Shear Wave Elastography Elasticity Research Articles

Can 3D Multiparametric Ultrasound Imaging Predict Prostate Biopsy Outcome?

To assess the value of 3D multiparametric ultrasound imaging, combining hemodynamic and tissue stiffness quantifications by machine learning, for the prediction of prostate biopsy outcomes. After signing informed consent, 54 biopsy-naïve patients underwent a 3D dynamic contrast-enhanced ultrasound (DCE-US) recording, a multi-plane 2D shear-wave elastography (SWE) scan with manual sweeping from base to apex of the prostate, and received 12-core systematic biopsies (SBx). 3D maps of 18 hemodynamic parameters were extracted from the 3D DCE-US quantification and a 3D SWE elasticity map was reconstructed based on the multi-plane 2D SWE acquisitions. Subsequently, all the 3D maps were segmented and subdivided into 12 regions corresponding to the SBx locations. Per region, the set of 19 computed parameters was further extended by derivation of eight radiomic features per parameter. Based on this feature set, a multiparametric ultrasound approach was implemented using five different classifiers together with a sequential floating forward selection method and hyperparameter tuning. The classification accuracy with respect to the biopsy reference was assessed by a group-k-fold cross-validation procedure, and the performance was evaluated by the Area Under the Receiver Operating Characteristics Curve (AUC). Of the 54 patients, 20 were found with clinically significant prostate cancer (csPCa) based on SBx. The 18 hemodynamic parameters showed mean AUC values varying from 0.63 to 0.75, and SWE elasticity showed an AUC of 0.66. The multiparametric approach using radiomic features derived from hemodynamic parameters only produced an AUC of 0.81, while the combination of hemodynamic and tissue-stiffness quantifications yielded a significantly improved AUC of 0.85 for csPCa detection (p-value < 0.05) using the Gradient Boosting classifier. Our results suggest 3D multiparametric ultrasound imaging combining hemodynamic and tissue-stiffness features to represent a promising diagnostic tool for biopsy outcome prediction, aiding in csPCa localization.

Ultrasound evaluation of stiffness and vascularity of renal parenchymal damage secondary to hydronephrosis in pediatric patients using shear wave elastography and superb microvascular imaging

AbstractAimsThe purpose of this study is to assess the diagnostic value of SWE (shear wave elastography) and renal parenchymal elasticity and microvascularization with the SMI (super microvascular imaging) technique in diagnosing and predicting the progression of renal parenchymal damage in pediatric patients with hydronephrosis.Patients and MethodsA total of 45 patients were included in the prospective study. To evaluate parenchymal changes, SWE and SMI‐Vacularity Index (VI) measurements were performed in various sections of the affected and normal kidneys. The affected and control renal pelvises' anteroposterior (AP) diameters were also measured.ResultsThe average SWE values were measured as 16.62 kPa for the affected kidneys, whereas the control kidneys showed an average SWE value of 12.70 kPa, indicating a statistically significant difference (p &lt; .01). Furthermore, in the affected kidneys, the average SMI‐VI value was measured as 5.92, whereas the control kidneys exhibited a higher average SMI‐VI value of 6.64, showing a statistically significant difference (p &lt; .01). A reverse correlation was found between renal pelvis AP diameter and SMI‐VI values, while a positive correlation existed between renal pelvis AP diameter and SWE values.ConclusionsWe believe that SWE and SMI may be useful for diagnosing and predicting the progression of renal parenchymal damage in pediatric hydronephrotic patients.

Radiological Significance of Shear-Wave Elastography Technique for Evaluation of Solid Breast Masses with Histopathological Correlation

