First experience of comparisons between two different shear wave speed imaging systems in differentiating malignant from benign thyroid nodules

Impact of Region-of-Interest Size on the Diagnostic Performance of Shear Wave Elastography in Differentiating Thyroid Nodules

This study investigated the impact of different region-of-interest (ROI) sizes (Max, 1 mm, and 2 mm) on shear wave elastography (SWE) in differentiating between malignant and benign thyroid nodules. The study cohort comprised 129 thyroid nodules (50 malignant, 79 benign) and 78 normal subjects. Diagnostic efficacy was assessed through pairwise comparisons of area under the curve (AUC) values in receiver operating characteristic analysis by using DeLong's test. Our results indicated significant differences in all SWE elasticity metrics between the groups, with malignant nodules exhibiting higher values than benign nodules (p < 0.05). Smaller ROIs (1 and 2 mm) were found to outperform the max ROI in terms of diagnostic accuracy, particularly for the Emax and Emin elasticity metrics. Emax(1mm) had the highest diagnostic accuracy, with an AUC of 0.883, sensitivity of 74.0%, and specificity of 86.1%. This study underscores the significant influence of ROI size selection on the diagnostic performance of SWE, offering valuable insights for future research and clinical applications in thyroid nodule assessment.

Combined Shear Wave Elastography and EU TIRADS in Differentiating Malignant and Benign Thyroid Nodules

Although multimodal ultrasound approaches have been suggested to potentially improve the diagnosis of thyroid cancer; the diagnostic utility of the combination of SWE and malignancy-risk stratification systems remains vague due to the lack of standardized criteria. The purpose of the study was to assess the diagnostic value of the combination of grey scale ultrasound assessment using EU TIRADS and shear wave elastography. 121 patients (126 nodules−81 benign; 45 malignant) underwent grey scale ultrasound and SWE imaging of nodules between 0.5 cm and 5 cm prior to biopsy and/or surgery. Nodules were analyzed based on size stratifications: <1 cm (n = 43); 1−2 cm (n = 52) and >2 cm (n = 31) and equivocal cytology status (n = 52), and diagnostic performance assessments were conducted. The combination of EU TIRADS with SWE using the SD parameter; maintained a high sensitivity and significantly improved the specificity of sole EU TIRADS for nodules 1−2 cm (SEN: 72.2% vs. 88.9%, p > 0.05; SPEC: 76.5% vs. 55.9%, p < 0.01) and >2 cm (SEN: 71.4% vs. 85.7%, p > 0.05; SPEC: 95.8% vs. 62.5%, p < 0.01). For cytologically-equivocal nodules; the combination with the SWE minimum parameter resulted in a significant reduction in sensitivity with increased specificity (SEN: 60% vs. 80%; SPEC: 83.4% vs. 37.8%; all p < 0.05). SWE in combination with EU TIRADS is diagnostically efficient in discriminating nodules > 1 cm but is not ideal for discriminating cytologically-equivocal nodules.

SuperSonic shear imaging for the differentiation between benign and malignant thyroid nodules: a meta-analysis

PURPOSE

To assess the diagnostic value of SuperSonic shear imaging (SSI) for the differentiation between benign and malignant thyroid nodules through meta-analysis.

METHODS

Online database searches were performed on PubMed, EMBASE, the Cochrane Library, and the Web of Science until 31 July 2021. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess the quality of the included studies. Three measures of diagnostic test performance were used to examine the value of SSI, including the summary area under the receiver operating characteristic curve (AUROC), the summary diagnostic odds ratio (DOR), and the summary sensitivity and specificity. Heterogeneity was explored using meta-regression and subgroup analyses.

RESULTS

Finally, 21 studies with 3376 patients were included in this study. There were a total of 4296 thyroid nodules, in which 1806 malignant nodules and 2490 benign ones were involved. Thyroid nodules exhibited a malignancy rate of 42.0% (range 5.6-79.8%), 95.1% of which were of papillary variant. SSI showed a summary sensitivity of 74% [95% confidence interval (CI) 67-79%], specificity of 82% (95% CI 77-87%) and AUROC of 0.85 (95% CI 0.82-0.88) for the differentiation between benign and malignant thyroid nodules. The summary positive likelihood ratio (LR), negative LR, and DOR were 4.2 (95% CI 3.3-5.3), 0.32 (95% CI 0.26-0.40), and 13 (95% CI 9-18), respectively.

