Virtual Touch Quantification Research Articles

Doppler ultrasonography devices, including elastography, allow for accurate diagnosis of severe liver fibrosis

ObjectivesAdvanced chronic liver disease is frequent yet largely underdiagnosed. Doppler-US is a common examination and we recently identified three simple Doppler-US signs associated with severe liver fibrosis. Recent Doppler-US devices include elastography modules, allowing for liver stiffness measurement (LSM). Our aim was to assess whether the use of elastography following positive simple Doppler-US signs improves the detection of severe liver fibrosis in a single Doppler-US examination. Methods514 patients with chronic liver disease who consecutively underwent percutaneous liver biopsy were included in the study. All patients had a Doppler-US examination and LSM with Virtual Touch Quantification (VTQ) on the same day as a liver biopsy. A subset of 326 patients also had LSM with 2D shear wave elastography (SSI). Severe fibrosis was defined as Metavir F ≥ 3 on liver biopsy. ResultsMultivariate analysis confirmed our three simple Doppler-US signs (liver surface irregularity, splenomegaly ≥110 mm, and demodulation of hepatic veins) as independently associated with severe fibrosis. The presence of at least one of these three signs showed 85.6% sensitivity and 36.1% specificity for the diagnosis of severe liver fibrosis. Using VTQ (≥1.59 m/s) where there was a positive Doppler-US sign increased the specificity to 80.8%, at the cost of a decrease in sensitivity (73.7%). Similar results were obtained with SSI (≥9.5 kPa), with 73.3% specificity and 81.5% sensitivity. ConclusionElastography improves the accuracy of Doppler-US in the detection of severe fibrosis. This two-step procedure will help radiologists to accurately identify patients who need to be referred to specialist hepatologists during routine Doppler-US examinations.

Diagnostic value of acustic radiation force impulse imaging in the assessment of salivary gland involvement in primary Sjögren's sydrome.

The aim of this study is to investigate the diagnostic value of Acoustic Radiation Force Impulse (ARFI) imagingin the assessment of salivary gland involvement in primary Sjögren's syndrome (pSS). Twenty fivepatients with pSS and 25 healthy volunteers were included. First, echostructures and the thickness of the submandibular andparotid glands were evaluated by B-mode ultrasonography. Then, ARFI imaging with Virtual Touch Quantification® wasperformed. Ten independent shear wave velocity measurements were taken from each gland. Finally, the mean shear wavevelocity (SWV) values were calculated, and used for further analysis. The mean SWV values of parotid and submandibularglands were significantly higher in the pSS patients than in the healthy control group (p<0.001). The cut-off of SWVvalues were calculated to be 1.98 m/s for submandibular glands, and 1.93 m/s for parotid glands. In pSS patients, the meanSWV values of parotid glands were higher than those of the submandibular glands (p<0.001) and no statistically significantrelationships between symptom duration or the degree of xerostomia and mean SWV values of parotid and submandibularglands were found (all p>0.005). Our findings indicate that ARFI imaging may provide a non-invasive, simpleand fast means of assessment of glandular impairment as an alternative test when other salivary gland tests are inconclusive orcannot be performed. ARFI may be a valuable adjunct for the clinical diagnosis of pSS.

P2812Long-term prognostic significance of liver stiffness non-invasively measured by the virtual touch quantification in patients with acute decompensated heart failure

P2812Long-term prognostic significance of liver stiffness non-invasively measured by the virtual touch quantification in patients with acute decompensated heart failure

P3734Clinical value of a non-invasive measurement of increased liver stiffness by using virtual touch quantification for predicting elevated right atrial pressure in heart failure patients

P3734Clinical value of a non-invasive measurement of increased liver stiffness by using virtual touch quantification for predicting elevated right atrial pressure in heart failure patients

Does acoustic radiation force elastography improve the diagnostic capability of ultrasound in the preoperative characterization of masses of the parotid gland?

