Virtual touch tissue imaging and quantification (VTIQ) in the evaluation of thyroid nodules: the associated factors leading to misdiagnosis

Comparing shear wave elastography of breast tumors and axillary nodes in the axillary assessment after neoadjuvant chemotherapy in patients with node-positive breast cancer

BACKGROUND

Accurately identifying patients with axillary pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) in breast cancer patients remains challenging.

PURPOSE

To compare the feasibility of shear wave elastography (SWE) performed on breast tumors and axillary lymph nodes (LNs) in predicting the axillary status after NAC.

MATERIALS AND METHODS

This prospective study included a total of 319 breast cancer patients with biopsy-proven positive node who received NAC followed by axillary lymph node dissection from 2019 to 2022. The correlations between shear wave velocity (SWV) and pathologic characteristics were analyzed separately for both breast tumors and LNs after NAC. We compared the performance of SWV between breast tumors and LNs in predicting the axillary status after NAC. Additionally, we evaluated the performance of the most significantly correlated pathologic characteristic in breast tumors and LNs to investigate the pathologic evidence supporting the use of breast or axilla SWE.

RESULTS

Axillary pCR was achieved in 51.41% of patients with node-positive breast cancer. In breast tumors, there is a stronger correlation between SWV and collagen volume fraction (CVF) (r = 0.52, p < 0.001) compared to tumor cell density (TCD) (r = 0.37, p < 0.001). In axillary LNs, SWV was weakly correlated with CVF (r = 0.31, p = 0.177) and TCD (r = 0.29, p = 0.213). No significant correlation was found between SWV and necrosis proportion in breast tumors or axillary LNs. The predictive performances of both SWV and CVF for axillary pCR were found to be superior in breast tumors (AUC = 0.87 and 0.85, respectively) compared to axillary LNs (AUC = 0.70 and 0.74, respectively).

CONCLUSION

SWE has the ability to characterize the extracellular matrix, and serves as a promising modality for evaluating axillary LNs after NAC. Notably, breast SWE outperform axilla SWE in determining the axillary status in breast cancer patients after NAC.

Value of conventional ultrasound and shear‑wave elastography in the assessment of mesenteric lymphadenitis in a paediatric population

The present retrospective study was designed to explore the value of conventional ultrasound (US) and Virtual Touch Tissue Imaging and Quantification (VTIQ) in the assessment of mesenteric lymphadenitis (ML) in a paediatric population. A total of 103 patients with ML and 60 healthy paediatric patients were examined. VTIQ was performed to assess mesenteric lymph node (MLN) stiffness via shear-wave velocity (SWV). Univariate and multivariate logistic regression analyses were conducted to reveal independent variables for the identification of ML. The diagnostic performance of US, and US combined with VTIQ, were compared. All the quantitative VTIQ parameters (including the SWVMean, SWVMax and SWVMin) were significantly greater for MLNs in the control group than for MLNs in the ML group (all P<0.001). The SWV values in the control group were nearly 2-fold greater than that in the ML group. According to the multivariate logistic regression analysis, the longest diameter [odds ratio (OR)=6.042; P=0.046] was revealed to be the strongest independent predictor for ML, followed by the CRP level (OR=2.310; P<0.001) and the SWVMean (OR=0.106; P<0.001). According to the receiver operating characteristic analysis, the area under the curve (AUC) for US combined with VTIQ was 0.890 (95% CI: 0.831-0.949) with a greater sensitivity of 91.26% and a greater specificity of 86.67% than that for US alone (AUC: 0.798; 95% CI: 0.724-0.872; sensitivity: 79.61%; specificity: 80.00%). A significant negative correlation between increased VTIQ parameters and ML was observed. Utilizing VTIQ to assess MLN stiffness offers a non-invasive, convenient, reliable and reproducible approach for identifying mesenteric lymphadenopathy.

Association between diagnostic efficacy of acoustic radiation force impulse for benign and malignant thyroid nodules and the presence or absence of non-papillary thyroid cancer: A meta-analysis

Purpose

The aim of this study was to investigate the diagnostic efficacy of Acoustic Radiation Force Impulse (ARFI) for benign and malignant thyroid nodules in the presence and absence of non-papillary thyroid cancer (NPTC) and to determine the cut-off values of Shear Wave Velocity (SWV) for the highest diagnostic efficacy of Virtual Touch Quantification (VTQ) and Virtual Touch Tissue Imaging and Quantification (VTIQ).

