Virtual Touch Tissue Imaging Research Articles

ARFI ELASTOGRAPHY IN THE DIAGNOSIS OF THYROID NODULES

Objective: To describe the sonography characteritics of the thyroid nodules using Acoutic Radiation Force Impulse Imaging (ARFI), and to evaluate the role of ARFI technique combination with 2D Ultrasound in diagnosing thyroid nodules. Methods: 2D Ultrasound and ARFI Elatography were caried out in 63 patients who have thyroid nodules. Images of 2D Ultrasound were classified according to Russ G. (French TIRADS). ARFI Elastography was performed by 2 techniques: “ Virtual Touch tissue imaging” in order to image of strain distribution and “Virtual Touch tissue quantification Imaging” to measure the shear wave velocity (SWV) in the tissue. Strain distribution was classified according to Xu’s VTI grading method. SWV was measured in the solid portions or suspicious regions of a nodule, avoiding cystic portions or calcifications. According to the results of pathology, we determine and compare the value between 2D Ultrasound plus ARFI elastography and 2D Ultrasound alone. Results: 63 patients with thyroid nodules: 14 malignant nodules and 49 benign nodules. The mean SWV of benign nodules were 1.78±1.22 m/s, the mean SWV of malignant nodules were 7.09±2.87 m/s. The best cut-off point for SWV was 2.4 m/s. For VTI, grade IV was the best cut-off value in differentiation of benign and malignant thyroid nodules. 2D Ultrasound plus VTI and 2D Ultrasound plus VTQ: Se 100% and 100%, Sp 87.8% and 85.7%, PPV 70% and 66.7%, NPV 100% and 100%, Acc 90.5 % and 88.9% (K=0.761 and K=0.727). Conclusions: In addition to the morphologic characteristics of thyroid nodules, ARFI provides information about lesion’s tissue elasticity, which can be useful tool in diferential diagnosis of thyroid nodules. Key words: Acoustic Radiation Force Impulse Imaging (ARFI), thyroid nodules

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.

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 (SWSmean and SWSmax) 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, SWSmean 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.

Association Between Shear Wave Elastography of Virtual Touch Tissue Imaging Quantification Parameters and the Ki‐67 Proliferation Status in Luminal‐Type Breast Cancer

To evaluate the association between shear wave elastography parameters using virtual touch tissue imaging quantification (VTIQ) and the Ki-67 index in luminal-type breast cancer. Eighty-one patients with 82 lesions of pathologic confirmed luminal-type breast cancer underwent virtual touch tissue imaging quantification examination before surgery between December 2015 and June 2016. Patients were divided into 2 groups according to the Ki-67 index (≥14% versus < 14%), which is used to define luminal type B and luminal type A, respectively. The mean shear wave velocity (SWVmean ) and lesion-to-adjacent tissues ratio (SWV ratio) were calculated for each lesion. The SWVmean , SWV ratio, histologic grade, axillary lymph node involvement, and lymphovascular invasion showed a significant positive association with a high Ki-67 index (all P < .05). Receiver operating characteristic curve analysis for the differential diagnosis between high (≥14%) and low (<14%) Ki-67 groups displayed that the optimal cutoff value for SWVmean and SWV ratio were 3.99 meters per second and 2.861, with sensitivity 94% and 72%, specificity 40.6% and 56.2%, and area under the receiver operating characteristic curve of 0.689 and 0.651, respectively. Univariate analysis showed that SWVmean (P = .005), SWV ratio (P = .029), histologic grade (P = .011), presence of axillary node involvement (P = .004), and lymphovascular invasion (P = .008) were significantly associated with high Ki-67 status. Multivariable analysis displayed that SWVmean (hazard ratio [HR], 1.459, 95% confidence interval [CI], 1.028-2.072; P = .035), histologic grade (HR, 4.105; 95% CI, 1.142-14.763; P = .031), and presence of axillary node involvement (HR, 3.75; 95% CI, 1.228-11.453; P = .020) maintained significance for predicting high Ki-67 status. The SWVmean using the virtual touch tissue imaging quantification method showed significant correlation with the Ki-67 index, suggesting the potential to assess tumor proliferation status in luminal-type breast cancer with a noninvasive manner.

