better diagnostic performance than single B-US radiomics model or CEUS radiomics model. It was proved that B-US radiomics features and CEUS radiomics features are of high clinical value as the combination of the two had better diagnostic performance.

Performance of Contrast-Enhanced Ultrasound in Thyroid Nodules: Review of Current State and Future Perspectives

Ultrasound has been established as a baseline imaging technique for thyroid nodules. The main advantage of adding CEUS is the ability to assess the sequence and intensity of vascular perfusion and hemodynamics in the thyroid nodule, thus providing real-time characterization of nodule features, considered a valuable new approach in the determination of benign vs. malignant nodules. Original studies, reviews and six meta-analyses were included in this article. A total of 624 studies were retrieved, and 107 were included in the study. As recognized for thyroid nodule malignancy risk stratification by US, for acceptable accuracy in malignancy a combination of several CEUS parameters should be applied: hypo-enhancement, heterogeneous, peripheral irregular enhancement in combination with internal enhancement patterns, and slow wash-in and wash-out curve lower than in normal thyroid tissue. In contrast, homogeneous, intense enhancement with smooth rim enhancement and "fast-in and slow-out" are indicative of the benignity of the thyroid nodule. Even though overlapping features require standardization, with further research, CEUS may achieve reliable performance in detecting or excluding thyroid cancer. It can also play an operative role in guiding ablation procedures of benign and malignant thyroid nodules and metastatic lymph nodes, and providing accurate follow-up imaging to assess treatment efficacy.

Value of Conventional Ultrasonography with Contrast-Enhanced Ultrasonography in the Differential Diagnosis of Partial Cystic Thyroid Nodules

The value of contrast-enhanced ultrasonography (CEUS) in the diagnosis of malignant partial cystic thyroid nodules (PCTNs) remains unclear. Thus, in the present study, the data of patients with pathologically proven PCTNs who underwent CEUS in the Chinese PLA General Hospital from January 2016 to February 2019 were retrospectively reviewed, and the imaging characteristics of benign and malignant PCTNs were compared. A total of 177 PCTNs were enrolled in this study, including 58 (32.7%) malignant nodules and 119 (67.2%) benign nodules. Six characteristics significantly differed between malignant PCTNs and benign PCTNs in univariate comparison: position of the solid portion (χ² = 17.937, p < 0.001), microcalcifications (χ² = 81.382, p < 0.001), boundaries (χ² = 45.486, p < 0.001), echogenicity (χ² = 11.152, p = 0.004), intensity of enhancement (χ² = 40.656, p < 0.001) and uniformity of enhancement (χ² = 19.933, p < 0.001). Among these, microcalcifications, boundaries, position of the solid portion, and uniformity of enhancement were independent risk factors in the multivariate comparison. A logistic regression model for predicting benign and malignant PCTNs was established with a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 89.0% (95% confidence interval [CI]: 0.788-0.961), 91.0% (95% CI: 0.830-0.946), 81.0% (95% CI: 0.715-0.881), 95.0% (95% CI: 0.892-0.974) and 90.0% (95% CI: 0.844-0.938), respectively. The area under the receiver operating characteristic curve was 0.967 (95% CI: 0.944-0.990), which was significantly higher than that of conventional ultrasound only (0.747, 95% CI: 0.663-0.831, Z = 2.090, p = 0.0366). CEUS can be used in the diagnosis of PCTNs, and the four characteristics of malignant PCTNs proven by our study were microcalcifications, unclear boundaries, eccentric distributions of the solid parts and heterogeneous enhancement.

Clinical value of contrast-enhanced ultrasonography in focal hypoechogenic lesions of thyroid

OBJECTIVE

The objectives of this study were to analyze the accuracy of contrast-enhanced ultrasonography (CE-US) in diagnosing focal hypoechogenic lesions of the thyroid (FHLT), and to explore the clinical value of CE-US in the diagnosis of FHLT.

METHODS

Patients undergoing CE-US and ultrasound-guided fine needle aspiration (US-FNA) of FHLT at First Hospital of China Medical University between January 2017 and December 2018 were selected for the study; this included patients with papillary thyroid carcinoma (PTC), subacute thyroiditis (SAT) and focal Hashimoto thyroiditis (FHT). All patients underwent color Doppler ultrasonography (CD-US) after which thyroid image reporting and data system (TI-RADS) grading were done. Then, each patient underwent CE-US and US-FNA. The results of the CE-US were analyzed using descriptive statistics. The cytopathological results from the US-FNAs were the gold standard used to confirm the diagnoses.