Methods

The diagnostic accuracy of ARFI for benign and malignant thyroid nodules was assessed by pooling sensitivity, specificity and area under the curve (AUC) in each group in the presence and absence of both non-papillary thyroid glands, using histology and cytology as the gold standard. All included studies were divided into two groups according to VTQ and VTIQ, and each group was ranked according to the magnitude of the SWV cutoff value to determine the SWV cutoff interval with the highest diagnostic efficacy for VTQ and VTIQ.

Results

A total of 57 studies were collected on the evaluation of ARFI for the diagnosis of benign and malignant thyroid nodules. The results showed that the presence of non-papillary thyroid carcinoma led to differences in the specificity of VTIQ for the identification of benign and malignant thyroid nodules, and the differences were statistically significant. In addition, the diagnostic efficacy of VTQ was best when the cutoff value of SWV was in the interval of 2.48-2.55 m/s, and the diagnostic efficacy of VTIQ was best when the cutoff value of SWV was in the interval of 3.01-3.15 m/s.

Conclusion

VTQ and VTIQ have a high diagnostic value for benign and malignant thyroid nodules; however, when the malignant nodules in the study contain non-papillary thyroid carcinoma occupying the thyroid gland, the findings should be viewed in a comprehensive manner.

The impact of the ultrasound classification on the rate of thyroid surgery indications: a 577 cases series

OBJECTIVES

Nodules of the thyroid gland are common but rarely malignant. Their management can range from simple monitoring to surgery. The use of ultrasound and fine needle aspiration can reduce the rate of unnecessary surgeries. However, there is a risk of false positives and false negatives of malignancy that only pathology can avoid. The objective of this study is to assess the impact of ultrasound classification on the rate of surgical indications.

MATERIAL AND METHODS

Between 2013 and 2017, the ultrasound classification was gradually adopted in our daily practice to become now routine. During this period, we conducted a retrospective study of all the patients who presented to our department for one or more thyroid nodules.

RESULTS

A total of 577 patients were included in the study. We compared two groups, a first where the ultrasound classification was used and a second where this classification was not used. In the end, we found that this classification significantly reduced the surgical indication by 19% while increasing the malignancy detection rate in operated patients by 21%.

CONCLUSIONS

The use of ultrasound classification reduces the indications for surgery while increasing the rate of malignancy in operated patients. The generalization of the use of the ultrasound classification score is strongly recommended in daily practice.

Added value of mass characteristic frequency to 2-D shear wave elastography for differentiation of benign and malignant thyroid nodules

Mass characteristic frequency (f_mass) is a novel shear wave (SW) parameter that represents the ratio of the averaged minimum SW speed within the regions of interest to the largest dimension of the mass. Our study objective was to evaluate if the addition of f_mass to conventional 2-D shear wave elastography (SWE) parameters would improve the differentiation of benign from malignant thyroid nodules. Our cohort comprised 107 patients with 113 thyroid nodules, of which 67 (59%) were malignant. Two-dimensional SWE data were obtained using the Supersonic Imagine Aixplorer ultrasound system equipped with a 44- to 15-MHz15-MHz linear array transducer. A receiver operating characteristic curve was generated based on a multivariable logistic regression analysis to evaluate the ability of SWE parameters with/without f_mass and with/without clinical factors to discriminate benign from malignant thyroid nodules. The addition of f_mass to conventional SW elasticity parameters increased the area under the curve from 0.808 to 0.871 (p = 0.02). The combination of SW elasticity parameters plus f_mass plus clinical factors provided the strongest thyroid nodule malignancy probability estimate, with a sensitivity of 93.4% and specificity of 91.1% at the optimal threshold. In summary, f_mass can be a valuable addition to conventional 2-D SWE parameters.

Combining conventional ultrasound and sonoelastography to predict axillary status after neoadjuvant chemotherapy for breast cancer

OBJECTIVE

To determine the ability of conventional ultrasound (US) combined with shear wave elastography (SWE) to reveal axillary status after neoadjuvant chemotherapy (NAC) in breast cancer patients.

METHODS

From September 2016 to December 2021, 201 patients with node-positive breast cancer who underwent NAC were enrolled in this prospective study. Conventional US features of axillary lymph nodes and SWE characteristics of breast lesions after NAC were analyzed. The diagnostic performances of US, SWE, and their combination were assessed using multivariate logistic regression and receiver operator characteristic curve (ROC) analyses.