Effects of chronic flexed wrist posture on the elasticity and crosssectional area of the median nerve at the carpal tunnel among chronic stroke patients.

To investigate the effects of chronic flexed wrist posture following spasticity on the elasticity and cross-sectionalarea (CSA) of the median nerve at the carpal tunnel among chronic stroke patients. This prospectivestudy included 24 consecutive patients (mean age, 56.5±11.56 years) with unilateral wrist spasticity following a stroke in achronic phase. The CSA of the median nerve was measured by ultrasound (US). The elasticity was measured by Virtual Touchtissue imaging quantification (VTIQ; Siemens, Erlangen, Germany). SWV and CSA of the median nerves of the affected andunaffected sides for each patient were compared. The correlations between duration of time since the stroke, SWV and CSA of the median nerve were assessed. The interobserver agreement was assessed. The CSA of the median nerve at the affected side was significantly lower than that of the unaffected side (p = 0.03). The SWV of the median nerve at the affected side was significantly higher than that on the unaffected side (p < 0.001). The interobserver agreement was excellent for both CSA and SWV measurements. There was a negatively fair correlation between CSA at the affected side and duration of time since stroke (r = -0.58, p < 0.05). The SWV of the median nerve at the affected side was not correlated with the duration of time since stroke (r ≤ 0.3, p ≥ 0.05). These results suggest that chronic flexed wrist posture may cause atrophy of the median nerve due to chronic compression after stroke and increase in the stiffness of the median nerve.

Combination of conventional ultrasonography and virtual touch tissue imaging quantification for differential diagnosis of breast lesions smaller than 10 mm.

To determine the value of combining conventional ultrasonography with virtual touch tissue imaging quantification (VTIQ) for differential diagnosis of breast lesions smaller than 10 mm. A total of 98 breast lesions smaller than 10 mm were examined by conventional ultrasound and VTIQ using a Siemens ACUSON S3000 ultrasound machine. Pathologic diagnosis was established after surgery or fine needle biopsy. Malignant lesions were characterized by taller-than-wide shape, poorly circumscribed margin, and marked hypoechogenicity. The mean VTIQ shear wave velocity (SWV) value of malignant lesions was 4.88±1.87 m/s (range, 1.75-9.34 m/s), significantly higher than that of benign lesions (2.68±1.02 m/s; range, 1.18-4.67 m/s). The optimal cutoff SWV value was 3.27 m/s, with sensitivity, specificity, diagnostic accuracy, positive predictive value (PPV), and negative predictive value (NPV) of 86.20%, 95.65%, 92.86%, 89.29%, and 94.29%, respectively. The combination of SWV >3.27 m/s plus the US feature of poorly circumscribed margin had the highest sensitivity (93.33%) and specificity (100%) for diagnosis of malignant breast lesions. Features such as taller-than-wide shape, poorly circumscribed margin, and marked hypoechogenicity on conventional US, and SWV >3.27 m/s on VTIQ, are indicators of malignancy in breast lesions with diameter <10 mm. The combination of poorly circumscribed margin and SWV >3.27 m/s provides the highest specificity and diagnostic accuracy.

Assessment of Virtual Touch Tissue Imaging Quantification and the Ultrasound Thyroid Imaging Reporting and Data System in Patients With Thyroid Nodules Referred for Biopsy.

To evaluate the diagnostic performance of Virtual Touch tissue imaging quantification (VTIQ; Siemens Medical Solutions, Mountain View, CA) in combination with the Thyroid Imaging Reporting and Data System (TI-RADS) for assessing thyroid nodules referred for biopsy. A total of 197 surgically or cytologically proven thyroid nodules in 187 patients were included. Nodules evaluated by conventional ultrasound (US) and VTIQ examinations were classified into US TI-RADS categories. The shear wave velocity (SWV) on VTIQ was assessed, and the cutoff value was obtained from a receiver operating characteristic curve analysis. Diagnostic performances of conventional US, VTIQ, and their combination were compared. There were 134 benign and 63 malignant nodules. The sensitivity and specificity for the US TI-RADS were 98.4% and 20.1%, respectively. The areas under the receiver operating characteristic curves for the mean, maximum, minimum, and ratio of the SWV were 0.818, 0.805, 0.799, and 0.728. With a cutoff value of 2.90 m/s, the sensitivity and specificity of the mean SWV were 71.4% and 82.8%. By applying this value or less as a standard for downgrading TI-RADS category 4a to category 3 lesions, the specificity significantly rose from 20.1% to 47.0% (P < .001) without a loss of sensitivity. The additional application of VTIQ can improve the specificity of the TI-RADS for evaluating thyroid nodules without a loss of sensitivity.