RESULTS

A total of 56 patients were selected for the study. In the PTC group (n = 16), grading was as follows: TI-RADS4a, n = 3; TI-RADS4b, n = 12; and TI-RADS4c, n = 1. More patients with PTC showed heterogeneous hypoenhancement (n = 15) than heterogeneous isoenhancement (n = 1) on CE-US. In the SAT group (n = 24), grading was as follows: TI-RADS3, n = 1; TI-RADS4a, n = 18; TI-RADS4b, n = 5. Fewer patients with SAT showed heterogeneous hypoenhancement (n = 2) than heterogeneous isoenhancement (n = 22) on CE-US. In the FHT group (n = 16), grading was as follows: TI-RADS3, n = 1; TI-RADS4a, n = 11; TI-RADS4b, n = 4. Of those in the FHT group, one patient showed heterogeneous isoenhancement, one patient showed heterogeneous hypoenhancement, and 14 showed uniform isoenhancement on CE-US. The diagnostic accuracy of CD-US alone differed significantly from that of CD-US + CE-US (p < 0.05).

CONCLUSION

CE-US has a high diagnostic accuracy for FHLT and can be used to identify PTC, SAT, and FHT.

Hierarchical Temporal Attention Network for Thyroid Nodule Recognition Using Dynamic CEUS Imaging

Contrast-enhanced ultrasound (CEUS) has emerged as a popular imaging modality in thyroid nodule diagnosis due to its ability to visualize vascular distribution in real time. Recently, a number of learning-based methods are dedicated to mine pathological-related enhancement dynamics and make prediction at one step, ignoring a native diagnostic dependency. In clinics, the differentiation of benign or malignant nodules always precedes the recognition of pathological types. In this paper, we propose a novel hierarchical temporal attention network (HiTAN) for thyroid nodule diagnosis using dynamic CEUS imaging, which unifies dynamic enhancement feature learning and hierarchical nodules classification into a deep framework. Specifically, this method decomposes the diagnosis of nodules into an ordered two-stage classification task, where diagnostic dependency is modeled by Gated Recurrent Units (GRUs). Besides, we design a local-to-global temporal aggregation (LGTA) operator to perform a comprehensive temporal fusion along the hierarchical prediction path. Particularly, local temporal information is defined as typical enhancement patterns identified with the guidance of perfusion representation learned from the differentiation level. Then, we leverage an attention mechanism to embed global enhancement dynamics into each identified salient pattern. In this study, we evaluate the proposed HiTAN method on the collected CEUS dataset of thyroid nodules. Extensive experimental results validate the efficacy of dynamic patterns learning, fusion and hierarchical diagnosis mechanism.

Contrast-Enhanced Ultrasound in the Differential Diagnosis and Risk Stratification of ACR TI-RADS Category 4 and 5 Thyroid Nodules With Non-Hypovascular

Objective

This study aims to investigate the value of contrast-enhanced ultrasound (CEUS) in the differential diagnosis and risk stratification of ACR TI-RADS category 4 and 5 thyroid nodules with non-hypovascular.

Methods

From January 2016 to December 2019 in our hospital, 217 ACR TI-RADS category 4 and 5 nodules with non-hypovascular in 210 consecutive patients were included for a derivation cohort. With surgery and/or fine-needle aspiration (FNA) as a reference, conventional ultrasound (US) features and CEUS features were analyzed. Multivariate logistic regression analysis was used to screen the independent risk factors and establish a risk predictive model. Between January 2020 and March 2021, a second cohort of 100 consecutive patients with 101 nodules were included for an external validation cohort. The model was converted into a simplified risk score and was validated in the validation cohort. The area under the receiver operating characteristic curves (AUC) were used to assess the models’ diagnostic performance.