RESULTS

The area under the ROC curve (AUC) for the ability of conventional US features to determine axillary status after NAC was 0.82, with a sensitivity of 85.23%, a specificity of 67.39%, and an accuracy of 76.11%. Shear wave velocity (SWV) displayed moderate performance for predicting axilla status after NAC with SWV_mean demonstrating an AUC of 0.85. Cortical thickness and shape of axillary nodes and SWV_mean of breast tumors were independently associated with axillary nodal metastasis after NAC. Compared to conventional US, the combination of conventional US of axillary lymph nodes with SWE of breast lesions achieved a significantly higher AUC (0.90 vs 0.82, p < 0.01, Delong's test) with a sensitivity of 87.50%, improved specificity of 82.61% and accuracy of 85.00%.

CONCLUSIONS

Breast SWE was independently associated with residual metastasis of axillary node after NAC in patients with initially diagnosed positive axilla. Combining SWE with conventional US showed good diagnostic performance for axillary node disease after NAC.

KEY POINTS

• Breast SWE can serve as a supplement to axilla US for the evaluation of the axilla after NAC. • The combination of axilla US with breast SWE may be a promising method to facilitate less-invasive treatment in patients receiving NAC.

Evaluation of Ultrasound Elastography Combined With Chi-Square Automatic Interactive Detector in Reducing Unnecessary Fine-Needle Aspiration on TIRADS 4 Thyroid Nodules

Background

Conventional ultrasound diagnosis of thyroid nodules (TNs) had a high false-positive rate, resulting in many unnecessary fine-needle aspirations (FNAs).

Objective

This study aimed to establish a simple algorithm to reduce unnecessary FNA on TIRADS 4 TNs using different quantitative parameters of ultrasonic elasticity and chi-square automatic interactive detector (CHAID) method.

Methods

From January 2020 to May 2021, 432 TNs were included in the study, which were confirmed by FNA or surgical pathology. Each TN was examined using conventional ultrasound, sound touch elastography, and Shell measurement function. The quantitative parameters E and E_shell were recorded, and the E_shell/E values were calculated for each TN. The diagnostic performance of the quantitative parameters was evaluated using the receiver operating characteristic curves. The CHAID was used to classify and analyze the quantitative parameters, and the prediction model was established.

Results

A total of 226 TNs were malignant and 206 were benign. E_shell and E_shell/E ratio were included in the classification algorithm, which showed a depth of two ramifications (E_shell/E ≤ 0.988 or 0.988–1.043 or >1.043; if E_shell/E ≤ 0.988, then E_shell ≤ 64.0 or 64.0–74.0 or >74.0; if E_shell/E = 0.988–1.043, then E_shell ≤ 66.0 or > 66.0; if E_shell/E >1.043, then E_shell ≤ 69.0 or >69.0). The unnecessary FNAs could have been avoided in 57.3% of the cases using this algorithm.

Conclusion

The prediction model using quantitative parameters had high diagnostic performance; it could quickly distinguish benign lesions and avoid subjective influence to some extent.

Preoperative Evaluation of Central Lymph Nodes in Papillary Thyroid Carcinoma Using High-Resolution Ultrasound and Shear-Wave Elastography

ABSTRACT

The aim of this study was to discuss the diagnostic value of high-resolution ultrasound and virtual touch tissue imaging quantification (VTIQ) for distinguishing metastatic and benign central lymph nodes (CLNs) in patients with papillary thyroid carcinoma. This retrospective study involved 86 pathologically proven benign lymph nodes (LNs) and 118 metastatic LNs in patients with papillary thyroid carcinoma. We analyzed the sonographic features of CLNs (size, shape, distribution, hilum, echogenicity, cystic change, calcification, vascularity, shear-wave velocity [SWV]). The prevalence of sonographic features and the SWV was compared between metastatic and benign CLNs. The size, shape, margin, distribution, presence of hilum, echogenicity, calcification, and vascularity were significantly different between benign and metastatic CLNs (P < 0.05 for all). The mean maximum SWV for malignant CLNs was 3.139 ± 0.408 m/s, whereas that of benign CLNs was 2.418 ± 0.369 m/s (P < 0.05). The cutoff point of the SWV for differentiating benign and malignant LNs was 2.675 m/s. Logistic regression analysis showed that round or irregular shape, aggregation or fusion, calcification, and VTIQ value greater than 2.675 m/s of CLNs were independent risk factors for malignancy, with an odds ratio of 5.77, 3.05, 3.23, and 62.85, respectively. High-resolution ultrasound and VTIQ can provide valuable information for distinguishing metastatic from benign CLNs.