Virtual touch tissue imaging and quantification: value in malignancy prediction for complex cystic and solid breast lesions

This study was aimed to evaluatethe usefulness of conventional ultrasound (US) and US elastography, including the latest virtual touch tissue imaging and quantification (VTIQ), in malignancy prediction for complex cystic and solid breast lesions. Eighty-nine complex cystic and solid breast lesions were subject to conventional US and US elastography, including strain elastography (SE), virtual touch tissue imaging (VTI) and VTIQ. Among the 89 lesions, thirty-four (38.2%) lesions were malignant and 55 (61.8%) lesions were benign. Sixteen variables were subject to multivariate logistic regression analysis. Pattern 4b in VTI (odds ratio, OR:15.278), not circumscribed margin of lesion (OR:12.346), SWS mean >4.6 m/s in VTIQ (OR:11.896), and age elder than 50 years (OR:6.303) were identified to be independent predictors for malignancy. In receiver operating characteristic (ROC) curve analyses, associated areas under the ROC curve (Az) for conventional US could be significantly elevated, from 0.649 to 0.918, by combining with US elastography (p < 0.0001). The combined diagnostic method was able to improve the specificity (32.7% vs. 87.3%, p < 0.0001) without sacrificing the sensitivity (97.1% vs. 85.3%, p = 0.075). Both conventional US and US elastography contribute substantially to malignancy prediction in complex cystic and solid lesions. The diagnostic efficacy of conventional US in terms of Az and specificity could be significantly improved by combining with US elastography.

Association of conventional ultrasound, elastography and clinicopathological factors with axillary lymph node status in invasive ductal breast carcinoma with sizes > 10 mm.

BackgroundTo evaluate whether conventional ultrasound, elastography [conventional strain elastography of elasticity imaging, acoustic radiation force impulse induced strain elastography of virtual touch tissue imaging, and a novel two-dimensional shear wave elastography of virtual touch tissue imaging quantification] and clinicopathological factors are associated with axillary lymph node metastasis in invasive ductal breast carcinoma with sizes > 10 mm.Materials and MethodsWe evaluated 150 breast lesions from 148 patients using the above methods and the clinicopathological factors. Univariate and multivariate logistic regression analysis were performed to determine the axillary lymph node metastasis risk factors. Diagnostic performance was evaluated using receiver operating characteristic curve analysis.ResultsSixty-three tumors (42%) were node-positive, 87 (58%) were node-negative. Aspect ratio, virtual touch tissue imaging grade, shear wave velocity, pathological invasive tumor size, and histological grade maintained independent significance in predicting nodal involvement. The mean tumor shear wave velocitys (4.60, 6.49, 7.16) increased in proportion to metastatic node number (0, 1–3, ≥ 4, respectively; P < 0.001). For all tumors in this study, the cut-off shear wave velocity was 6.16 m/s and was associated with 64.1% sensitivity, 78.0% specificity and an area under the ROC curve of 0.799 (95% confidence interval, 0.731–0.868).ConclusionsAspect ratio, virtual touch tissue imaging grade, shear wave velocity, pathological invasive tumor size and histological grade are independently associated with axillary lymph node metastasis in invasive ductal breast carcinoma with sizes > 10 mm.