CONCLUSIONS

SSI showed high accuracy in the diagnostic differentiation between benign and malignant thyroid nodules and can be served as a noninvasive and important adjunct for thyroid nodule evaluation.

Comparison of thyroid nodule FNA rates recommended by ACR TI-RADS, Kwak TI-RADS and ATA guidelines

OBJECTIVES

To compare the differences among the thyroid imaging reporting and data system (TI-RADS) proposed by American College of Radiology (ACR TI-RADS), TI-RADS proposed by Kwak (Kwak TI-RADS), and American Thyroid Association (ATA) guidelines in the specificity, sensitivity and the unnecessary FNA rate (the UFR, the false positive rate) of recommended fine needle aspiration (FNA), and to observe the changes of the UFR in the KwakTI-RADS and ATA guidelines with the recommended FNA nodule size threshold.

METHODS

The specificities, sensitivities and UFRs of recommended FNA in the ACR TI-RADS, ATA guidelines and Kwak TI-RADS were calculated and compared. The nodule sizes for recommended FNA of ATA guidelines and Kwak TI-RADS were systematically varied to establish new FNA thresholds. The specificities, sensitivities and UFRs of recommended FNA under the new models were calculated and compared to those in the ACR TI-RADS.

RESULTS

For all thyroid nodules, the UFRs in the ACR TI-RADS, ATA guidelines and Kwak TI-RADS were 26.3%, 47.4% and 40.0%, respectively. The UFR in the ACR TI-RADS was lower than that in the others, and the specificity of recommended FNA in the ACR TI-RADS(73.7%) was higher than that in the others (all P < 0.001), but the sensitivity of recommended FNA in the ACR TI-RADS(89.3%) was lower than that in the others (all P < 0.001). When nodule sizes threshold of the recommended FNA for ATA guidelines Intermediate Suspicion, Low Suspicion, and Very Low Suspicion, and Kwak TI-RADS grade 4b and 4a were gradually increased, the UFRs gradually decreased.

CONCLUSIONS

The UFRs of FNA recommended by the Kwak TI-RADS and ATA guidelines were higher than that of the ACR TI-RADS, and were affected by the recommended FNA nodule size threshold.

Influence of lesion size on shear wave elastography in the diagnosis of benign and malignant thyroid nodules

In shear wave elastography (SWE) studies, the optimal cutoff value of Young's modulus for the diagnosis of benign and malignant thyroid nodules varies greatly, which affects the clinical application of the method. The objective of this study was to evaluate the influence of thyroid nodule size on the clinical diagnostic efficacy of SWE. A total of 356 thyroid nodules of 280 patients were divided into three groups according to size (Group A: ≤ 1 cm; Group B: 1-2 cm; Group C: ≥ 2 cm). SWE was used to measure the maximum Young's modulus (Emax) values of all thyroid nodules. Receiver operating characteristic (ROC) curves were drawn with pathological results as the gold standard. For all nodules, the optimal cutoff value of Emax in SWE for diagnosing malignant thyroid nodules was 36.2 kPa. The sensitivity and specificity were 76.5% and 78.4%, respectively. Groups A, B, and C had different optimal Emax cutoff values of 33.7 kPa, 37.7 kPa, and 55.1 kPa, respectively. The area under the ROC curve (AUC) values of Groups A, B, and C (0.844, 0.886, and 0.935, respectively) were all greater than the values for all lesions (0.830). The specificity values of Groups A, B, and C (86.4%, 82.6%, and 88.2%, respectively) were all increased, and the sensitivity values of Groups B and C (89.7% and 96.4%, respectively) were also increased compared with the values for all lesions. Thyroid nodule size affects the optimal Emax cutoff value of SWE. We suggest that different cutoff values be used to diagnose benign and malignant thyroid nodules according to lesion size.