Strain Imaging in the Evaluation of Thyroid Nodules: The Associated Factors Leading to Misdiagnosis

This study analyzed which imaging characteristics may contribute to misdiagnosis of benign and malignant thyroid nodules (TNs) through strain imaging (SI). We analyzed SI parameters and conventional ultrasound (CUS) characteristics of 264 nodules with histopathology results and we applied binary logistic regression analysis to select independent variables for incorrect SI results. The elastography imaging (EI) score and the virtual touch tissue imaging (VTI) score of malignant TNs were remarkably higher than that in benign TNs. VTI, of which the false-positive rate (FPR), the false-negative rate (FNR), and the cutoff value were 47.6% (39/82), 17.6% (32/182) and 3.5, presented higher diagnostic performance than EI. Aspect ratio (odd ratio [OR]: 14.208) and intra-nodular calcification (OR: 20.384) were significantly associated with false-positive VTI findings, while posterior acoustic feature (OR: 30.424) was significantly associated with false-negative VTI findings. Sex (OR: 0.221) and aspect ratio (OR: 0.268) were negatively associated with false-negative EI findings. In conclusion, sex and aspect ratio significantly affect the accuracy of EI results, while aspect ratio, intra-nodular calcification and posterior acoustic features notably affect the accuracy of VTI results. These CUS features of TNs should not be ignored before explaining SI examination results.

Added Value of Superb Microvascular Imaging and Virtual Touch Imaging Quantification in Assisting Thyroid Cancer Classification

This prospective study determined the value added by superb microvascular imaging (SMI) and Virtual Touch imaging quantification (VTIQ) to conventional ultrasonography in classifying malignant and benign thyroid nodules. One hundred eighty-three thyroid nodules (TNs) in 120 patients (112 benign and 71 malignant TNs) were evaluated. SMI revealed noticeable variance between benign and malignant TNs (p < 0.001). Malignant nodules tended to have rich vascularity (grade 3: 38/71, 53.5%) compared with benign nodules (grade 3: 33/112, 29.5%). There is a statistically significant difference between malignant and benign TNs with respect to shear-wave speed (SWS) values (all p values <0.001). The SWS mean, maximum and ratio of malignant nodules were 3.97 ± 1.34, 4.79 ± 1.70 and 1.25 ± 0.39, respectively. The SWS mean, maximum and ratio of benign nodules were 2.65 ± 0.42, 2.97 ± 0.46 and 1.15 ± 0.35, respectively. With respect to area under the curve values, the combined use of SMI or VTIQ improved the diagnostic performance of classifying malignant and benign TNs compared with that of ultrasonography alone. The combination of three modalities achieved the greatest area under the curve values (0.9811, 95% confidence interval: 0.95529-1.000), followed by US + VTIQ (0.9747, 0.94543-1.000), US + SMI (0.9032, 0.85345-0.95391) and ultrasonography (0.8291, 0.76417-0.89403).

Applications of Mechanical Arm in the Virtual Touch Tissue Imaging Quantification and the Differential Diagnosis of Breast Tumors

ABSTRACT

To assess the diagnostic performance of quantitative parameters for virtual touch tissue imaging quantification by the mechanical arm probe, 128 women with 152 breast lesions (90 benign and 62 malignant) were included and maximum elasticity (Vmax), median elasticity (Vmean), maximum elasticity minus minimum (Vmax-min), and minimum elasticity (Vmin) were measured. Intercorrelation coefficients and Bland-Altman plots were used to compare the repeatability and consistency of handheld probe and mechanical arm measurements. Receiver operating characteristic curve was used to evaluate the diagnostic efficiency. The results showed that intercorrelation coefficients were 0.694 to 0.951 by the mechanical arm and 95% limits of agreement were wider than handheld probe. Using 4.36 m/s as cutoff value for Vmax by the mechanical arm, we achieved sensitivity (88.7%) and specificity (90.0%). We concluded that the mechanical arm can reduce the influence of different scanning pressures on the elastic modulus of breast tissue.

The Value of Ultrasound-Guided Fine-Needle Aspiration Cytology Combined with Puncture Feeling in the Diagnosis of Thyroid Nodules

INTRODUCTION

There are few studies on the role of puncture feeling in thyroid nodules during ultrasound-guided fine-needle aspiration cytology (US-FNAC), although it is expected to become a new predictive technique. We aimed to analyze the importance of puncture feeling in combination with US-FNAC and investigate whether it can be used as an indicator to predict the nature of thyroid nodules.

MATERIALS AND METHODS

From January 1, 2018, to October 31, 2020, a total of 623 thyroid nodules were included. Puncture feeling was classified as "soft," "hard," or "hard with grittiness." The correlation between puncture feeling and postoperative pathology and the diagnostic value of FNAC combined with puncture feeling were analyzed, and the influence of thyroid nodule size on puncture feeling, FNAC, and FNAC combined with puncture feeling was studied. We further explored the correlation between puncture feeling and histopathology in Bethesda III and IV thyroid nodules.