Background: Although various imaging modalities are available for evaluating suspicious breast lesions, ultrasound-based Shear-Wave Elastography (SWE) is an advanced, non-invasive technique complementary to grayscale sonography. This technique evaluates the elasticity of a specific tissue by applying sonic pressure to that tissue. Objective: The aim is to assess the role of SWE in evaluating solid breast masses in correlation to histopathological study results. Subjects and Methods: This prospective study was done in a tertiary care teaching hospital from September 2019 to August 2020. A study population of 50 women aged 18 years or above with an ultrasonographic (USG) diagnosis of solid breast masses was included. Results: A significantly higher value of SWE elasticity ratio (E-mean) was observed in malignant tumors than in benign tumors (p &lt;0.0001). The area-under-curve (AUC) for the BI-RADS 4 lesions was 0.522 (95% CI, 0.343-0.701) with an E-ratio cut-off score of 85.25, the sensitivity and specificity were 50% for diagnosing malignant tumors, whereas AUC for the HPE study was 1.000 (95% CI, 1.000-1.000) with an E-ratio cut-off score of 134.25; both the sensitivity and specificity were 100% for diagnosing malignant tumors. Conclusions: Carcinoma breast is one of the most prevalent cancers globally. The most common benign tumor of the breast is a fibroadenoma, whereas Invasive Ductal Carcinoma is the most common malignant breast mass. A well-defined SWE elasticity ratio range might help predict the aggressiveness of breast tumors. SWE's correlation with BI-RADS in suspicious lesions adds to histopathology's advantage in distinguishing malignant tumors from benign ones.

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.

Binary classification of non-specific low back pain condition based on the combination of B-mode ultrasound and shear wave elastography at multiple sites.

Introduction: Low back pain (LBP) is a prevalent and complex condition that poses significant medical, social, and economic burdens worldwide. The accurate and timely assessment and diagnosis of LBP, particularly non-specific LBP (NSLBP), are crucial to developing effective interventions and treatments for LBP patients. In this study, we aimed to investigate the potential of combining B-mode ultrasound image features with shear wave elastography (SWE) features to improve the classification of NSLBP patients. Methods: We recruited 52 subjects with NSLBP from the University of Hong Kong-Shenzhen Hospital and collected B-mode ultrasound images and SWE data from multiple sites. The Visual Analogue Scale (VAS) was used as the ground truth to classify NSLBP patients. We extracted and selected features from the data and employed a support vector machine (SVM) model to classify NSLBP patients. The performance of the SVM model was evaluated using five-fold cross-validation and the accuracy, precision, and sensitivity were calculated. Results: We obtained an optimal feature set of 48 features, among which the SWE elasticity feature had the most significant contribution to the classification task. The SVM model achieved an accuracy, precision, and sensitivity of 0.85, 0.89, and 0.86, respectively, which were higher than the previously reported values of MRI. Discussion: In this study, we aimed to investigate the potential of combining B-mode ultrasound image features with shear wave elastography (SWE) features to improve the classification of non-specific low back pain (NSLBP) patients. Our results showed that combining B-mode ultrasound image features with SWE features and employing an SVM model can improve the automatic classification of NSLBP patients. Our findings also suggest that the SWE elasticity feature is a crucial factor in classifying NSLBP patients, and the proposed method can identify the important site and position of the muscle in the NSLBP classification task.

Shear-wave elastography-based nomograms predicting 21-gene recurrence score for adjuvant chemotherapy decisions in patients with breast cancer

To develop and validate nomograms based on shear-wave elastography (SWE) combined with clinicopathologic features for predicting Oncotype DX recurrence score (RS) for use with adjuvant systemic therapy guidelines. In a retrospective study, patients with breast cancer who underwent definitive surgery of the breast between August 2011 and December 2019 were eligible for this study. Those with surgery between August 2011 and March 2019 were assigned to a development set and the rest were assigned to an independent validation set. Clinicopathologic features and SWE elasticity indices were assessed with logistic regression to develop nomograms for predicting RS≥16 and≥26. Analysis of the area under the receiver operating characteristic curve (AUROC) was used to assess the performance of the nomograms. Of a total 381 women (mean age, 51±9years), 286 (mean age, 51±9years) were in the development set and 95 (mean age, 51±9years) in the validation set. All SWE elasticity indices were independently associated with each RS cutoff (odds ratio, 1.006-1.039 for RS≥16; odds ratio, 1.008-1.076 for RS≥26). Nomograms based on SWE combined with clinicopathologic features were developed and validated for RS≥16 (mean elasticity [AUROC, 0.74; 95% CI: 0.68, 0.80] and maximum elasticity [AUROC, 0.74; 95% CI: 0.69, 0.80]) and for RS≥26 (mean elasticity [AUROC, 0.81; 95% CI: 0.73, 0.89], maximum elasticity [AUROC, 0.82; 95% CI: 0.74, 0.89], and elasticity ratio [AUROC, 0.86; 95% CI: 0.80, 0.93]). Nomograms based on SWE can predict Oncotype DX RS for use in adjuvant systemic therapy decisions.