Evaluation of thyroid nodules by shear wave elastography: a review of current knowledge

PURPOSE

Shear wave elastography (SWE), as a tool for diagnosing thyroid malignancy, has gathered considerable attention during the past decade. Diverging results exist regarding the diagnostic performance of thyroid SWE.

METHODS

A comprehensive literature review of thyroid SWE was conducted using the terms "Thyroid" and "shear wave elastography" in PubMed.

RESULTS

The majority of studies found SWE promising for differentiating malignant and benign thyroid nodules on a group level, whereas results are less convincing on the individual level due to huge overlap in elasticity indices. Further, there is lack of consensus on the optimum outcome reflecting nodule elasticity and the cut-off point predicting thyroid malignancy. While heterogeneity between studies hinders a clinically meaningful meta-analysis, the results are discussed in a clinical perspective with regard to applicability in clinical practice as well as methodological advantages and pitfalls of this technology.

CONCLUSION

Technological as well as biological hindrances seem to exist for SWE to be clinically reliable in assessing benign and malignant thyroid nodules. Structural heterogeneity of thyroid nodules in combination with operator-dependent factors such as pre-compression and selection of scanning plane are likely explanations for these findings. Standardization and consensus on the SWE acquisition process applied in future studies are needed for SWE to be considered a clinically reliable diagnostic tool for detection of thyroid cancer.

SWE combined with ACR TI-RADS categories for malignancy risk stratification of thyroid nodules with indeterminate FNA cytology

OBJECTIVES

To compare the diagnostic efficacy of shear wave elastography (SWE) comnined with ACR TI-RADS categories for malignancy risk stratification of thyroid nodules with interminate FNA cytology.

METHODS

The clinical data, sonographic features, ACR TI-RADS grading and shear wave elastography images of 193 patients of surgical pathologically proven thyroid nodules with interminate FNA cytology were retrospectively analyzed. The diagnostic efficacy of ACR TI-RADS categories, the maximum Young's modulus (Emax) of SWE and the combination of the two were calculated respectively.

RESULTS

The ROC curves were drawn using surgical pathology results as the gold standard. The ROC curves indicated that the cut-off value of ACR TI-RADS and Emax of SWE was TR5 and 41.2 kPa respectively, and the area under the ROC curve (AUC) was 0.864 (95% CI: 0.879-0.934) and 0.858 (95% CI: 0.796-0.920) respectively. The diagnostic sensitivity, specificity and accuracy of ACR TI-RADS was 81.4% (127/156), 84.8% (31/37), and 81.9% (158/193), respectively. That of SWE Emax was 80.8% (126/156), 78.4% (29/37), and 80.3% (155/193), respectively. After SWE combined with ACR TI-RADS, the sensitivity, specificity and accuracy was 94.2% (147/156), 75.7% (28/37), and 90.7% (175/193), respectively.

CONCLUSIONS

ACR TI-RADS classification system and shear wave elastography had high diagnostic efficacy for thyroid nodules with interminate FNA cytology. The combination of the two could improve diagnostic sensitivity and accuracy, and could help to differentiate benign and malignant thyroid nodules with interminate FNA cytology.

Evaluation of thyroid micro-carcinoma using shear wave elastography: Initial experience with qualitative and quantitative analysis

PURPOSE

We aimed to assess the diagnostic performance of shear wave elastography (SWE) to assess perinodular stiffness before fine needle aspiration (FNA) of thyroid nodules with a maximum diameter of 1.0 cm.

METHOD

This retrospective study included 69 thyroid nodules in 68 patients who underwent conventional ultrasound and SWE before ultrasound-guided FNA or surgical excision. The stiffness of perinodular regions was evaluated using wave patterns. Quantitative SWE features were also assessed. Sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve were calculated using conventional ultrasound and conventional ultrasound with SWE.