Results

Micro-calcification, irregular margin, earlier wash-out, centripetal enhancement, and absence of ring enhancement were independent risk factors and strongly discriminated malignancy in the derivation cohort (AUC = 0.921, 95% CI 0.876–0.953) and the validation cohort (0.900, 0.824–0.951). There was no significant difference (P = 0.3282) between the conventional US and CEUS in differentiating malignant non-hypovascular thyroid nodules, but a combination of them (the predictive model) had better performance than the single method (all P <0.05), with a sensitivity of 87.0%, specificity of 86.2%, and accuracy of 86.6% in the derivation cohort. The risk score based on the independent risk factors divided non-hypovascular thyroid nodules into low-suspicious (0–3 points; malignancy risk <50%) and high-suspicious (4–7 points; malignancy risk ≥ 50%), the latter with nodule ≥10mm was recommended for FNA. The risk score showed a good ability of risk stratification in the validation cohort. Comparing ACR TI-RADS in screening suitable non-hypovascular nodules for FNA, the risk score could avoid 30.8% benign nodules for FNA.

Conclusions

CEUS is helpful in combination with conventional US in differentiating ACR TI-RADS category 4 and 5 nodules with non-hypovascular. The risk score in this study has the potential to improve the diagnosis and risk stratification of non-hypovascular thyroid nodules.

Update on ACR TI-RADS: Successes, Challenges, and Future Directions, From the AJR Special Series on Radiology Reporting and Data Systems

The American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) is an ultrasound-based risk stratification system (RSS) for thyroid nodules that was released in 2017. Since publication, research has shown that ACR TI-RADS has a higher specificity than other RSSs and reduces the number of unnecessary biopsies of benign nodules compared with other systems by 19.9-46.5%. The risk of missing significant cancers using ACR TI-RADS is mitigated by the follow-up recommendations for nodules that do not meet criteria for biopsy. In practice, after a nodule's ultrasound features have been enumerated, the ACR TI-RADS points-based approach leads to clear management recommendations. Practices seeking to implement ACR TI-RADS must engage their radiologists in understanding how the system addresses the problems of thyroid cancer overdiagnosis and unnecessary surgeries by reducing unnecessary biopsies. This review compares ACR TI-RADS to other RSSs and explores key clinical questions faced by practices considering its implementation. We also address the challenge of reducing interobserver variability in assigning ultrasound features. Finally, we highlight emerging imaging techniques and recognize the ongoing international effort to develop a system that harmonizes multiple RSSs, including ACR TI-RADS.

Contrast-Enhanced Ultrasound in the Differential Diagnosis of Primary Thyroid Lymphoma and Nodular Hashimoto's Thyroiditis in a Background of Heterogeneous Parenchyma

Objective

To investigate the diagnostic performance of contrast-enhanced ultrasound (CEUS) in the differentiation of primary thyroid lymphoma (PTL) and nodular Hashimoto’s thyroiditis (NHT) in patients with background of heterogeneous diffuse Hashimoto’s thyroiditis (HT).

Methods

Sixty HT patients with 64 thyroid nodules (31 PTL and 33 NHT) who had undergone CEUS examination were included in this study. With histopathological results as the reference, we evaluated the imaging features of each nodule on both conventional ultrasonography (US) and CEUS. Quantitative CEUS parameters including peak intensity (PI), time to peak (TTP), and area under the time–intensity curve (AUC) were gathered in the nodule and background parenchyma. The ratio indexes of theses parameters were calculated by the ratio of the lesion and the corresponding thyroid parenchyma. Logistic regression and receiver operating characteristic (ROC) curves analyses of valuable US indicators were further preformed to evaluate the diagnostic capability of CEUS in discrimination of PTL and NHT.

Results

Among all the observed US imaging features and CEUS parameters, 10 indicators showed significant differences between PTL and NHT (all P < 0.05). All the significant indicators were ranked according to the odds ratios (ORs). Eight of them were CEUS associated including imaging features of enhancement pattern, degree, homogeneity, and quantification parameters of PI, AUC, ratios of PI, AUC, and TTP, while indicators on conventional US, including vascularity and size ranked the last two with ORs less than 3. The five single CEUS parameters showed good diagnostic performance in diagnosis of PTL with areas under ROC curves of 0.72–0.83 and accuracies of 70.3–75.0%. The combination of CEUS imaging features and the ratios of PI, AUC, and TTP demonstrated excellent diagnostic efficiency and achieved area under ROC curve of 0.92, which was significantly higher than any of the five single parameters (all P < 0.05), with a sensitivity of 83.9%, specificity of 87.9%, and accuracy of 85.9%.