Ultrasound is the method of choice for preoperative evaluation of tumours of the parotid glands. However, existing methods do not allow for clear differentiation between the most common benign tumours and malignant tumours. The aim of our study was to evaluate if acoustic radiation force, Virtual Touch Quantification (VTQ) elastography helps to improve the preoperative evaluation of parotid masses. We investigated the parenchyma of 102 parotid glands, 14 lymph nodes of healthy volunteers and 51 tumours of the parotid gland via ultrasound, colour Doppler ultrasound and VTQ. The results were matched with histopathology and analyzed. The perfusion in pleomorphic adenoma, the most frequent benign tumour of the parotid gland, was significantly lower in comparison to malignant tumours. All tumours showed statistically significant higher perfusion in comparison to the parenchyma or the lymph nodes of the gland. Shear wave velocity of the user-defined region of interest was statistically significant more frequently an overflow value higher than 8.5 m/s in total tumours in comparison to parenchyma or lymph nodes. The different tumour types presented no significant difference in the shear wave velocity. VTQ in combination with classical ultrasound examination provides additional data useful in distinguishing between benign and malignant tumours and thus shows promise for integration into preexisting ultrasound protocols. However, despite the improvement, clear differentiation of tumours is still not possible and further investigation is recommended.

Criteria to Determine Reliability of Noninvasive Assessment of Liver Fibrosis With Virtual Touch Quantification

Virtual Touch Quantification (VTQ) evaluates liver fibrosis in patients with chronic liver diseases by measuring shear wave speed in the liver. We aimed to determine the reliability criteria of VTQ examination. We performed a prospective study of 1094 patients with chronic liver disease from November 2009 through October 2016 at Angers University Hospital, and between April 2010 and May 2015 at Bordeaux University Hospital, in France. All patients underwent liver biopsy analysis (reference standard), and VTQ examination was made by experienced operators on the same day, or no more than 3 months before or afterward. Advanced liver fibrosis was defined as fibrosis stage F ≥ 3 according to the scoring system of the Nonalcoholic Steatohepatitis Clinical Research Network, or fibrosis stage F ≥ 2 according to the Metavir scoring system. The diagnostic accuracy of VTQ in detection of advanced fibrosis or cirrhosis was assessed using the area under the receiver operating characteristic (AUROC) and the rate of correctly classified patients. Reliability criteria were defined from the intrinsic characteristics of VTQ examination, which were shown to influence the diagnostic accuracy. VTQ identified patients with advanced fibrosis with an AUROC of 0.773 ± 0.014 and correctly classified 72.0% of patients using a diagnostic cut-off value of 1.37 m/s. VTQ identified patients with cirrhosis with an AUROC value of 0.839 ± 0.014 and correctly classified 78.4% of patients using a cut-off value of 1.87 m/s. The reliability of VTQ decreased with an increasing ratio of interquartile range/median (IQR/M) in patients with intermediate-high VTQ results. We defined 3 reliability categories for VTQ: unreliable (IQR/M ≥0.35 with VTQ result ≥1.37 m/s), reliable (IQR/M ≥0.35 with VTQ result <1.37 m/s or IQR/M 0.15-0.34), and very reliable (IQR/M <0.15). For advanced fibrosis, VTQ correctly classified 57.8% of patients in the unreliable group, 73.7% of patients in the reliable group, and 80.9% of patients in the very reliable group (P < .001); for cirrhosis, these values were 50.0%, 83.4%, and 92.6%, respectively (P < .001). Of the VTQ examinations made, 21.4% were unreliable, 55.0% were reliable, and 23.6% were very reliable. The skin-liver capsule distance was independently associated with an unreliable VTQ examination, which occurred in 52.7% of patients with a distance of 30 mm or more. In a study to determine the reliability of VTQ findings, compared with results from biopsy analysis, we assigned VTQ examinations to 3 categories (unreliable, reliable, and very reliable). VTQ examinations with IQR/M ≥0.35 and ≥1.37 m/s had very low diagnostic accuracy. Our reliability criteria for liver fibrosis assessment with VTQ will help physicians to accurately evaluate the severity of chronic liver diseases and monitor their progression.

Correlation of Point Shear Wave Velocity and Kidney Function in Chronic Kidney Disease.

Point shear wave elastography is a quantitative ultrasound-based imaging method used in the assessment of renal disease. Among point shear wave elastographic options, 2 techniques have been studied considerably: Virtual Touch quantification (VTQ; Siemens AG, Erlangen, Germany) and ElastPQ (EPQ; Philips Healthcare, Bothell, WA). Both rely on the tissue response to an acoustic beam generated by the ultrasound transducer. The data on renal VTQ are more extensive, whereas EPQ has been used less thus far in the assessment of the kidneys. This study aimed to evaluate the performance of EPQ in the kidney and compare it with VTQ. We studied 124 participants using EPQ: 22 with no renal disease and 102 with chronic kidney disease (CKD). Ninety-one were studied with both the EPQ and VTQ methods. We obtained 5 valid measurements in each kidney, expressed in meters per second. The mean kidney stiffness measurements ± SD obtained with EPQ in the healthy control group were as follows: right kidney, 1.23 ± 0.33 m/s; and left kidney, 1.26 ± 0.32 m/s (P = .6). In the patients with CKD (all stages), the mean kidney stiffness measurements obtained were significantly lower: right kidney, 1.09 ± 0.39 m/s; and left kidney, 1.04 ± 0.38 m/s (P = .4). We observed that, similar to VTQ, EPQ values decreased with CKD progression, based on analysis of variance results using different CKD stages. From a receiver operating characteristic curve analysis, the cutoff value for an estimated glomerular filtration rate of less than 45 mL/min was 1.24 m/s, and the value for an estimated glomerular filtration rate of less than 30 mL/min was 1.07 m/s. When using EPQ, the kidney shear wave velocity is decreased in patients with CKD, an observation similar to that obtained by using the VTQ method.

