The diagnostic accuracy of contrast-enhanced ultrasound for the differentiation of benign and malignant thyroid nodules: A PRISMA compliant meta-analysis

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.

Quantitative parameters of contrast-enhanced ultrasound effectively promote the prediction of cervical lymph node metastasis in papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC), the most common endocrine tumor, often spreads to cervical lymph nodes metastasis (CLNM). Preoperative diagnosis of CLNM is important when selecting surgical strategies. Therefore, we aimed to explore the effectiveness of quantitative parameters of contrast-enhanced ultrasound (CEUS) in predicting CLNM in PTC. We retrospectively analyzed 193 patients with PTC undergoing conventional ultrasound (CUS) and CEUS. The CUS features and quantitative parameters of CEUS were evaluated according to PTC size ≤ 10 or > 10 mm, using pathology as the gold standard. For the PTC ≤ 10 mm, microcalcification and multifocality were significantly different between the CLNM (+) and CLNM (-) groups (both P < 0.05). For the PTC > 10 mm, statistical significance was noted between the two groups with respect to the margin, capsule contact, and multifocality (all P < 0.05). For PTC ≤ 10 mm, there was no significant difference between the CLNM (+) and CLNM (-) groups in all quantitative parameters of CEUS (all P > 0.05). However, for PTC > 10 mm, the peak intensity (PI), mean transit time, and slope were significantly associated with CLNM (all P < 0.05). Multivariate analysis showed that PI > 5.8 dB was an independent risk factor for predicting CLNM in patients with PTC > 10 mm (P < 0.05). The area under the curve of PI combined with CUS (0.831) was significantly higher than that of CUS (0.707) or PI (0.703) alone in the receiver operator characteristic curve analysis (P < 0.05). In conclusion, PI has significance in predicting CLNM for PTC > 10 mm; however, it is not helpful for PTC ≤ 10 mm.

Thyroid ultrasound and its ancillary techniques

Ultrasound (US) of the thyroid has been used as a diagnostic tool since the late 1960s. US is the most important imaging tool for diagnosing thyroid disease. In the majority of cases a correct diagnosis can already be made in synopsis of the sonographic together with clinical findings and basal thyroid hormone parameters. However, the characterization of thyroid nodules by US remains challenging. The introduction of Thyroid Imaging Reporting and Data Systems (TIRADSs) has improved diagnostic accuracy of thyroid cancer significantly. Newer techniques such as elastography, superb microvascular imaging (SMI), contrast enhanced ultrasound (CEUS) and multiparametric ultrasound (MPUS) expand diagnostic options and tools further. In addition, the use of artificial intelligence (AI) is a promising tool to improve and simplify diagnostics of thyroid nodules and there is evidence that AI can exceed the performance of humans. Combining different US techniques with the introduction of new software, the use of AI, FNB as well as molecular markers might pave the way for a completely new area of diagnostic accuracy in thyroid disease. Finally, interventional ultrasound using US-guided thermal ablation (TA) procedures are increasingly proposed as therapy options for benign as well as malignant thyroid diseases.

2023 European Thyroid Association Clinical Practice Guidelines for thyroid nodule management

With the widespread use of sensitive imaging techniques, which include neck visualization, a conspicuous number of thyroid nodules emerge and demand attention. Most lesions are benign, asymptomatic, and do not warrant treatment. In the case of cancer diagnosis, most are small, intrathyroidal and indolent neoplasms that can safely be managed conservatively. There is a pronounced need for more cost-effective, risk-adapted approaches to the management of this highly prevalent condition, taking the wishes of the patient into consideration. Thus, the present guidelines aim at providing a clinical practice guide for the initial workup and the subsequent management of adult individuals harboring thyroid nodules. Importantly, these guidelines are not intended to cover the management of thyroid malignancy. The manuscript and the specific recommendations were developed by reconciling the best available research evidence with the knowledge and clinical experience of the panelists and updating aspects of a number of previous European Thyroid Association guidelines.