Conclusions

CEUS is an efficient diagnostic tool in the differential diagnosis of PTL and NHT for patients with diffuse HT. Conjoint analysis of CEUS imaging features and quantification parameters could improve the diagnostic values.

Contrast-enhanced ultrasound of the small organs in children

In pediatric and adult populations, intravenous contrast-enhanced ultrasound (CEUS) remains off-label for imaging of organs other than the liver and heart. This limited scope inhibits potential benefits of the new modality from a more widespread utilization. Yet, CEUS is potentially useful for imaging small organs such as the thyroid gland, lymph nodes, testes, ovaries and uterus, with all having locations and vasculature favorable for this type of examination. In the adult population, the utility of CEUS has been demonstrated in a growing number of studies for the evaluation of these small organs. The aim of this article is to present a review of pediatric CEUS of the thyroid gland, lymph nodes, testes, ovaries and uterus as well as to draw from the adult literature indications for possible applications in children.

Clinical applications of Doppler ultrasonography for thyroid disease: consensus statement by the Korean Society of Thyroid Radiology

Doppler ultrasonography (US) is widely used for the differential diagnosis of thyroid nodules, metastatic cervical lymph nodes in patients with thyroid cancer, and diffuse parenchymal disease, as well as for guidance in various US-guided procedures, including biopsy and ablation. However, controversies remain regarding the appropriate use and interpretation of Doppler US. Therefore, the Korean Society of Thyroid Radiology organized a taskforce to develop a consensus statement on the clinical use of Doppler US for thyroid disease. The review and recommendations in this article are based on a comprehensive analysis of the current literature and the consensus of experts.

US-Guided Radiofrequency Ablation for Low-Risk Papillary Thyroid Microcarcinoma: Efficacy and Safety in a Large Population

OBJECTIVE

To evaluate the efficacy and safety of radiofrequency ablation (RFA) for low-risk papillary thyroid microcarcinoma (PTMC) in a large population.

MATERIALS AND METHODS

Cases of 152 biopsy-proven PTMCs from 133 patients who had undergone RFA for PTMC between May 2008 and January 2017 were included in this study. All patients were either of high surgical risk or refused to undergo surgery. They were followed up for at least 6 months after initial RFA. Ultrasonography (US) and computed tomography were performed to evaluate the PTMC and the presence of neck metastasis before treatment. RFA was conducted using an internally cooled thyroid-dedicated electrode system. Follow-up US was performed at 1 week, and 2, 6, and 12 months, after the initial RFA, and then at every 6-12 months. We evaluated serial changes of ablated tumors, newly developed cancers, lymph node (LN) or distant metastasis and complications.

RESULTS

Complete disappearance was found in 91.4% (139/152) of ablated tumors. Among the 13 tumors in patients who did not show complete disappearance, no tumor displayed any regrowth of the residual ablated lesion during the follow-up period. The mean follow-up period was 39 months. During the follow-up period, there were no local recurrence, no LN or distant metastasis, and no newly developed thyroid cancers. No patients were referred to surgery. The overall complication rate was 3% (4/133) of patients, including one voice change. There were no life-threatening complications or procedure-related deaths.

CONCLUSION

Our results suggest that RFA is an effective and safe option for treating low-risk PTMC patients who are of high surgical risk or refuse surgery.

TI-RADS Diagnostic Performance: Which Algorithm is Superior and How Elastography and 4D Vascularity Improve the Malignancy Risk Assessment

Given the increased prevalence of thyroid nodules in the general population (~50%), the real challenge resides in correctly recognizing the suspicious ones. This study proposes to compare four important Thyroid Imaging and Reporting Data Systems (TI-RADS) and evaluate the contribution of elastography and 4D Color Doppler assessment of vascularity in estimating the risk of malignancy. In the study, 133 nodules with histopathological examination were included. Of these, 35 (26.31%) proved to be malignant. All nodules were classified using the four selected systems and our proposed improved score. The American College of Radiology (ACR) and EU TI-RADS had good sensitivity (94.28%, 97.14%) and NPV (93.33%, 95.83%), but fairly poor specificity (31.81%, 23.46%) and PPV (35.48%, 31.19%), with an accuracy of 42.8% and 45.8%, respectively. Horvath TI-RADS had better accuracy of 66.9% and somewhat improved specificity (62.24%), but poorer sensitivity (80%). Russ' French TI-RADS includes elastography in the risk assessment strategy. This classification proved superior in all aspects (Se: 91.42%, Sp:82.65%, NPV:96.42%, PPV:65.30%, and Acc of 84.96%). The mean strain ratio (SR) value for malignant lesions was 5.56, while the mean SR value for benign ones was significantly lower, 2.54 (p < 0.05). It also correlated well with the response variable: histopathological result (p < 0.001). Although, adding 4D vascularity to the French score generated a similar calculated accuracy and from a statistical point of view, the parameter itself proved beneficial for predicting the malignancy risk (p < 0.001) and may add important knowledge in uncertain situations. Advanced ultrasound techniques definitely improved the risk estimation and should be used more extensively.