Efficacy of acoustic radiation force impulse elastography in differentiation of benign and malignant lymph nodes

Abstract Aims and Objectives: Aim of this study was to assess the clinical usefulness of Acoustic Radiation Force Impulse (ARFI) elastography imaging in differentiating benign and malignant/metastatic superficial nodes. Methods and Materials: ARFI elastography (Siemens Medical Solutions, Mountain View, CA) using Virtual touch Tissue Imaging (VTI) technique was performed and Shear wave velocity (m/sec) was measured in 85 patients (mean age, 49 years; range, 16–72 years) with 126 lymph nodes (96 axillary, 21 cervical and 9 inguinal nodes) which were biopsied and histo-pathologically correlated. Results: Of 126 nodes, 71 were benign (64 reactive and 7 koch's) and 55 were malignant (40 metastases and 15 lymphoma). The mean ARFI value of malignant nodes ±SD (4.42 ± 2.60) were significantly higher than the benign nodes (1.76 ± 0.44), with P &lt;0.001. With the use of Receiver Operating Characteristic (ROC) curve, the cut off SWV was estimated to be 2.45m/s with sensitivity of 83.6%, specificity of 91%, and accuracy of 93.7 % while the conventional US based short axis diameter (SAD) measurement with cut off value of 10mm, showed the sensitivity of 62 %, specificity of 87% and accuracy of 87%. Conclusion: Acoustic radiation force impulse elastography is feasible for superficial lymph nodes and provides quantitative elasticity measurements, which may complement B-mode ultrasound and potentially improve the differentiation of benign and malignant/metastatic lymph nodes.

A Risk Model based on Ultrasound, Ultrasound Elastography, and Histologic Parameters for Predicting Axillary Lymph Node Metastasis in Breast Invasive Ductal Carcinoma

To develop a risk model for predicting axillary lymph node metastasis (LNM) in patients with breast invasive ductal carcinoma (IDCs) using ultrasound (US), US elastography of virtual touch tissue imaging (VTI) and virtual touch tissue imaging & quantification (VTIQ), and histologic parameters. This study included 162 breast IDCs in 162 patients. Univariate and multivariate analyses were used to identify the risk factors and a risk model was created. The results found that 64 (39.5%) of 162 patients had axillary LNMs. The risk score (RS) for axillary LNM was defined as following: RS = 1.3 × (if lesion size ≥20 mm) + 2.6 × (if taller than wide shape) + 2.2 × (if VTI score ≥5) + 3.9 × (if histological grade III) + 1.9 × (if positive C-erbB-2). The rating system was divided into 6 stages (i.e. Stage I, Stage II, Stage III, Stage IV, Stage V, and Stage VI) and the associated risk rates in terms of axillary LNM were 0% (0/19), 6.1% (2/33), 7.7% (3/39), 65.5% (19/29), 92.3% (24/26), and 100% (16/16), respectively. The risk model for axillary LNM established in the study may facilitate subsequent treatment planning and management in patients with breast IDCs.

The correlation between HER-2 expression and the CEUS and ARFI characteristics of breast cancer.

ObjectiveThe purpose of the present study was to explore the correlation between the contrast-enhanced ultrasound (CEUS) and acoustic radiation force impulse (ARFI) characteristics of breast cancers and the expression of human epidermal growth factor receptor 2 (HER-2).MethodsHER-2 expression levels in the tumor masses of 167 clearly diagnosed cases of breast cancer were measured and analyzed. The enhancement features and time intensity curve (TIC) of CEUS and virtual touch tissue imaging (VTI) and virtual touch tissue quantification (VTQ) technology of ARFI were employed to analyze the relationship between HER-2 expression and the CEUS and ARFI characteristics of breast cancer.Results(1) Statistically significant differences in the distribution of the contrast agent, perforator blood flow, the overranging phenomenon and perfusion defects between the study groups with different HER-2 expression levels (P < 0.05) were observed on CEUS. In addition, statistically significant differences in the TIC peak time (PT), slope of the ascending branch (K) and area under the curve (AUC) were found in the groups expressing different levels of HER-2 (P < 0.05). In contrast, the degree of contrast agent enhancement and TIC peak intensity (PI) were found to be independent of the expression status of HER-2, as they were not statistically significant (P > 0.05). (2) Statistically significant differences in the VTQ results between the groups with different HER-2 expression levels were found (P < 0.05). However, no statistically significant differences in VTI image characteristics were detected between the groups expressing different levels of HER-2 (P > 0.05).ConclusionA correlation was found between the CEUS and ARFI characteristics of breast cancer and HER-2 expression levels. This correlation was principally reflected in perfusion defects, perforator blood flow, PI, PT, K and VTQ.