Development and validation of a dynamic nomogram based on conventional ultrasound and contrast-enhanced ultrasound for stratifying the risk of central lymph node metastasis in papillary thyroid carcinoma preoperatively

Purpose

The aim of this study was to develop and validate a dynamic nomogram by combining conventional ultrasound (US) and contrast-enhanced US (CEUS) to preoperatively evaluate the probability of central lymph node metastases (CLNMs) for patients with papillary thyroid carcinoma (PTC).

Methods

A total of 216 patients with PTC confirmed pathologically were included in this retrospective and prospective study, and they were divided into the training and validation cohorts, respectively. Each cohort was divided into the CLNM (+) and CLNM (-) groups. The least absolute shrinkage and selection operator (LASSO) regression method was applied to select the most useful predictive features for CLNM in the training cohort, and these features were incorporated into a multivariate logistic regression analysis to develop the nomogram. The nomogram's discrimination, calibration, and clinical usefulness were assessed in the training and validation cohorts.

Results

In the training and validation cohorts, the dynamic nomogram (https://clnmpredictionmodel.shinyapps.io/PTCCLNM/) had an area under the receiver operator characteristic curve (AUC) of 0.844 (95% CI, 0.755-0.905) and 0.827 (95% CI, 0.747-0.906), respectively. The Hosmer-Lemeshow test and calibration curve showed that the nomogram had good calibration (p = 0.385, p = 0.285). Decision curve analysis (DCA) showed that the nomogram has more predictive value of CLNM than US or CEUS features alone in a wide range of high-risk threshold. A Nomo-score of 0.428 as the cutoff value had a good performance to stratify high-risk and low-risk groups.

Conclusion

A dynamic nomogram combining US and CEUS features can be applied to risk stratification of CLNM in patients with PTC in clinical practice.

Value of CEUS features in diagnosing thyroid nodules with halo sign on B-mode ultrasound

BACKGROUND

The results of halo sign in the differential diagnosis of thyroid nodules were conflicting, and the value of contrast-enhanced ultrasound (CEUS) in characterization of thyroid nodules with halo has not been fully evaluated. This study was therefore designed to investigate the value of contrast-enhanced ultrasound features in the differential diagnosis of thyroid nodules with halo sign on B-mode ultrasound.

MATERIAL AND METHODS

Seventy-four consecutive thyroid nodules with halo sign on B-mode ultrasound were pathologically confirmed by surgery or fine needle aspiration, including 43 benign and 31 malignant lesions. All these lesions underwent pre-operative CEUS examination. The CEUS features, including enhanced time, enhanced intensity and homogeneity, and presence of enhancing ring, were compared between benign and malignant ones.

RESULTS

Enhanced intensity was significant different between benign and malignant lesions with halo. Hypo-enhancement was more frequently detected in malignant nodules than that in benign ones, compared with iso-enhancement and hyper-enhancement (p = 0.013, and = 0.014, respectively). Detection rate of high-enhancing ring was significantly higher in benign nodules than that in malignant group (p = 0.001). While in nodules > 10 mm, only high-enhancing ring was the distinguishing feature between benign and malignant nodules.

CONCLUSIONS

Enhanced intensity and high-enhancing ring may be helpful in the differential diagnosis of thyroid nodules with halo sign on B-mode ultrasound.

SFE-AFCE-SFMN 2022 Consensus on the management of thyroid nodules: Initial work-up for thyroid nodules

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons, but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). This section deals with the initial work-up for thyroid nodules in adult patients, including clinical and biological evaluation, standardized ultrasound characterization and EU-TIRADS-based nodule selection for fine-needle aspiration biopsy. Indications for thyroid core-biopsies or open surgical biopsies and for cross-sectional imaging of the neck and upper chest are also mentioned.

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.