RESULTS

Of the 69 nodules, 57(82.6 %)were malignant and 12(17.4 %)were benign. The maximum elastic modulus (Emax) was higher for malignant nodules(P＜ 0.05). There was no significant difference in mean elastic modulus or minimum elastic modulus between malignant and benign nodules. The Emax≥ 28.2 kPa was the best cut-off value for malignant base on receiver operating curve. Perinodular stiffness was significantly greater for malignant nodules compared with benign nodules according to shear wave patterns. Compared with ultrasound alone, the rate of benign lesions recommended for FNA decreased from 75.0 % (9/12) to 25.0 % (3/12) with conventional ultrasound plus SWE.

CONCLUSION

SWE provides quantitative and qualitative information when used with conventional ultrasound. SWE has the potential to reduce the number of unnecessary FNA procedures.

Comparisons of ACR TI-RADS, ATA guidelines, Kwak TI-RADS, and KTA/KSThR guidelines in malignancy risk stratification of thyroid nodules

OBJECTIVE

To compare the diagnostic performance and the unnecessary biopsy rates for recommending fine needle aspiration (FNA) of Thyroid Imaging Reporting and Data Systems proposed by American College of Radiology (ACR TI-RADS), American Thyroid Association (ATA) guidelines, TI-RADS proposed by Kwak (Kwak TI-RADS), and Korean Thyroid Association/Korean Society of Thyroid Radiology (KTA/KSThR) guidelines for malignancy risk stratification of thyroid nodules (TNs).

METHODS

The study included 1271 TNs whose cytologic results or surgical pathologic findings were available. Ultrasound images of these TNs were retrospectively reviewed and categorized according to the four guidelines. The diagnostic performances and the unnecessary biopsy rates for recommending FNA of the four guidelines were evaluated.

RESULTS

After multivariate analysis, the most significant independent predictor for malignancy was hypoechogenicity/marked hypoechogenicity (OR: 9.37, 95% CI: 5.40-16.26) (P < 0.001) among the suspicious ultrasound images features. For all nodules and two subgroups (i.e. nodules <10 mm group and nodules ≥10 mm group), ACR TI-RADS demonstrated higher specificities (all P < 0.05) and lower sensitivities (all P < 0.001) than the other guidelines. In the all nodules group and the nodules<10 mm group, ACR TI-RADS and Kwak TI-RADS had higher Azs than the other guidelines (all P < 0.01). The unnecessary biopsy rates for recommending FNA of ACR TI-RADS in the all nodules (≥10 mm) group and the subgroup (10∼19 mm) were all lower than those of the others guidelines (P < 0.001 for all). For the subgroup (≥20 mm), the unnecessary biopsy rate of ACR was lower than that of ATA guidelines and KTA/KSThR guidelines (P < 0.001).

CONCLUSIONS

The four guidelines have good diagnostic efficiency in differentiating TNs. ACR TI-RADS and Kwak TI-RADS have better diagnostic performance than the other guidelines in the all nodules group and the nodules<10 mm group. Considering the comprehensive diagnostic efficacy and unnecessary biopsy rate, ACR TI-RADS is a more desirable classification guideline in clinical practice.

Diagnostic Accuracy Evaluation of Two-Dimensional Shear Wave Elastography in the Differentiation Between Benign and Malignant Thyroid Nodules: Systematic Review and Meta-analysis

OBJECTIVES

To evaluate two-dimensional (2D) shear wave elastography (SWE) performance as an independent predictor of malignancy in the diagnostic differentiation of thyroid nodules (TNs), including subgroup analyses of different manufacturers and respective cutoffs points.

METHODS

The online databases MEDLINE (PubMed), Embase, and the Cochrane Library were searched for articles using 2D SWE in TN evaluation. After good-quality relevant thyroid-specific articles were selected, the main data, plus their sensitivity and specificity, were tabulated. Summary receiver operating characteristic curves were generated to verify the accuracy of data obtained from 3 manufactures. A meta-analysis was performed to evaluate whether clinical recommendations can be improved by the use of 2D SWE to differentiate TNs.