Use of ARFI elastography in the prediction of placental invasion anomaly via a new Virtual Touch Quantification Technique

We aimed to evaluate the efficiency of placental elasticity in predicting a placental invasion anomaly with the Virtual Touch Quantification (VTQ) technique. Pregnant women in the third trimester with suspected placental invasion anomaly were enrolled into the research (n = 58). The placenta was evaluated and divided into three equal parts as foetal edge (inner 1/3 of placenta), maternal edge (outer 1/3 of placenta) and the central part (central 1/3 of placenta). Shear wave velocity (SWV) measurements were used in the elastographic evaluation of placentas by VTQ. We performed the measurements at the different regions of placenta for sampling the variety areas of the placenta. Acoustic Radiation Force Impulse (ARFI) Elastography scores were significantly higher in the group in which an invasion was detected during the surgery of patients with preoperative placental invasion suspicion. A significant difference in the measurements of the inner, central and outer third of the placenta between the groups was found (p < .001). In this study, we have shown higher SWV scores of placental measurements of the patients with preoperative suspected anomalies and an invasion detected during their surgery. These findings may reflect an event at the tissue elasticity level and we hope that the use of the VTQ technique may contribute to an early prediction of placental invasions before surgery in the future via new research.Impact statementWhat is already known on this subject? Placenta invasion anomalies (PIA’s) are characterized by haemorrhages which can threat the mother’s life. Placental invasion anomalies are among the most important causes of maternal mortality and morbidity. Early diagnosis is very important condition in reducing the mortality and morbidity. Gray scale ultrasonography (US) is mostly used in early diagnosis of PIA’s. Acoustic radiation force impulse elastography (ARFI) is a new elastographic ultrasonography technic. We aimed to evaluate a new method in the early diagnosis of PIA’s using ARFI technique. There is no study in the diagnosis of PIA’s by ARFI in the literature to our knowledge. We think that this original study will contribute to the literature.What do the results of this study add? We showed the accuracy of ARFI in determination of PIA’s. ARFI scores were significantly higher in the group in which invasion was detected during surgery of patients with preoperative placental invasion suspicion.What are the implications are of these findings for clinical practice and/or further research? Our findings may reflect an event at the tissue elasticity level and we hope that the use of VTQ technique may contribute to early predict of placental invasions before surgery in the future via new researches. Early diagnosis of placental invasion anomalies may reduce mortality and morbidity.

Is Acoustic Radiation Force Impulse (ARFI) Ultrasound Elastography Valuable in the Assessment of Cervical Lymphadenopathy?

Cervical lymphadenopathy frequently poses a diagnostic challenge as neither clinical nor imaging assessment can reliably differentiate between benign and malignant lymphadenopathy. Non-invasive differentiation between the two may help to reduce the number of FNAC or biopsy. The purpose of this study was to evaluate whether the new ARFI technique (Virtual Touch Quantification), in conjunction with gray scale sonography and Doppler, can help in the characterization and differentiation of benign from malignant cervical lymphadenopathy. Fifty adult patients with cervical lymphadenopathy were included in the study and sonoelastography was done. Sonoelastographic findings were compared to the gold standard histopathology or cytopathology. ARFI measurements in benign and malignant enlarged lymph nodes were compared using the Student t test and ROC curve was used to arrive at the Youden index, sensitivity, specificity, PPV, NPV and diagnostic accuracy. Sonographic patterns indicative of malignancy includes heterogenous echopattern, short axis/long axis ratio > 0.5, absent echogenic fatty hilum and mixed vascular pattern. Sensitivity, specificity, PPV, NPV and accuracy in differentiation between the benign and malignant lymph nodes using ARFI elastography was 79.17, 100, 100, 83.9 and 89.9% respectively. ROC curve analysis of SWVs for differentiation between the malignant and benign lymph nodes gave a cut-off value of 2.8m/s with an area under curve of 0.892. ARFI imaging technique quantifies the tissue stiffness of the cervical lymph nodes non-invasively and aids in characterisation and differentiation of benign from malignant cervical lymphadenopathy in conjunction with conventional sonography.