Acoustic Radiation Force Impulse Imaging of the Transplant Kidney: Correlation Between Cortical Stiffness and Arterial Resistance in Early Post-transplant Period

BackgroundAcoustic radiation force impulse (ARFI) imaging is a noninvasive imaging modality for quantitative assessment of tissue stiffness. This study utilized ARFI imaging to assess the stiffness of a transplant renal cortex within the first month after renal transplantation and to explore the correlation between the cortical stiffness and arterial resistance of the transplant kidney. MethodsForty renal transplant recipients (male/female = 26/14; mean age: 45.3 years; deceased donor/living related donor = 27/13) were included in this study. ARFI imaging with virtual touch tissue imaging quantification was applied to assess the stiffness of the transplant renal cortex by using a linear ultrasound transducer. Arterial resistance was acquired by spectral Doppler examination of the main artery and intrarenal arteries of the transplant kidney using a curvilinear ultrasound transducer. ResultsThe stiffness of transplant renal cortex was expressed as shear wave velocity (m/s). The mean value of cortical stiffness was 3.19 ± 1.01 m/s (range: 1.55–5.54). The stiffness of transplant renal cortex was positively correlated with the resistance index of the main renal artery (r = 0.55, P = .001), segmental artery (r = 0.43, P = .005), and interlobar artery (r = 0.42, P = .006). ConclusionThe stiffness of a transplant renal cortex is positively correlated with the arterial resistance of the renal transplant in the early post-transplant period. This result indicates that, in addition to renal fibrosis, the stiffness of the transplant renal cortex is also influenced by the hemodynamics of the transplant kidney.

Comparison of Virtual Touch Tissue Imaging & Quantification (VTIQ) and Toshiba shear wave elastography (T-SWE) in diagnosis of thyroid nodules: Initial experience.

The aim of this study was to compare the diagnostic performance of two different 2D shear wave speed imaging techniques of Virtual Touch Tissue Imaging & Quantification (VTIQ) and Toshiba shear wave elastography (T-SWE) in predicting malignant thyroid nodules (TNs). 75 TNs in 75 patients which were subject to both VTIQ and T-SWE examinations were enrolled and analyzed. Shear wave speed (SWS) values on VTIQ and T-SWE were computed (SWS_max, min, mean and median). Area under the receiver operating characteristic (AUROC) curve was obtained to assess the diagnostic performance. The AUROC for VTIQ was the highest with SWS_min whereas for T-SWE was SWS_max (0.774 versus 0.851; p > 0.05). The AUROC, sensitivity and negative predictive value (NPV) corresponding to SWS_max for VTIQ were significantly lower than those for T-SWE (0.717 versus 0.851, 61.5% versus 92.3% and 78.7% versus 94.3%; all p < 0.05). However, no significant differences were found between AUROC with SWS_min, SWS_mean, or SWS_median for VTIQ and SWS_max for T-SWE (all p > 0.05). In general, VTIQ is equal to T-SWE for diagnosis of TNs. In the clinical practice, the selection of SWS_max should be avoided in VTIQ whereas should be selected in T-SWE.

Conventional US combined with acoustic radiation force impulse (ARFI) elastography forprediction of triple-negative breast cancer and the risk of lymphatic metastasis.

To evaluate the combination of conventional ultrasound (US) and acoustic radiation force impulse (ARFI) elastography in predicting triple-negative breast cancer and the likelihood of lymphatic metastasis. A total of 178 women presenting from May 2013 to September 2015 with pathologically proven triple-negative (n = 60) or hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer (n = 118) were reviewed. Conventional US and ARFI imaging including Virtual touch tissue image (VTI) and Virtual Touch tissue Quantification (VTQ), were performed for each breast nodule. Parameters collected included patient age, lymph node involvement, histological grade, tumor subtype, appearance on conventional US, shear wave velocity (SWV) value, VTI score and the boundary on VTI. The ARFI findings were compared with the pathological findings. Younger age (P < 0.001), higher histological grade (P < 0.001), lymphatic metastasis (P < 0.001), more nodes involved (P = 0.001), larger tumor size (P = 0.008), regular shape (P = 0.032), high VTI score (P = 0.006), unclear VTI boundary (P = 0.033), SWV ≥3.51 m/s (P = 0.015) were significantly associated with triple-negative breast cancer. High VTI score (P = 0.004) and a high SWV ≥4.15 m/s (P = 0.002) were significantly associated with lymphatic metastasis. Conventional US combined with ARFI may be used to predict triple-negative breast cancer. Those cancers with higher SWV and the high VTI score have a higher likelihood of lymphatic metastasis.