RESULTS

The sensitivity and specificity parameters of 2D SWE for the differentiation between benign and malignant TNs according to different instruments were, respectively, as follows: Toshiba SWE (Toshiba Medical Systems, Tochigi, Japan), 0.77 (95% confidence interval [CI], 0.70-0.83) and 0.76 (95% CI, 0.72-0.81); Virtual Touch tissue imaging and quantification (Siemens Medical Solutions, Mountain View, CA), 0.72 (95% CI, 0.67-0.77) and 0.81 (95% CI, 0.78-0.84); and SuperSonic SWE (SuperSonic Imagine, Aix-en-Provence, France), 0.63 (95% CI, 0.59-0.66) and 0.81 (95% CI, 0.79-0.83). The summary receiver operating characteristic curves showed the following area under the curve syntheses: Toshiba SWE, 0.84 (Q* = 0.7707); Virtual Touch tissue imaging and quantification, 0.85 (Q* = 0.7809); and SuperSonic SWE, 0.88 (Q* = 0.8102). Positive and negative predictive values varied, respectively, from 16% to 94% and 29% to 100%, considering all included articles. The overall accuracy ranged from 53% to 93%.

CONCLUSIONS

Two-dimensional SWE is a relevant and an important tool that supports ultrasound in clinical practice in the diagnostic differentiation between benign and malignant TNs.

The Role of Shear Wave Elastography in the Discrimination Between Malignant and Benign Thyroid Nodules

Background:

Grayscale ultrasound (US) is the most common imaging modality for the assessment of thyroid nodules.

Objective:

This research aimed to assess the value of using the elasticity index (EI), obtained using shear wave elastography (SWE), to discriminate between malignant and benign thyroid nodules.

Materials and methods:

A total of 86 patients (94 distinct thyroid nodules) were operated on at Vietnam National Cancer Hospital from June 2018 to June 2019. Comparisons of the grayscale ultrasound (US) findings and the EI values between the benign and malignant groups were performed using the Chi-square test and Student’s t-test, respectively. The discrimination abilities of EI were determined through receiver operating characteristic (ROC) curve analysis, with the computation of optimal cut-off points.

Results:

The EI values of the benign and malignant groups were 37.6 ± 26.1 kPa and 105.4 ± 48.8 kPa, respectively. The area under the ROC curve (AUROC) value for discrimination between groups based on EI values was 0.889 when using an optimal cut-off point of 74.5 kPa, which resulted in a sensitivity of 74.3% and a specificity of 90%. Logistic multivariate regression analysis found that EI and microcalcification were significant factors for the discrimination between groups, with an odds ratio (OR): 1.487 [95% confidence interval (95% CI): 1.124–1.968, p = 0.005] and OR: 12.119 (95% CI: 2.031–72.323, p = 0.006), respectively. Combining grayscale US imaging with SWE can increase the specificity of the diagnosis but does not increase the accuracy.

Conclusion:

SWE can be helpful for predicting the malignancy of thyroid nodules, although the accuracy of this method is only moderate.

Reappraisal of shear wave elastography as a diagnostic tool for identifying thyroid carcinoma

Thyroid nodular disease is common, but predicting the risk of malignancy can be difficult. In this prospective study, we aimed to assess the diagnostic accuracy of shear wave elastography (SWE) in predicting thyroid malignancy. Patients with thyroid nodules were enrolled from a surgical tertiary unit. Elasticity index (EI) measured by SWE was registered for seven EI outcomes assessing nodular stiffness and heterogeneity. The diagnosis was determined histologically. In total, 329 patients (mean age: 55 ± 13 years) with 413 thyroid nodules (mean size: 32 ± 13 mm, 88 malignant) were enrolled. Values of SWE region of interest (ROI) for malignant and benign nodules were highly overlapping (ranges for SWE-ROImean: malignant 3-100 kPa; benign 4-182 kPa), and no difference between malignant and benign nodules was found for any other EI outcome investigated (P = 0.13-0.96). There was no association between EI and the histological diagnosis by receiver operating characteristics analysis (area under the curve: 0.51-0.56). Consequently, defining a cut-off point of EI for the prediction of malignancy was not clinically meaningful. Testing our data on previously proposed cut-off points revealed a low accuracy of SWE (56-80%). By regression analysis, factors affecting EI included nodule size >30 mm, heterogeneous echogenicity, micro- or macrocalcifications and solitary nodule. In conclusion, EI, measured by SWE, showed huge overlap between malignant and benign nodules, and low diagnostic accuracy in the prediction of thyroid malignancy. Our study supports that firmness of thyroid nodules, as assessed by SWE, should not be a key feature in the evaluation of such lesions.