Evaluation of renal fibrosis in patients with chronic kidney disease by shear wave elastography: a comparative analysis with pathological findings.

To explore the elastic values obtained by shear wave elastography (SWE) in assessing renal fibrosis in chronic kidney disease (CKD). One hundred and twenty-four patients with CKD who underwent renal biopsy were prospectively enrolled between April 2019 and June 2021. SWE was performed to measure the renal cortex stiffness, presented as SWE parameters, including the minimum, mean, and maximum elasticity (namely Emin, Emean, and Emax). Then, the patients with different kidney pathological impairment (mild, moderate, and severe groups) were compared in SWE elasticity and the discriminative capacity was also analyzed. For the pathology impaired grade, SWE parameter was significantly reduced in the moderately and severely impaired group than the mild one. Emax parameter achieved the best discriminative ability toward differentiating moderate-severe impairment from mild one, yielding an area under the curve (AUC) of 0.764 (95%CI: 0.681-0.848). Regarding interstitial fibrosis/tubular atrophy and global glomerular sclerosis, the Emax values were significantly reduced across the group of patients with moderate grade compared to those with mild grade. Patients in severe group were also with reduced elastic value than those in mild one, while the difference was non-significant in interstitial fibrosis/tubular atrophy but a borderline statistical significance was achieved in global glomerular sclerosis. For grade of vessel wall thickening, patients in moderate (33.04 ± 9.86kPa, P = 0.009) and severe (31.42 ± 9.16kPa, P < 0.001) group were with significantly lower elastic value compared with those in the mild one (39.58 ± 9.67kPa). The SWE parameter was linearly reduced as grade of vessel wall thickening elevated (P for trend: < 0.001). SWE derived elastic values reduced as pathology grade of renal fibrosis or grade of vessel wall thickening progresses in patients with CKD, which may be attributed to renal hypo-perfusion rather than tubulo-interstitial fibrosis progression.

Shear wave elastography for intracranial epidermoid tumors

Ultrasound elastography (USE) is a novel technique that assesses the mechanical properties of body tissues in real time. Based on elasticity measurements, USE enables the differentiation of tumor tissue from surrounding normal tissue. We aimed to evaluate an intraoperative SWE technique for differentiating tumor tissue (epidermoid cyst) from the surrounding normal brain tissue based on elastic properties. We prospectively report the intraoperative elasticity assessments of four patients diagnosed with epidermoid cysts. Along with standard ultrasonography, intraoperative shear wave elastography (SWE) was used to identify tumor tissue and assess the elasticity of each tumor and the surrounding normal brain. USE enabled the differentiation between epidermoid cysts and the surrounding normal brain tissue in real time intraoperatively; visual data (SWE elasticity map) and quantitative data (elasticity measurements in kilopascals) were utilized to identify the epidermoid cyst based on its elastic properties. The area representing the epidermoid cyst had an increased elasticity on SWE view and high mean elasticity values (193.7 ± 70.9 kPa in case 1, 168 ± 24.5 kPa in case 2, 205.1 ± 6.7 kPa in case 3, and 101.3 ± 12.6 kPa in case 4). The area representing the adjacent normal brain tissue on SWE view had lower mean elasticity values (14.9 ± 1.9 kPa in case 1, 22.6 ± 8.3 kPa in case 2, and 23.8 ± 1.4 kPa in case 4). This study demonstrates the feasibility and promising value of SWE as an intraoperative tool during epidermoid cyst resection. Epidermoid tissue remnants that are hidden from the microscopic view can be detected using SWE.

A retrospective study of reducing unnecessary thyroid biopsy for American College of Radiology Thyroid Imaging Reporting and Data Systems 4 assessment through applying shear wave elastography.

Objective The purpose of the study is to quantitatively assess shear-wave elastography (SWE) value in American College of Radiology Thyroid Imaging Reporting and Data Systems (ACR TI-RADS) 4. Materials and methods One hundred and fifty-two ACR TI-RADS 4 thyroid nodules undergoing SWE were included in the study. The mean (EMean), minimum (EMin) and maximum (EMax) of SWE elasticity were measured. Results The areas under the receiver operating characteristic (ROC) curves for SWE EMean, EMin and EMax in detecting benign and malignant nodules were 0.95, 0.83 and 0.84, respectively. Cut-off value of EMean ≤ 23.30 kPa is able to downgrade the lesion category to ACR TI-RADS 3 and cut-off value of EMean ≥ 52.14 kPa is able to upgrade the lesion category to ACR TI-RADS 5. Conclusions The EMean of SWE will probably identify nodules that have a high potential for benignity in ACR TI-RADS 4. It may help identify and select benign nodules while reducing unnecessary biopsy of benign thyroid nodules.