The relationship between shear wave velocity and the ratio of typeI/typeIII collagen fiber in the carotid plaques

Objective To assess the correlation between the shear wave velocity(SWV) and the ratio of typeⅠ /typeⅢ collagen fibers in plaques using virtual touch tissue imaging quantification(VTIQ). Methods Fifty four patients (54 plaques) who scheduled to carotid endarterectomy(CEA) were enrolled in this study. Their carotid plaques were preoperatively examined using VTIQ. The value of SWE of each plaque was obtained. The SWV of the plaque was evaluated by VTIQ. The endarterectomy specimens were transferred to the pathological department immediately after surgery to evaluate the plaque types and the distribution of collagen fibers in plaques. According to HE staining, the 54 plaques were divided into stable and unstable group. Results Among 54 plaques, 14 were stable plaque and 40 were unstable plaques. The thickness and stenosis rate had no significant difference between stable group and unstable group (both P>0.05). The mean value of SWV and the ratio of typeⅠ/typeⅢ collagen fiber in stable plaques were higher than those in the unstable plaques (both P<0.05). Based on ROC analysis, a cut-off value of SWE of 3.725 m/s (AUC=0.936) showed a sensitivity of 92.9%, a specificity of 80.0% and an accuracy of 83.3% for predicting stable plaques (95% CI 0.818-0.982, P<0.05). The value of SWVs was closely correlated to the ratio of typeⅠ/typeⅢ collagen fiber in plaques(r=0.882, P<0.05). Conclusions SWV of the carotid atherosclerotic plaque can be used to reflect the ratio of the typeⅠ/typeⅢ collagen fiber in the plaques, and to evaluate the stability of plaque. Key words: Ultrasonography; Plaque, atherosclerotic; Virtual touch tissue imaging quantification; Collagen fibers

Diagnostic Value of Virtual Touch Tissue Imaging Quantification for Evaluating Median Nerve Stiffness in Carpal Tunnel Syndrome.

To measure the shear wave velocity (SWV) of the median nerve by Virtual Touch tissue imaging quantification (VTIQ; Siemens AG, Erlangen, Germany) through the beginning of the carpal tunnel and to determine whether VTIQ could be used to diagnose carpal tunnel syndrome. This study recruited 49 consecutive patients (72 wrists) with a definitive diagnosis of carpal tunnel syndrome and 23 healthy volunteers (46 wrists). We measured the median nerve diameter and cross-sectional area by 2-dimensional sonography and the SWV by VTIQ. The interobserver variability was analyzed, and diagnostic values were evaluated by drawing a receiver operating characteristic curve. The median nerve SWV was significantly higher in the carpal tunnel syndrome group (3.857 m/s) than the control group (2.542 m/s; P < .05). A 3.0-m/s SWV cutoff value revealed sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 83.3%, 91.3%, 93.8%, 77.8%, and 86.4%, respectively. The interobserver agreement was excellent for the SWV measurements. The median nerve SWV at the carpal tunnel inlet is significantly higher in patients with carpal tunnel syndrome, for whom VTIQ appears to be a highly reproducible diagnostic technique.