Ultrasound elastography of the thyroid: principles and current status

Ultrasound (US) elastography has been introduced as a non-invasive technique for evaluating thyroid diseases. This paper presents a detailed description of the technical principles, peculiarities, and limitations of US elastography techniques, including strain elastography and shear-wave elastography. This review was conducted from a clinical perspective, and aimed to assess the usefulness of US elastography for thyroid diseases in specific clinical scenarios. Although its main focus is on thyroid nodules, the applications of US elastography for other thyroid diseases, such as diffuse thyroid diseases and thyroiditis, are also presented. Furthermore, unresolved questions and directions for future research are also discussed.

Three-Dimensional Shear Wave Elastography for Differentiating Benign From Malignant Thyroid Nodules

OBJECTIVES

To prospectively evaluate the diagnostic performance of 3-dimensional (3D) shear wave elastography (SWE) for assessing thyroid nodules.

METHODS

A total of 176 surgically or cytologically confirmed thyroid nodules (63 malignant and 113 benign) in 176 patients who had undergone conventional ultrasound (US), 2-dimensional (2D) SWE, and 3D SWE examinations were included in this study. Quantitative elasticity values (mean elasticity, maximum elasticity, and standard deviation of elasticity of a large region of interest and mean elasticity of a 2-mm region of interest) were measured on 2D and 3D SWE. Diagnostic performances of conventional US, 2D SWE, and 3D SWE were assessed. The role of 2D and 3D SWE in reducing unnecessary fine-needle aspiration (FNA) for nodules with low suspicion was also evaluated.

RESULTS

The diagnostic performances in terms of the area under the receiver operating characteristic curve were 0.612 for conventional US, 0.836 for 2D SWE (P < .001 in comparison with conventional US), and 0.839 for 3D SWE (P < .001 in comparison with conventional US). The mean elasticity achieved the highest diagnostic performance in 2D SWE, whereas the standard deviation of elasticity achieved the highest performance in 3D SWE, although no significant difference was found between them (P > .05). Three-dimensional SWE increased the specificity in comparison with 2D SWE (88.5% versus 82.3%; P = .039). For the 37 nodules with low suspicion on conventional US imaging, 2D SWE was able to avoid unnecessary FNA in 77.1% (27 of 35) of benign nodules, and 3D SWE further increased the number to 88.6% (31 of 35).

CONCLUSIONS

Three-dimensional SWE is a useful tool for predicting thyroid nodule malignancy and reducing unnecessary FNA procedures in thyroid nodules with low suspicion of malignancy.

Association between BRAF V600E Mutation and Ultrasound Features in Papillary Thyroid Carcinoma Patients with and without Hashimoto's Thyroiditis

To assess the association between BRAF V600E mutation and ultrasound (US) features in papillary thyroid carcinoma (PTC) patients with and without Hashimoto’s thyroiditis (HT). We retrospectively reviewed the US features and status of BRAF V600E mutation in 438 consecutive patients with surgically confirmed PTCs. The association between BRAF mutation and US features were analyzed. In addition, we conducted subgroup analyses in terms of coexistent HT. The BRAF mutation was found in 86.5% of patients (379 of 438). Patient age (OR: 1.028, P = 0.010), age ≥ 50 y (OR: 1.904, P = 0.030), and microcalcification (OR: 2.262, P = 0.015) on US were significantly associated with BRAF mutation in PTC patients. Solid component (OR: 5.739, P = 0.019) on US was the significant predictor for BRAF mutation in patients with HT, while age (OR: 1.036, P = 0.017) and microcalcification (OR: 3.093, P = 0.017) were significantly associated with BRAF mutation in patients without HT. In conclusion, older age and microcalcification are risk factors for BRAF mutation in PTC patients, especially in those without HT. For those with HT, however, PTCs with BRAF mutation tend to be solid on ultrasound. These factors might be considered when making treatment planning or prognosis evaluation.