Diagnostic Performance of a Combination of Shear Wave Elastography and B-Mode Ultrasonography in Differentiating Benign From Malignant Thyroid Nodules.

ObjectivesThis study was conducted to compare clinicopathologic and radiologic factors between benign and malignant thyroid nodules and to evaluate the diagnostic performance of shear wave elastography (SWE) combined with B-mode ultrasonography (US) in differentiating malignant from benign thyroid nodules.MethodsThis retrospective study included 92 consecutive patients with 95 thyroid nodules examined on B-mode US and SWE before US-guided fine-needle aspiration biopsy or surgical excision. B-mode US findings (composition, echogenicity, margin, shape, and calcification) and SWE elasticity parameters (maximum [Emax], mean, minimum, and nodule-to-normal parenchymal ratio of elasticity) were reviewed and compared between benign and malignant thyroid nodules. The diagnostic performance of B-mode US and SWE for predicting malignant thyroid nodules was analyzed. The optimal cutoff values of elasticity parameters for identifying malignancy were determined. Diagnostic performance was compared between B-mode US only, SWE only, and the combination of B-mode US with SWE.ResultsOn multivariate logistic regression analysis, age (odds ratio [OR], 0.90; P=0.028), a taller-than-wide shape (OR, 11.3; P=0.040), the presence of calcifications (OR, 15.0; P=0.021), and Emax (OR, 1.22; P=0.021) were independent predictors of malignancy in thyroid nodules. The combined use of B-mode US findings and SWE yielded improvements in sensitivity, the positive predictive value, the negative predictive value, and accuracy compared with the use of B-mode US findings only, but with no statistical significance.ConclusionWhen SWE was combined with B-mode US, the diagnostic performance was better than when only B-mode US was used, although the difference was not statistically significant.

Could the “Stiff Rim Sign” Be an Indicator of Lysyl Oxidase Activity in Breast Cancer?

Background: Shear wave elastography (SWE) is a non-invasive and easily applicable imaging modality, which can provide quantitative information of tissue stiffness. Peritumoral high SWE elasticity values (stiff rim sign) has been reported in many studies. Lysyl oxidase (LOX) enzyme is implicated in the formation of peri-tumoral stiffness. Objectives: The aim of the study was to investigate the correlation between SWE measures with LOX gene expression levels in breast cancer patients. Patients and Methods: Forty seven women were included in the study. The lesions evaluated by SWE and ultrasound guided tru-cut biopsies were performed from both of the central and peripheral parts. SWE values, LOX family gene expression levels, histopathological features of the lesions, as well as axillary and distant metastasis statuses were evaluated statistically. Results: Thirty of the patients had breast cancer (BC) (the patient group) and 17 of them had fibroadenoma (the control group). Lysyl oxidase like1 (LOXL1) expression level in BC samples (central parts) were found to be significantly higher than the control group (P = 0.022). Stiff rim sign was present in all BC lesions and none of the control group. The elastography values of the patient group were significantly higher than the control group statistically (P 0.05) both for patient and control groups. Conclusion: Although there were no significant correlations between LOX expressions and SWE parameters in our study, axillary and distant metastasis were found to be correlated with SWE features, which emphasized the prognostic potential of SWE.

Does Shear Wave Elastography Score Over Strain Elastography in Breast Masses or Vice Versa?

This study was done to compare parameters of strain elastography (SE) and shear-wave elastography (SWE) for differentiation of benign and malignant breast masses and determine their best cut-offs. B mode ultrasound (USG), SE, and SWE were performed in 199 breast masses. During SE, 5-point visual elastography score (SEvisual score) and strain ratio (SEstrain ratio) were obtained. During SWE, mean and maximum elasticity values in kilopascals, and shear wave ratio were obtained in two orthogonal planes. The shear wave mean average (SWEmean avg), shear wave maximum average (SWEmax avg) and shear wave ratio average (SWEratio avg) were calculated by averaging the respective values in the two planes. The SE and SWE parameters of every mass were correlated with its histopathology. The areas under the receiver operating characteristic curve of SEvisual score, SEstrain ratio, SWEmean avg, SWEmax avg, and SWEratio avg were 0.815, 0.814, 0.846, 0.846, and 0.799, respectively. The best cut-off values that achieved the highest sensitivity and specificity for SEstrain ratio, SWEmean avg, SWEmax avg, and SWEratio avg were 3.91, 113 kPa, 123.5 kPa, and 7.32, respectively. Quantitative parameter of SE showed comparable diagnostic performance with quantitative parameters of SWE.