Thyroid Nodule Characterization: How to Assess the Malignancy Risk. Update of the Literature

Ultrasound (US) is the first imaging modality for thyroid parenchyma evaluation. In the last decades, the role of ultrasound has been improved with the introduction of new US software, such as contrast-enhanced ultrasound (CEUS) and US-elastography (USE). USE is nowadays recognized as an essential part of the multiparametric ultrasound (MPUS) examination, in particular for the indeterminate thyroid nodule with possible fine-needle aspiration cytology (FNAC) number reduction; even if further and larger studies are needed to validate it. More controversial is the role of CEUS in thyroid evaluation, due to its high variability in sensitivity and specificity. Semi-automatic US systems based on the computer-aided diagnosis (CAD) system are producing interesting results, especially as an aid to less experienced operators. New knowledge on the molecular mechanisms involved in thyroid cancer is allowing practitioners to identify new genomic thyroid markers that could reduce the number of "diagnostic" thyroidectomies. We have therefore drawn up an updated representation of the current evidence in the literature for thyroid nodule multiparametric ultrasound (MPUS) evaluation with particular regard to USE, the US CAD system and CEUS.

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.

Deep Neural Architectures for Contrast Enhanced Ultrasound (CEUS) Focal Liver Lesions Automated Diagnosis

Computer vision, biomedical image processing and deep learning are related fields with a tremendous impact on the interpretation of medical images today. Among biomedical image sensing modalities, ultrasound (US) is one of the most widely used in practice, since it is noninvasive, accessible, and cheap. Its main drawback, compared to other imaging modalities, like computed tomography (CT) or magnetic resonance imaging (MRI), consists of the increased dependence on the human operator. One important step toward reducing this dependence is the implementation of a computer-aided diagnosis (CAD) system for US imaging. The aim of the paper is to examine the application of contrast enhanced ultrasound imaging (CEUS) to the problem of automated focal liver lesion (FLL) diagnosis using deep neural networks (DNN). Custom DNN designs are compared with state-of-the-art architectures, either pre-trained or trained from scratch. Our work improves on and broadens previous work in the field in several aspects, e.g., a novel leave-one-patient-out evaluation procedure, which further enabled us to formulate a hard-voting classification scheme. We show the effectiveness of our models, i.e., 88% accuracy reported against a higher number of liver lesion types: hepatocellular carcinomas (HCC), hypervascular metastases (HYPERM), hypovascular metastases (HYPOM), hemangiomas (HEM), and focal nodular hyperplasia (FNH).

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.

"Double-Flash": An Innovative Method to Diagnose Papillary Thyroid Microcarcinomas

The aim of the study was to investigate the diagnostic ability of an innovative method called "Double-Flash" during contrast-enhanced ultrasound (CEUS) examination in papillary thyroid microcarcinomas. A total of 43 nodules measuring <10 mm and with definite pathology confirmed by surgery or fine-needle aspiration biopsy (FNAB) were included in this study. The bottom of "Flash" was pressed in the 40th and 60th seconds, respectively, defined as "Double-Flash." The curve of reperfusion was evaluated and the diagnostic value of "Double-Flash" was compared with that of CEUS. Pathologic results obtained by surgery or FNAB revealed there were 27 malignant and 16 benign nodules. The sensitivity, specificity and accuracy of CEUS were 70.0%, 53.8% and 65.1%. With "Double-Flash," the sensitivity, specificity and accuracy were 92.3%, 82.3% and 88.4%, respectively. The difference was statistically significant. Higher diagnostic ability is obtained with "Double-Flash." The parameter based on the new method could improve the diagnostic performance of quantitative diagnosis in CEUS. The change in the perfusion curve after "Flash" may be a strong indicator of malignancy.

Application of ultrasonic shear wave elastography and contrast-enhanced ultrasound in the differential diagnosis of patients with benign and malignant thyroid lesions

Background

Thyroid nodules are a common thyroid disorder. The aim of the present study was to observe the application value of ultrasonic shear wave elastography (SWE) and contrast-enhanced ultrasound (CEUS) in the differential diagnosis of patients with benign and malignant thyroid lesions.

Methods

Eighty-two patients with thyroid nodules (96 thyroid nodules) at our hospital were enrolled. All patients underwent ultrasonic SWE and CEUS examination. With surgical pathology as the gold standard, the Young's modulus, CEUS imaging features, and quantitative parameters were compared between the benign and malignant groups. The diagnostic efficiency of SWE, CEUS, and their combination was analyzed by receiver-operating characteristic curve (ROC).