RESULTS

There was a significant correlation between puncture feeling and postoperative pathology (p < 0.001). The sensitivity, negative predictive value, and total coincidence rate of US-FNAC combined with puncture feeling for the diagnosis of thyroid nodules were higher than those of US-FNAC alone (96.1, 83.6, and 94.7% vs. 89.0, 65.5, and 89.7%, respectively). Thyroid nodule size was the influencing factor for puncture feeling, FNAC, and FNAC combined with puncture feeling (p < 0.05 for all). The area under the curve for puncture feeling, FNAC, and FNAC combined with puncture feeling for thyroid nodules of size ≤1 cm was greater than for modules of size >1 cm. Puncture feeling was of great value in diagnosing Bethesda III thyroid nodules (p < 0.001), and all Bethesda IV thyroid nodules had puncture feeling of soft.

CONCLUSION

Puncture feeling is of great value during US-FNAC. "Hard" and "hard with grittiness" were indicators for malignancy, while "soft" indicated that the thyroid nodule was likely to be benign. The diagnostic value of US-FNAC combined with puncture feeling for thyroid nodules is higher than US-FNAC alone, especially when nodule size is ≤1 cm. Puncture feeling is of great value in predicting the nature of Bethesda III thyroid nodules.

Assessment of perinodular stiffness in differentiating malignant from benign thyroid nodules

OBJECTIVE

We evaluated the diagnostic accuracy of perinodular stiffness, four risk stratification systems (RSSs) (KWAK-TIRADS, ACR-TIRADS, EU-TIRADS, and C-TIRADS), and the combination of perinodular stiffness and the four RSSs in differentiating malignant from benign thyroid nodules (TNs).

METHODS

A total of 788 TNs in 726 patients were examined with conventional ultrasound (US) examination and sound touch elastography (STE). All TNs were classified by each of the four RSSs. The stiffness inside (E) the TNs was measured by STE. The stiffness of the 2.0-mm perinodular region (Eshell) was measured with the Shell measurement function of STE. The diagnostic performances of four RSSs, the E values, and the Eshell values were evaluated. All TNs were further divided into subgroups based on size (≤ 10 mm group and > 10 mm group).

RESULTS

Ninety-six TNs were classified as benign and 692 as malignant. Among the single-method approaches, ACR-TIRADS showed the highest AUC (0.77) for differentiating malignant from benign TNs for all TNs included. Eshell showed the highest AUC (0.75) in differentiating malignant from benign TNs for TNs with sizes ≤ 10 mm, and there were no significant differences in AUC among all single methods for diagnosis of TNs with sizes > 10 mm (P > 0.05). The combination of C-TIRADS and Eshell/E yielded the highest AUC for all TNs (0.83) and for TNs with size ≤ 10 mm (0.85) compared with other combinations.

CONCLUSIONS

Eshell/E combined with conventional US improves the diagnostic accuracy in TNs and may reduce unnecessary fine-needle aspiration.

Reducing Unnecessary Biopsy of American College of Radiology Thyroid Imaging Reporting and Data System Category 4 Nodules

OBJECTIVES

To assess the effectiveness of strain elastography (SE), Virtual Touch tissue imaging and quantification (VTIQ; Siemens Medical Solutions, Mountain View, CA) and their combination (SE + VTIQ) in distinguishing benign from malignant American College of Radiology Thyroid Imaging Reporting and Data System category 4 nodules (TR4) to reduce unnecessary biopsy.

METHODS

In this retrospective study, 985 thyroid nodules from 920 patients were initially enrolled and examined with conventional ultrasound, SE, and VTIQ. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of SE, VTIQ, and SE + VTIQ were calculated respectively. An area under the receiver operating characteristic curve analysis was applied to evaluate the diagnostic efficiency of SE, VTIQ, and SE + VTIQ in the differentiation of benign and malignant TR4 nodules.

RESULTS

A total of 864 patients with 922 TR4 nodules were enrolled ultimately, as 63 thyroid nodules from 56 patients were excluded because they did not meet the inclusion criteria of this study. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of SE, VTIQ, and SE + VTIQ were 72.4% versus 86.3% versus 82.1%, 77.7% versus 80.5% versus 83.5%, 70.6% versus 76.1% versus 80.2%, 73.4% versus 76.3% versus 83.5%, and 75.5% versus 79.7% versus 82.8%, respectively. The areas under the receiver operating characteristic curve for the diagnosis of TR4 nodules by SE, VTIQ, and SE + VTIQ were 0.751, 0.817, and 0.844.