Use of Shear Wave Elastography in the Sonographic Triage of Thyroid Nodules: Feasibility Study in a Series of Lesions Already Selected for Fine Needle Aspiration.

The aim of this study was to evaluate the application of shear wave elastography (SWE) in the routine management of thyroid nodules, as a possible additional tool to the standard sonographic triage. A total of 248 consecutive patients scheduled for ultrasound-guided thyroid fine-needle aspiration were included in the study. The presence of a pure colloid lesion was an exclusion criterion. Absolute and relative SWE stiffness measurements on color-coded elastograms, expressed in kilopascals and meters per second, were correlated with radiologic and pathologic features. SWE values in thyroid nodules were significantly higher than normal thyroid tissue (P = .0001), proving the different elastic properties of the pathologic tissues. Regarding the radiologic characteristics of the nodules, SWE highest values were associated with the largest lesions (P = .0105) but independent from sonographic and Doppler findings. The SWE elasticity was not influenced by the characteristics of the biopsy smears. The final correlation between the SWE results and the pathologic diagnoses showed a trend in stiffness from tender tumors (follicular adenoma) to papillary thyroid carcinoma (P = .016). SWE allows the identification of nodules within normal parenchyma; however, the present study does not confirm the potential role in differentiating between benign and malignant thyroid nodules.

Efficacy of Shear-Wave Elastography for Detecting Postoperative Cervical Lymph Node Metastasis in Papillary Thyroid Carcinoma.

Aims To evaluate shear-wave elastography (SWE) as a tool to detect postoperative cervical lymph node (LN) metastasis in patients with papillary thyroid carcinoma (PTC). Methods Forty-three LNs of 43 patients with PTC undergoing ultrasound (US) and SWE before ultrasound-guided fine-needle aspiration (FNA) for the evaluation of postoperative cervical LN recurrences were analyzed. The mean (EMean), minimum (EMin), maximum (EMax), and standard deviation (ESD) of SWE elasticity indices were measured. Results Among 43 indeterminate or suspicious LNs, 12 were malignant and 31 were benign. The EMean, EMin, EMax, and ESD values were significantly higher in malignant LNs than in benign LNs (EMean: 37.1 kPa in malignant versus 11.8 kPa in benign LNs, P < 0.001; EMin: 11.3 kPa versus 5.1 kPa, P = 0.046; EMax: 50.5 kPa versus 23.7 kPa, P < 0.001; and ESD: 7.8 kPa versus 4.1 kPa, P = 0.006). EMax had the highest accuracy (93.0%) when applied with a cut-off value of 37.5 kPa. It had a positive likelihood ratio of 25.83 and a diagnostic odds ratio of 150.0. Conclusions The shear elasticity index of EMax, with higher likelihood ratios for malignant LNs, may help identify postoperative cervical LN metastasis in PTC patients with indeterminate or suspicious LNs.

Reliability of ultrasound shear-wave elastography in assessing low back musculature elasticity in asymptomatic individuals

Patients with low back pain commonly exhibit impaired morphology and function of spinal musculature that may be quantifiable using shear-wave elastography (SWE). The purpose of this study was to assess the intra-rater and test-retest reliability of SWE elasticity measures of the lumbar erector spinae and multifidus muscles during rest and differing levels of contraction in asymptomatic individuals. This single-group repeated-measures design involved a baseline measurement session and a follow-up session 3 days later. The lumbar multifidus was imaged at rest and during three levels of contraction (minimal, moderate, and maximum). The lumbar erector spinae (illiocostalis and longissimus muscles) were imaged at rest only. Overall reliability estimates were fair to excellent with ICCs ranging from 0.44 to 0.92. Reliability was higher in the lumbar multifidus muscles than the erector spinae muscles, slightly higher during contraction than during rest, and substantially improved by using the mean of 3 measurements. By reliably quantifying impaired spinal musculature, SWE may facilitate an improved understanding of the etiology and treatment of low back pain and other muscle pain-related conditions such as trigger points and fibromyalgia.