Results

The average of the Young's modulus in the malignant group was significantly higher than that of the benign group (P<0.05). There were significant differences in the CEUS images of nodules between the benign and malignant groups in terms of boundary conditions, morphology, perfusion intensity, homogeneous enhancement, and perfusion defects (P<0.05), while there were no significant difference in initial increase time, peak intensity, time to peak, and area under the curve (P>0.05). The curve sharpness in the benign group was significantly lower than that of the malignant group (P<0.05). ROC analysis found that the diagnostic sensitivity and specificity of SWE, CEUS, and their combination were 90.1% and 81.6%, 67.8% and 75.4%, and 97.3% and 71.5%, respectively.

Conclusions

Compared with CEUS, the sensitivity and specificity of SWE were relatively higher in the differential diagnosis of benign and malignant thyroid lesions, and a combination of both can improve the diagnostic sensitivity of SWE alone to a certain extent.

Preoperative Prediction of Cervical Lymph Node Metastasis in Papillary Thyroid Carcinoma via Conventional and Contrast-Enhanced Ultrasound

OBJECTIVES

To investigate the independent risk factors for cervical lymph node metastasis (CLNM) in patients with papillary thyroid carcinoma (PTC) and establish a prediction model via conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS).

METHODS

A total of 275 patients with single PTC, who were admitted to our hospital from January 2016 to December 2018, were enrolled in this study. The clinical characteristics and features of the tumor on conventional US and CEUS were retrospectively analyzed. A binary logistic regression model was established, and the diagnostic efficacy of conventional US and CEUS was compared.

RESULTS

The binary logistic regression analysis showed that age younger than 38 years, size of 10.0 mm or greater, solid composition, peak of the nodule interior of 28.3750 or greater, and area under the curve (AUC) of the peripheral ring of less than 3.2500 were independent risk factors of CLNM (P < .05, for all). Prediction model: Logit (p) = -4.135 + 1.040 (age) + 1.920 (size) + 1.769 (composition) + 1.230 (peak of nodule interior) + 0.812 (AUC of peripheral ring). The model positively predicted CLNM at a value of L > -0.199. The AUC, sensitivity, and negative predictive value of the receiver operating characteristic curve for the model were 0.727, 71.7%, and 75.2%, respectively, which were significantly higher than those of conventional US (Z = -2.403; P = .016; Z = -5.330; P < .001; and Z = -2.390; P = .017). The specificity of the model was 73.7%, which was lower than that of conventional US (Z = 3.508; P < .001).

CONCLUSIONS

The preoperative prediction model established via conventional US and CEUS may be helpful to evaluate CLNM in patients with PTC and determine the appropriate treatment options.

Contrast-enhanced ultrasound for the differential diagnosis of thyroid nodules: An updated meta-analysis with comprehensive heterogeneity analysis

The diagnostic accuracy of contrast-enhanced ultrasound (CEUS) for distinguishing malignant thyroid nodules from benign thyroid nodules remains controversial. This meta-analysis was performed to evaluate the overall diagnostic value of CEUS for the characterization of thyroid nodules. Relevant studies were identified by searching PubMed, Embase and the Cochrane Library until August 1th 2019 to assess the overall diagnostic accuracy of CEUS. 37 eligible studies were included in the present meta-analysis. The pooled sensitivity, specificity, positive likelihood rate, negative likelihood rate and diagnostic odds ratio of CEUS were 0.87, 0.83, 5.38, 0.17 and 38.94, respectively, with the AUC of 0.9263. Subgroup analysis showed the heterogeneity was greatly reduced in small nodules group (≤ 1 cm) (I2 = 0.0%), while heterogeneity was still observed in the group of variable sizes group (I2 = 69.5%). However, meta-regression analysis revealed that only diagnostic criterion was the major source of heterogeneity (p = 0.0259). The risk of publication bias was negligible (p = 0.35). CEUS exhibited high accuracy for the identification of thyroid nodules and might provide additional perfusion information for the current US imaging reporting systems.