CONCLUSIONS

In spite of a slight decrease in the sensitivity, the application of combining SE and VTIQ techniques can improve the specificity and accuracy of TR4 nodule diagnosis, which can help reduce unnecessary biopsies of TR4 nodules.

Value of Contrast-Enhanced Ultrasound in Partially Cystic Papillary Thyroid Carcinomas

Partially cystic papillary thyroid carcinomas (PCPTCs) are rarely reported papillary thyroid carcinomas (PTCs) and are usually misdiagnosed as benign nodules. The objective of this study was to provide the various sonographic characteristics of partially cystic thyroid nodules for differentiation between malignant and benign nodules, including those for conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS). Twenty-three PCPTC patients and 37 nodular goiter patients were enrolled in this study. We evaluated the size, cystic percentage, solid echogenicity, calcification, vascularity, and CEUS parameters for each nodule. The final diagnosis of all patients was confirmed via surgery. Univariate analysis demonstrated that compared with benign nodular goiters, PCPTCs more frequently presented with calcification, hypoechogenicity of the solid part, hypoenhancement, heterogeneous enhancement, centrifugal perfusion, peak intensity index <1, time to peak index ≥1, and area under the curve index <1 on preoperative US and CEUS. Binary logistic regression analysis demonstrated that heterogeneous enhancement, centrifugal perfusion, and peak intensity index <1 are independent CEUS characteristics related to malignant PCPTCs and can be used for their differentiation from benign nodular goiters (all p < 0.05). Our study indicated that preoperative CEUS characteristics may serve as a useful tool to distinguish malignant PCPTCs from benign thyroid nodules.

Virtual touch imaging quantification shear-wave elastography for breast lesions: the diagnostic value of qualitative and quantitative features

AIM

To investigate the value of the qualitative and quantitative features of Virtual Touch imaging quantification (VTIQ) shear-wave elastography in the characterisation of breast lesions.

MATERIALS AND METHODS

Conventional ultrasound (US) and VTIQ were performed in 148 solid breast lesions in 148 women. During qualitative analysis, patterns of VTIQ were categorised into two patterns, 1 and 2. During quantitative analysis, the mean SWV (SWVmean) and the maximum SWV (SWVmax) of each lesion were used. The sensitivity, specificity, and the areas under the receiver operating characteristic (ROC) curve (Az value) were calculated for conventional US, VTIQ, and combined conventional US and VTIQ.

RESULTS

Malignant lesions were more likely to show VTIQ pattern 2 than the benign lesions (p<0.001). There was no significant difference in the Az values between SWVmean (0.907) and SWVmax (0.902; p=0.572). There was no significant difference in the Az values between the VTIQ pattern (0.884) and SWVmax (p=0.572). The combined conventional US and VTIQ pattern carried a similar Az value (0.949) as compared with the combined conventional US and SWVmax, which yielded an Az value of 0.952 (p=0.683).

CONCLUSION

The combination of either VTIQ pattern or SWVmax and conventional US may be helpful in the characterisation of benign and malignant breast lesions.

Evaluation of the Perinodular Stiffness Potentially Predicts the Malignancy of Thyroid Nodules

OBJECTIVES

To evaluate the surrounding tissue stiffness measured by sound touch elastography for differential diagnosis of thyroid nodules (TNs).

METHODS

Thirty-nine benign and 90 malignant TNs were included in this study. The conventional ultrasound features, the maximum Young modulus value of the stiffness of the TNs (recorded as E), and the stiffness of the 0.5-, 1.0-, 1.5-, and 2.0-mm perinodular regions of the TNs (recorded as E_shell0.5 , E_shell1.0 , E_shell1.5 , and E_shell2.0 , respectively) were prospectively analyzed and compared to histopathologic results. The abundance of collagen fibers at various widths in the perinodular regions of the TNs was evaluated by Masson staining and ImageJ software (National Institutes of Health, Bethesda, MD). The fibrous structures in the perinodular regions of the TNs were classified.

RESULTS

The various E_shell values of malignant TNs were significantly higher than those of benign TNs (P < .001 for all). E_shell0.5 correlated highly with E in the malignant TNs and in all samples (r = 0.722 and 0.772; P < .001 for both). _Eshell2 yielded the highest area under the receiving operating characteristic curve value (0.96) for the differential diagnosis of TNs. The abundance of collagen fibers in the 2-mm perinodular region of the TNs was closely correlated with E_shell2 in the malignant TNs and in all samples (r =0.729 and 0.867; P < .001). The E_shell2 values for different levels of disorder of the tissue surrounding TNs were significantly different (P < .01 for all).

CONCLUSIONS

Perinodular stiffness measured by sound touch elastography improved the diagnostic accuracy in TNs.