Shear wave elastography combined with the thyroid imaging reporting and data system for malignancy risk stratification in thyroid nodules.

To retrospectively evaluate the diagnostic performance of shear wave elastography (SWE) and thyroid imaging reporting and data system (TI-RADS) in differentiating malignant and benign thyroid nodules. A total of 313 thyroid nodules in 227 patients were included. All thyroid nodules were underwent SWE and TI-RADS before fine needle aspiration biopsy and/or surgery. SWE elasticity indices of the maximum (Emax), mean (Emean), minimum (Emin) and elastic ratio (ER) in thyroid nodules were measured. Nodules with solid component, marked hypoechogenicity, poorly defined margins, micro-calcifications, and a taller-than-wide shape were classified as suspicious at gray-scale ultrasonography. The level of TI-RADS was determined according to the number of suspicious ultrasonography features. The combined methods of SWE and TI-RADS in thyroid nodules were calculated. In the 313 nodules, 194 were malignant, and 119 were benign. SWE and TI-RADS were significantly higher in malignant nodules than benign nodules (P < 0.001). The most accurate SWE cut-off value, 51.95 kPa for Emax, achieved a sensitivity of 81.44% and a specificity of 83.19% for discriminating malignant nodules from benign nodules. There are two methods in combination with SWE and TI-RADS. The one is “tandem” method, which has a higher specificity (95.80%), positive likelihood ratio (18.16) and positive predictive value (96.73%). The other one is “parallel” method, which shows sensitivity (94.85%), negative likelihood ratio (0.07) and negative predictive value (90.00%).We believe that the methods could be used as a simple tool to stratify the risk of thyroid nodules accurately.

Does Shear Wave Elastography Provide Additional Value in the Evaluation of Thyroid Nodules That Are Suspicious for Malignancy?

We aimed to determine whether the integration of shear wave elastography (SWE) with conventional ultrasonography (US) improves diagnostic performance for suspicious thyroid lesions. For 215 thyroid lesions in 185 patients classified as Thyroid Imaging Reporting and Data System category 4 or 5 according to the findings of conventional US, SWE elasticity indices were automatically calculated. A receiver operating characteristic curve analysis was used to determine the threshold. Thyroid Imaging Reporting and Data System categories were upgraded for high-stiffness nodules and unchanged for low- and normal-stiffness nodules. The diagnostic performances were assessed and compared with histologic findings. Intraobserver and interobserver variability of SWE was assessed. Elasticity indices were significantly higher in malignant versus benign nodules (P≤ .001). The minimum elasticity index (cutoff, 40.7 kPa) of the stiffest part combined with conventional US showed the highest area under the curve (0.774; 95% confidence interval, 0.682-0.866) but was not superior to conventional US (0.791; 95% confidence interval, 0.706-0.876; P = .48). Combined with the standard deviation of the elasticity index for the whole lesion (cutoff, 6.8 kPa), US yielded the highest sensitivity (95.5%; P < .001) and lowest specificity (42.1%; P < .001). Sensitivity increased and specificity decreased by adding any other SWE elasticity index. The intraobserver and interobserver reliability of SWE was fair to excellent according to the interclass correlation coefficients, with correlation coefficients of 0.765 to 0.846 (all P < .001). The SWE elasticity indices of malignant thyroid nodules were significantly high. Adding SWE to conventional US did not improve diagnostic performance.

Utility of real-time shear wave elastography for assessing liver fibrosis in patients with chronic hepatitis C infection without cirrhosis: Comparison of liver fibrosis indices.

