Shear Wave Elastography Examinations Research Articles

Two-dimensional shear-wave elastography and conventional US: the optimal evaluation of liver fibrosis and cirrhosis.

To evaluate the individual and combined performances of two-dimensional (2D) shear-wave elastography (SWE) and conventional ultrasonography (US) in assessing liver fibrosis and cirrhosis to determine when 2D SWE should be added to routine US. This prospective study was approved by the institutional ethics committee, and the patients provided written informed consent. Between April 2012 and March 2013, conventional US and 2D SWE examinations were performed in 198 patients (mean age, 37.7 years; age range, 18-67 years) with chronic liver disease. Liver biopsy was used as a reference standard for 167 patients; the other 31 patients had decompensated liver cirrhosis. Receiver operating characteristic (ROC) curves were obtained to assess the diagnostic performance. Differences between the areas under the ROC curves (AUCs) were compared by using a Delong test. Two-dimensional SWE was significantly superior to US in diagnosis of significant fibrosis (score of F2 or greater) (AUC, 0.862 vs 0.725; P = .001) and early cirrhosis (score of F4) (AUC, 0.926 vs 0.789; P = .007). Combining 2D SWE with US did not increase the performance of depicting either significant fibrosis or liver cirrhosis (P = .713 and 0.410, respectively) relative to 2D SWE alone. There was no significant difference between 2D SWE and US in diagnosis of decompensated cirrhosis (AUC, 0.878 vs 0.925; P = .323). In addition, combining 2D SWE with US did not increase the performance relative to that of US alone (P = .372). Conventional US is sufficient to detect decompensated cirrhosis. Two-dimensional SWE is significantly superior to US in detecting liver fibrosis. Combining 2D SWE and US did not improve the diagnostic performance for either fibrosis or cirrhosis.

Smooth muscle cells of penis in the rat: noninvasive quantification with shear wave elastography.

Purpose. Smooth muscle cells (SMCs) of cavernosum play an important role in erection. It is of great significance to quantitatively analyze the level of SMCs in penis. In this study, we investigated the feasibility of shear wave elastography (SWE) on evaluating the level of SMCs in penis quantitatively. Materials and Methods. Twenty healthy male rats were selected. The SWE imaging of penis was carried out and then immunohistochemistry analysis of penis was performed to analyze the expression of alpha smooth muscle actin in penis. The measurement index of SWE examination was tissue stiffness (TS). The measurement index of immunohistochemistry analysis was positive area percentage of alpha smooth muscle actin (AP). Results. Sixty sets of data of TS and AP were obtained. The results showed that TS was significantly correlated with AP and the correlation coefficient was −0.618 (p < 0.001). The result of TS had been plotted against the AP measurements. The relation between the two results has been fitted with quadric curve; the goodness-of-fit index was 0.364 (p < 0.001). Conclusions. The level of SMCs in penis was successfully quantified in vivo with SWE. SWE can be used clinically for evaluating the level of SMCs in penis quantitatively.

Does shear wave ultrasound independently predict axillary lymph node metastasis in women with invasive breast cancer?

Shear wave elastography (SWE) shows promise as an adjunct to greyscale ultrasound examination in assessing breast masses. In breast cancer, higher lesion stiffness on SWE has been shown to be associated with features of poor prognosis. The purpose of this study was to assess whether lesion stiffness at SWE is an independent predictor of lymph node involvement. Patients with invasive breast cancer treated by primary surgery, who had undergone SWE examination were eligible. Data were retrospectively analysed from 396 consecutive patients. The mean stiffness values were obtained using the Aixplorer® ultrasound machine from SuperSonic Imagine Ltd. Measurements were taken from a region of interest positioned over the stiffest part of the abnormality. The average of the mean stiffness value obtained from each of two orthogonal image planes was used for analysis. Associations between lymph node involvement and mean lesion stiffness, invasive cancer size, histologic grade, tumour type, ER expression, HER-2 status and vascular invasion were assessed using univariate and multivariate logistic regression. At univariate analysis, invasive size, histologic grade, HER-2 status, vascular invasion, tumour type and mean stiffness were significantly associated with nodal involvement. Nodal involvement rates ranged from 7 % for tumours with mean stiffness <50 kPa to 41 % for tumours with a mean stiffness of >150 kPa. At multivariate analysis, invasive size, tumour type, vascular invasion, and mean stiffness maintained independent significance. Mean stiffness at SWE is an independent predictor of lymph node metastasis and thus can confer prognostic information additional to that provided by conventional preoperative tumour assessment and staging.

Comparison of Diagnostic Value of Conventional Ultrasonography and Shear Wave Elastography in the Prediction of Thyroid Lesions Malignancy

IntroductionThyroid nodular disease (TND) is a very common disorder. However, since the rate of malignancy is reported to be 3-10%, only a minority of patients require aggressive surgical treatment. As a result, there is a need for diagnostic tools which would allow for a reliable differentiation between benign and malignant nodules. Although a number of conventional ultrasonographic (US) features are proved to be markers of malignancy, Shear Wave Elastography (SWE) is considered to be an improvement of conventional US. The aim of this study was to compare conventional US markers and SWE diagnostic values in the differentiation of benign and malignant thyroid nodules.Materials and MethodsAll patients referred for thyroidectomy, irrespective of the indications, underwent a US thyroid examination prospectively. Patients with TND were included into the study. Results of the US and SWE examinations were compared with post-surgical histopathology. ResultsOne hundred and twenty two patients with 393 thyroid nodules were included into the study. Twenty two patients were diagnosed with cancer. SWE turned out to be a predictor of malignancy superior to any other conventional US markers (OR=54.5 using qualitative scales and 40.8 using quantitative data on maximal stiffness with a threshold of 50 kPa). ConclusionsAlthough most conventional US markers of malignancy prove to be significant, none of them are characterized by both high sensitivity and specificity. SWE seems to be an important step forward, allowing for a more reliable distinction of benign and malignant thyroid nodules. Our study, assessing SWE properties on the highest number of thyroid lesions at the time of publication, confirms the high diagnostic value of this technique. It also indicates that a quantitative evaluation of thyroid lesions is not superior to simpler qualitative methods.