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.

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.

Sonographic Characteristics of Papillary Thyroid Carcinoma with Coexistent Hashimoto's Thyroiditis: Conventional Ultrasound, Acoustic Radiation Force Impulse Imaging and Contrast-Enhanced Ultrasound

Our objective was to provide the various sonographic characteristics of papillary thyroid carcinomas for Hashimoto's thyroiditis (HT) patients, including conventional ultrasound (US), acoustic radiation force impulse Virtual Touch imaging and quantification (ARFI-VTIQ) and contrast-enhanced ultrasound (CEUS). Sixty-nine HT patients with 85 thyroid nodules (TNs) (49 malignant and 36 benign) were enrolled in this study. We evaluated the size, shape, margin, echogenicity, presence of halo, calcification, vascularity and ARFI-VTIQ and CEUS parameters for each nodule and compared the findings with the reference standards of histopathological and/or cytologic results. Univariate analysis indicated that compared with benign TNs with HT, papillary thyroid carcinomas with HT more often had taller-than-wider shapes, ill-defined margins, microcalcifications, peripheral vascularity, relatively harder stiffness with a higher shear wave speed, hypo-enhancement, peak intensity index <1 and area under the curve index <1 at pre-operative US, ARFI-VTIQ and CEUS. Multivariate analysis revealed that ill-defined margins, microcalcifications and peak intensity index <1 are independent characteristics related to malignant TNs for their differentiation from benign TNs (all p < 0.05). Our study indicated that pre-operative multiparameter US characteristics may serve as a useful tool to identify malignant TNs in HT patients.

Nodular Thyroid Disease in the Era of Precision Medicine

Management of thyroid nodules in the era of precision medicine is continuously changing. Neck ultrasound plays a pivotal role in the diagnosis and several ultrasound stratification systems have been proposed in order to predict malignancy and help clinicians in therapeutic and follow-up decision. Ultrasound elastosonography is another powerful diagnostic technique and can be an added value to stratify the risk of malignancy of thyroid nodules. Moreover, the development of new techniques in the era of "Deep Learning," has led to a creation of machine-learning algorithms based on ultrasound examinations that showed similar accuracy to that obtained by expert radiologists. Despite new technologies in thyroid imaging, diagnostic surgery in 50-70% of patients with indeterminate cytology is still performed. Molecular tests can increase accuracy in diagnosis when performed on "indeterminate" nodules. However, the more updated tools that can be used to this purpose in order to "rule out" (Afirma GSC) or "rule in" (Thyroseq v3) malignancy, have a main limitation: the high costs. In the last years various image-guided procedures have been proposed as alternative and less invasive approaches to surgery for symptomatic thyroid nodules. These minimally invasive techniques (laser and radio-frequency ablation, high intensity focused ultrasound and percutaneous microwave ablation) results in nodule shrinkage and improvement of local symptoms, with a lower risk of complications and minor costs compared to surgery. Finally, ultrasound-guided ablation therapy was introduced with promising results as a feasible treatment for low-risk papillary thyroid microcarcinoma or cervical lymph node metastases.

Pre-operative Conventional Ultrasound and Sonoelastography Evaluation for Predicting Axillary Lymph Node Metastasis in Patients with Malignant Breast Lesions

The objective of our study was to evaluate the association between the sonoelastography features of breast tumor and axillary lymph node metastasis (ALNM) in patients with breast cancer. In a cohort of 106 women with breast cancer, the conventional ultrasound features and elasticity parameters by elasticity imaging and Virtual Touch Tissue Imaging & Quantification (VTIQ) were retrospectively analyzed. Ultrasound and elastography findings were compared with pathologic axillary lymph node status. Receiver operating characteristic curve analysis was used to evaluate diagnostic performance. Pathologically, the overall incidence of ALNM was 39.6% (42/106) in the final analysis. ALNM was significantly more frequent in tumors with elasticity imaging scores >4.5, maximal shear wave velocity values (Smax) >6.42 m/s and mean shear wave velocity values (Smean) >5.66 m/s, respectively. The sensitivity, specificity and accuracy were 78.6%, 54.7% and 64.2% for elasticity imaging score; 85.7%, 54.7% and 67.0% for Smax; and 59.5%, 79.7% and 71.7% for Smean, respectively Elastography features, including elasticity imaging score and VTIQ, can be used to supplement conventional ultrasound to predict ALNM in patients with breast cancers.

Evaluation of the Stiffness of Tissues Surrounding Thyroid Nodules with Shear Wave Elastography

OBJECTIVES

This study evaluated the stiffness of tissue surrounding thyroid nodules using shear wave elastography (SWE).