To clarify the diagnostic impact of liver fibrosis except for cirrhosis identified using shear wave elastography (SWE) in chronic hepatitis C (CHC) patients, and to compare the performance in diagnosing liver fibrosis among SWE and liver fibrosis indices. A total of 55 CHC patients who underwent liver biopsy were analyzed. The diagnostic performance for identifying significant liver fibrosis (F2-F3) for SWE, FIB-4 index, aspartate aminotransferase-to-platelet ratio index (APRI) and Forns' index was assessed using receiver-operator curve (ROC) analysis. The median SWE elasticity value, FIB-4 index, APRI and Forns' index in the F0-F1 and F2-F3 groups were 6.3 kPa and 13.1 kPa; 1.52 and 4.45; 0.41 and 1.43; and 7.69 and 8.85, respectively (P < 0.001 for all four methods). Multivariate analysis showed that SWE was independently associated with the presence of significant liver fibrosis (odds ratio, 2.52; 95% confidence interval, 1.49-4.28; P < 0.001). The area under the ROC curve for SWE in diagnosing significant liver fibrosis was 0.94, indicating high diagnostic value, compared with 0.86, 0.88 and 0.83, for the FIB-4 index, APRI and Forns' index, respectively, which corresponds to moderate diagnostic value. The accuracy of SWE, FIB-4 index, APRI and Forns' index for diagnosing significant liver fibrosis was 90.9%, 76.4%, 74.5% and 67.2%, respectively. SWE has excellent ability for diagnosing significant liver fibrosis in CHC even when patients with cirrhosis are excluded. The diagnostic performance of SWE is superior to that of three liver fibrosis indices.

Shear wave elastography in evaluation of cervical lymph node metastasis of papillary thyroid carcinoma: elasticity index as a prognostic implication.

The aim of this study was to evaluate the usefulness of shear wave elastography (SWE) for predicting cervical lymph node (LN) metastasis and the prognostic implication of SWE as histopathologic factors of papillary thyroid carcinoma (PTC). Eighty-four LNs of 66 patients with PTC underwent B-mode ultrasonography (BUS) and SWE before ultrasound-guided fine-needle aspiration biopsy or preoperative evaluation. SWE elasticity indices (EI) of mean (Emean), minimum (Emin), maximum (Emax) and the ratio of Emean in LNs and surrounding muscle (Emean-m) were measured at the stiffest portion of LNs (kPa). SWE EI were correlated with the pathologic diagnosis and the histopathologic findings, including number and size of metastatic LNs, the ratio of the number of metastatic LN/dissected LN, and the presence of extranodal extension. Diagnostic performances of SWE EI and BUS for predicting LN metastasis were assessed using receiver operating curve analysis. All SWE EI were significantly higher in metastatic LNs than in benign LNs (p < 0.005). Combined Emean [area under the curve (AUC) 0.811] or Emin (AUC 0.812) with BUS showed significantly higher AUC than BUS (0.738) for predicting metastatic LNs (p = 0.041 and 0.033, respectively). The number of positive LNs/dissected LNs and the largest LN size were significantly correlated with SWE EI (p < 0.05 and p < 0.005, respectively). Metastatic LNs with extranodal extension showed significantly higher SWE EI (p < 0.005) than those without extranodal extension. Combined use of SWE and BUS was adjunctive to the diagnostic performance of BUS for the prediction of LN metastasis of PTC, and quantitative SWE could predict pathologic prognostic factors of LN metastasis of PTC.

Shear wave elastography of thyroid nodules for the prediction of malignancy in a large scale study

The purpose of this study is to validate the usefulness of shear wave elastography (SWE) in predicting thyroid malignancy with a large-scale quantitative SWE data. This restrospective study included 476 thyroid nodules in 453 patients who underwent gray-scale US and SWE before US-guided fine-needle aspiration biopsy (US-FNA) or surgical excision were included. Gray-scale findings and SWE elasticity indices (EIs) were retrospectively reviewed and compared between benign and malignant thyroid nodules. The optimal cut-off values of EIs for predicting malignancy were determined. The diagnostic performances of gray-scale US and SWE for predicting malignancy were analyzed. The diagnostic performance was compared between the gray-scale US findings only and the combined use of gray-scale US findings with SWEs. All EIs of malignant thyroid nodules were significantly higher than those of benign nodules (p≤.001). The optimal cut-off value of each EI for predicting malignancy was 85.2kPa of Emean, 94.0kPa of Emax, 54.0kPa of Emin. Emean (OR 3.071, p=.005) and Emax (OR 3.015, p=.003) were the independent predictors of thyroid malignancy. Combined use of gray-scale US findings and each EI showed elevated sensitivity (95.0-95.5% vs 92.9%, p≤.005) and AUC (0.820-0.834 vs 0.769, p≤.005) for predicting malignancy, compared with the use of only gray-scale US findings. Quantitative parameters of SWE were the independent predictors of thyroid malignancy and SWE evaluation combined with gray-scale US was adjunctive to the diagnostic performance of gray-scale US for predicting thyroid malignancy.