Is there a correlation between kidney shear wave velocity measured with VTQ and histological parameters in patients with chronic glomerulonephritis? A pilot study.

To analyze the relationship between shear wave velocity in the kidney measured by point shear wave elastographyusing Virtual Touch Quantification (VTQ) (Siemens Acuson S2000) and histological parameters obtained from renal biopsies,in patients with chronic glomerulonephritis (CGN). The study group included 20 patients (meanage 47.95±13.59 years) with different types of CGN, that had underwent renal biopsy and 57 normal controls (mean age38.07±17.32 years). In all patients, five valid stiffness measurements were obtained in each kidney, with the patient in lateraldecubitus. Regarding the histological results, we assessed the presence or absence of glomerulosclerosis, interstitial fibrosis,and arteriolo-hyalinosis. In patients with CGN we obtained the following mean values of VTQ values: right kidney:2.12±0.81 m/s, left kidney 1.65±0.54 m/s, while in the normal controls significantly higher VTQ values were obtained: rightkidney 2.69±0.72 m/s (p=0.004), left kidney 2.48±0.73 m/s (p<0.0001). In patients with CGN no statistically significant correlationsbetween VTQ values and eGFR (r=0.37, p=0.12) or proteinuria (r=0.2, p=0.37) were found. We found significantlylower VTQ values in patients with interstitial fibrosis (1.46 vs. 1.99 m/s, p<0.05) and also in patients with arteriolo-hyalinosis(1.55 vs. 2.47 m/s, p<0.05). Our pilot study shows that shear wave velocity values in patients with CGN are significantlylower compared to normal controls, and there is a tendency to decrease with the decrease of eGFR, with the presenceof interstitial fibrosis and of arteriolo-hyalinosis.

Usefulness of virtual touch quantification for staging liver fibrosis in patients with hepatitis C, and factors affecting liver stiffness measurement failure compared with liver biopsy.

The assessment of liver fibrosis in patients with hepatitis C is important to predict carcinogenesis. In this study, we evaluated the usefulness of virtual touch quantification (VTQ) for staging liver fibrosis, and investigated factors causing discrepancies between the estimated fibrosis stage using VTQ and the pathological fibrosis stage. Patients with hepatitis C (n = 302) were assessed using VTQ and underwent pathological liver investigation within 1 week before and after VTQ. A receiver operator characteristic (ROC) curve was obtained for VTQ, fibrosis-4 (FIB-4) index, and aspartate aminotransferase-to-platelet ratio index (APRI), and each area under the ROC curve (AUROC) was compared to predict fibrosis stage. We used univariate and multivariate analyses to investigate the factors related to the discrepancy between the estimated fibrosis stage using VTQ and the pathological fibrosis stage. At any stage, VTQ was the most accurate for staging liver fibrosis. The VTQ cut-off values were 1.33 m/s (AUROC = 0.822) for ≥F2, 1.51 m/s (AUROC = 0.836) for ≥F3, and 1.92 m/s (AUROC = 0.890) for F4. Skin liver capsule distance (SCD) was the most relevant factor for the discrepancy between the estimated fibrosis stage using VTQ and the pathological fibrosis stage. The SCD cut-off value was 17.5 mm. Virtual touch quantification is a non-invasive, simple method that is more accurate for staging liver fibrosis than the FIB-4 index and APRI. However, when the SCD is longer than 17.5 mm, there may be measurement failures.

Impact of Virtual Touch Quantification in Acoustic Radiation Force Impulse for Skeletal Muscle Mass Loss in Chronic Liver Diseases.