Differential diagnosis of thyroid nodules through a combination of multiple ultrasonography techniques: A decision-tree model

The present study aimed to establish a decision tree (DT) model by combining the parameters of conventional gray-scale ultrasonography (US), elastosonography (ES), color Doppler US (CDUS) and contrast-enhanced US (CEUS) for the differential diagnosis of thyroid nodules. A single-center, retrospective study of 321 thyroid nodules was conducted. For 222 nodules, parameters of conventional gray-scale US, CDUS, ES and CEUS were evaluated using univariate logistic regression. Factors for with P<0.10 were further assessed using multivariate logistic regression. Significant factors (P<0.05) were used to establish a DT. The diagnostic accuracy of this DT was then evaluated by its application to the other 99 nodules. After univariate logistic analysis, factors including gender, number of nodules and diffuse disease were excluded, due to P>0.10. The results of multivariate logistic analysis determined that the following factors were required for the DT: Extent of blood flow determined by CDUS (P=0.002), area ratio determined by ES (P=0.033), peak phase patterns determined by CEUS (P<0.001) and micro-calcification determined by conventional gray-scale US (P=0.015). When compared to the pathological or cytological results of 99 nodules, the resulting DT had a sensitivity of 98.6%, specificity of 80.1%, positive predictive value of 93.5% and negative predictive value of 95.5%. These results suggested that a DT combining conventional gray-scale US, ES, CDUS and CEUS may be helpful for differentiating between types of thyroid nodules.

Diagnostic Accuracy of Contrast-Enhanced Ultrasonography in Papillary Thyroid Microcarcinoma Stratified by Size

We explored the diagnostic accuracy of ultrasonography (US) in papillary thyroid microcarcinoma (PTMC), studying nodular growths according to size via 3-D color Doppler US (3-DCDUS) and contrast-enhanced US (CEUS). A total of 109 patients undergoing CEUS and surgery of thyroid nodules at the First Hospital of China Medical University between January 2017 and December 2018 were selected for the study, including 77 with post-operative pathologically confirmed PTMC (test group) and 32 with nodular goiter (controls). All nodules were ≤1.0 cm in maximum diameter. After 3-DCDUS, each patient underwent Thyroid Imaging Reporting and Data System (TI-RADS) grading. In both groups, receiver operating characteristic curve analysis of anteroposterior (AP) nodule diameters was conducted, establishing a cutpoint for probable malignancy by CEUS. In the test group (n = 77), grading was as follows: TI-RADS 4a, 23; TI-RADS 4b, 40; TI-RADS 4c, 14. More patients had heterogeneous enhancement or hypo-enhancement (n = 55) than uniform hyper-enhancement or uniform iso-enhancement (n = 22) by contrast-enhanced ultrasonography (CEUS). Control group (n = 32) grading was as follows: TI-RADS 3, 1; TI-RADS 4, 21; TI-RADS 4b, 10. Fewer patients had heterogeneous enhancement or hypo-enhancement (n = 12) than uniform hyper-enhancement or uniform iso-enhancement (n = 20) by CEUS. The diagnostic accuracy of 3-DCDUS or CEUS differed significantly from that of 3-DCD-US + CEUS (p < 0.05), whereas 3-DCDUS and CEUS performed similarly (p > 0.05). At AP diameters of 0.66 cm, the Youden index for diagnosing malignancy by CEUS was maximal. When nodules below this threshold were excluded, both CEUS and 3-DCDUS + CEUS improved significantly in diagnostic accuracy (p < 0.05). CEUS is useful in determining the status (benign vs. malignant) of thyroid nodules, with significantly better accuracy at AP diameters ≥0.66 cm.