Combining Virtual Touch Tissue Imaging and BI-RADS May Improve Solid Breast Lesion Evaluation

Background: Ultrasound elastography (UE) is a novel imaging method. The purpose of this study was to determine the utility of Virtual Touch tissue imaging in the evaluation of solid breast lesions. Patients and Methods: 209 breast solid lesions in 192 patients that had been evaluated using ultrasound (US) and UE were reviewed and analyzed. Results: The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for UE, US, and US plus UE in the differentiation of malignant from benign breast lesions were 80.8, 75.6, 77.9, 73.1, and 82.8% for UE, 87.2, 86.1, 86.6, 83.7, and 89.2% for US, and 92.5, 86.9, 89.5, 85.3, and 93.4% for US plus UE. There were significant differences between UE and US plus UE (all p < 0.05). Except for accuracy, there were no significant differences between UE and US or US and US plus UE (all p > 0.05). The area under the curve obtained from the ROC curve for UE, US, and US plus UE in differentiating malignant from benign lesions was 0.845, 0.884, and 0.922, respectively. Conclusion: The UE scoring system is not superior to BI-RADS in the sonographic evaluation of solid breast lesions. Combined use may improve the performance.

Comparison of Virtual Touch Tissue Imaging & Quantification (VTIQ) and Virtual Touch Tissue Quantification (VTQ) for diagnosis ofthyroid nodules.

The aim of this study was to compare the diagnostic performance of Virtual Touch Tissue Imaging & Quantification (VTIQ) and Virtual Touch Tissue Quantification (VTQ) in differentiating benign from malignant thyroid nodules (TNs). In this study 107 TNs in 107 patients were enrolled and analyzed. All of them were detected by conventional ultrasound (US) and confirmed by fine-needle aspiration (FNA) biopsy or surgery. VTIQ and VTQ examinations were performed on each nodule. Thereafter the median and mean of shear wave speed (SWS) values in lesions on VTIQ and VTQ were computed (SWS-median and SWS-mean). With cytological results of FNA and histological results adopted as the reference standard, area under the receiver operating characteristic (AUROC) curve analysis was performed to evaluate the diagnostic efficiency of VTIQ and VTQ in differentiation of TNs. Among the 107 lesions, 19 were papillary thyroid carcinomas (PTCs), 1 was medullary thyroid carcinoma (MTC) and 87 were benign. In total lesions, AUROC-median in VTIQ was significantly higher than that in VTQ (0.851 vs.0.759; p < 0.05). VTIQ and VTQ were equivalent in diagnosing TNs when using SWS-mean, whereas VTIQ showed better performance in comparison with VTQ when using SWS-median.

Shear wave elastography of the testes inahealthy study collective - Differences instandard values between ARFI andVTIQtechniques.

Shear wave elastography (SWE) is a recent technique in the assessment of tissue elasticity. Different elastography techniques have been described over the years.Acoustic Radiation Force Impulse Imaging (ARFI) uses mechanical excitation of tissue to create detectable shear waves, a higher shear wave velocity being associated with an increased tissue stiffness.The Virtual Touch Tissue Imaging Quantification (VTIQ) method uses a mechanical push pulse as well, additionally creating a colour-coded map, in which tissue stiffness can be measured within a stored map on the ultrasound device after measurement.ARFI has been used in determining standard values in testes of a healthy study collective, VTIQ has already been used in the evaluation of unclear scrotal masses.Both techniques allow an operator-independent examination without application of mechanical pressure. The aim of this study was to determine whether there is a statistically significant difference between shear wave velocity values of both techniques in a healthy collective. Twenty patients without known testicular pathology underwent standard B-mode sonography and additional shear wave elastography in the ARFI mode as well as the VTIQ technique of both testes using the Siemens Acuson S2000™ and S3000™ ultrasound devices (Siemens HealthCare, Erlangen, Germany).Measurements of shear wave velocity were performed in the upper pole, the central portion and the lower pole separately for each testis. Values were described in m/s.Statistical evaluation was performed using paired t-test analysis. We measured a mean shear wave velocity of 0.81 m/s using ARFI and 1.07 m/s with VTIQ.Shear wave velocities determined by VTIQ were all significantly higher than values gained in the ARFI mode. (p < 0.001 to p = 0.007). Values were between 0.22 and 0.29 m/s higher, when the examination was performed using VTIQ. ARFI and VTIQ elastography modes both proved to be feasible techniques in the assessment of testicular tissue elasticity. Consideration of higher values for VTIQ is important, when different elastography measurement results are compared, especially for the application of devices in a clinical setting, e.g. in the work-up of scrotal masses.A calculable factor for a comparison between both devices is desirable, but to be further assessed in largerstudies.