METHODS

A total of 128 thyroid nodules in 108 patients were examined with conventional ultrasound imaging and SWE. The maximum Young modulus value was measured to evaluate the stiffness of the thyroid nodules (E) and the 2-mm perinodular region (E_shell ). The number of thyroid fibrocytes was evaluated by Masson trichrome staining and image-processing software. The arrangement of the fibrous structure was also classified.

RESULTS

The mean age ± SD of the 108 patients was 33.12 ± 13.34 years (range, 18-80 years). Thirty-nine thyroid nodules were classified as benign and 89 as malignant. E_shell was significantly higher for malignant nodules (95.0 ± 21.9 kPa) compared with benign nodules (48.1 ± 17.0 kPa; P < .001). E_shell yielded an area under the receiver operator characteristic curve value of 0.951, which was used for the diagnosis of nodules. There was a high positive correlation between E and E_shell in the malignant group (R = 0.722; P < .001) and a moderate positive correlation in the benign group (R = 0.601; P < .001). Percentages of fibrocytes correlated highly with E_shell in all samples as well as in malignant samples (R = 0.867 and R = 0.729, respectively; P < .001). The degree of disorder of the tissue surrounding thyroid nodules was positively correlated with E_shell (R = 0.833).

CONCLUSIONS

Perinodular stiffness has potential to improve diagnosis of thyroid nodules.

VTIQ evaluates antitumor effects of NET-1 siRNA by UTMD in HCC xenograft models

The present study used a virtual touch tissue imaging and quantification (VTIQ) method to investigate the change in elasticity in xenograft tumor tissue models following silencing of the neuroepithelial-transforming protein 1 (NET-1) gene by ultrasound-targeted microbubble destruction (UTMD). A total of 24 xenograft models were established by subcutaneous injection of human hepatocellular carcinoma SMMC-7721 cells in BALB/c female nude mice. Then, NET-1 small interfering RNA (siRNA)-conjugated nanobubbles and a glypican-3 antibody were synthesized. The mean and maximum shear wave speed (SWS_mean and SWS_max) in the tumor tissue were measured prior to, during, and following therapy using VTIQ. The growth of the tumor size and survival time were recorded. The levels of NET-1 protein were evaluated by immunohistochemical staining. In addition, tumor, liver and kidney tissues of the nude mice were collected to confirm whether gene transfection treatment was toxic in vivo. In the UTMD delivery gene group, SWS_mean was correlated with the maximum diameter of the tumor (r=0.9806, P=0.0194). The immunohistochemical staining data indicated that the level of NET-1 protein in the treated groups was significantly decreased compared with those in the control groups. Additionally, no structural damage was observed in the nude mice liver and kidney tissues following treatment. Therefore, VTIQ measurement identified potential changes in the elastic properties of the tumors, which in turn may be associated with the stages of tumor development. The delivery method, UTMD, improves the antitumor effects of NET-1 siRNA and supports gene transfection as a promising therapeutic strategy.

Use of the Kwak Thyroid Image Reporting and Data System (K-TIRADS) in differential diagnosis of thyroid nodules: systematic review and meta-analysis

PURPOSE

The purpose of this systematic literature review was to assess the usefulness of the Thyroid Image Reporting and Data System (K-TIRADS) classification proposed by Kwak for differentiation of thyroid nodules.

MATERIAL AND METHODS

Four literature databases were searched for relevant articles through early January 2017. A meta-analysis was performed to calculate pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-) and diagnostic odds ratio (DOR). The area under the curve (AUC) from the pooled receiver operating characteristic (ROC) was used to assess the usefulness of this classification for differentiation of thyroid nodules. Meta-analysis was conducted by using meta-analysis software.

RESULTS

We analysed six publications describing 10,926 nodules. Pooled sensitivity, specificity, LR+, LR-, DOR, and AUC for pooled ROC were 0.983 (95 % CI 0.976-0.989), 0.552 (95 % CI 0.542-0.562), 2.666 (95 % CI 1.692-4.198), 0.05 (95 % CI 0.035-0.072), 51.020 (95 % CI 15.241-170.79) and 0.938, respectively.

CONCLUSIONS

Kwak TIRADS has high sensitivity and low specificity. Thus, it is very useful to discard the benign cases and to reduce the number of biopsies.

KEY POINTS

• Routine, adequate standardization of thyroid nodules ultrasound classification is mandatory. • Kwak TIRADS parameters are accurate for differentiating focal thyroid lesions. • Kwak TIRADS system is simple to apply. • Kwak TIRADS system may become a useful diagnostic tool.