Background and aims: We sought to clarify the relationship between virtual touch quantification (VTQ) in acoustic radiation force impulse and skeletal muscle mass as assessed by bio-electronic impedance analysis in patients with chronic liver diseases (CLDs, n = 468, 222 males and 246 females, median age = 62 years). Patients and methods: Decreased skeletal muscle index (D-SMI) was defined as skeletal muscle index (SMI) <7.0 kg/m2 for males and as SMI <5.7 kg/m2 for females, according to the recommendations in current Japanese guidelines. We examined the correlation between SMI and VTQ levels and investigated factors linked to D-SMI in the univariate and multivariate analyses. The area under the receiver operating curve (AUROC) for the presence of D-SMI was also calculated. Results: In patients with D-SMI, the median VTQ level was 1.64 meters/second (m/s) (range, 0.93–4.32 m/s), while in patients without D-SMI, the median VTQ level was 1.11 m/s (range, 0.67–4.09 m/s) (p < 0.0001). In the multivariate analysis, higher VTQ was found to be an independent predictor linked to the presence of D-SMI (p < 0.0001). In receiver operating characteristic analysis, body mass index had the highest AUROC (0.805), followed by age (0.721) and VTQ (0.706). Conclusion: VTQ levels can be useful for predicting D-SMI in patients with CLDs.

Role of Point Shear Wave Elastography in the Determination of the Severity of Fibrosis in Pediatric Liver Diseases With Pathologic Correlations.

Our aims in this study were as follows: (1) to determine the cutoff value that can distinguish between advanced liver fibrosis and normal liver tissue for two different elastographic techniques; (2) to determine the cutoff value that can distinguish mild liver fibrosis from normal liver tissue for the techniques; and (3) to assess tissue stiffness in nonalcoholic fatty liver disease (NAFLD). Seventy-five patients assessed for liver biopsy on the same day were evaluated by point shear wave elastography. Thirty-one healthy children and 11 children with NAFLD were also evaluated. A 9L4 transducer with Virtual Touch quantification (VTQ) and Virtual Touch imaging and quantification (VTIQ) modes (Siemens Medical Solutions, Mountain View, CA) was used for quantification. The shear wave speed of the patients with NAFLD was higher than that of the control group. The only predictive factor for VTQ and VTIQ was the histologic fibrosis score (model-adjusted R2 = 0.56 for VTQ and 0.75 for VTIQ). Shear wave speed cutoffs were 1.67 m/s for VTQ and 1.56 m/s for VTIQ in detecting fibrosis or inflammation and 2.09 m/s for VTQ and 2.17 m/s for VTIQ in discriminating children with low and high histologic liver fibrosis scores. The VTQ and VTIQ values reveal high-grade histopathologic fibrosis and have high success rates when distinguishing high- from low-grade fibrosis. However, they have limited success rates when differentiating low-grade fibrosis from normal liver tissue.

Acoustic Radiation Force Impulse Imaging in Benign and Malignant Breast Lesions.

BackgroundElastography is a promising way to assess tissue differences regarding stiffness or elasticity, which has been historically assessed manually by palpation. Combined with conventional imaging modalities, shear wave elastography can potentially evaluate the stiffness of a breast lesion and consequently help detect malignant breast tumor from benign ones. The aim of this study was to evaluate the diagnostic role of shear wave elastography in breast lesions in the Indian population.Material and methodsFifty patients presenting with breast lesions were included in the study. All the patients were subjected to B-mode ultrasound and elastography using shear wave with Virtual Touch Imaging (VTITM) (Siemens Medical Solutions USA, Inc., PA, USA) and Virtual Touch Quantification (VTQTM) (Siemens Medical Solutions USA, Inc., PA, USA) and the obtained data was analyzed using an appropriate statistical test (independent samples t-test).ResultsIn our study group of 50 patients, 34 were benign and 16 were malignant. VTITM showed a sensitivity of 97% and a specificity of 93% with a positive predictive value (PPV) of 97% for benign lesions. VTITM showed a sensitivity of 87.5 % and a specificity of 100% with a PPV of 100% for malignant lesions. VTQTM showed a sensitivity of 71.4% and a specificity of 100% with a PPV of 100% for benign lesions. VTQTM showed a sensitivity of 100% and a specificity of 100% with a PPV of 76.6% for malignant lesions.ConclusionsVTITM was more reliable as a diagnostic tool compared to VTQTM in benign lesions and both are equally reliable in identifying malignant lesions. Acoustic radiation force impulse (ARFI) plays a significant role as an adjuvant diagnostic tool to B-mode imaging for assessing breast lesions.

Can ARFI elastography be used to differentiate parathyroid from thyroid lesions?

To assess if elasticity score (ES) and shear wave velocity (SWV) measurement obtained using ARFI elastography can differentiate between parathyroid lesions and thyroid nodules. ARFI elastography was performed on patients with primary hyperparathyroidism or solid thyroid nodules who were being considered for surgery using virtual touch quantification and virtual touch imaging (VTI) software. Only patients with surgical histopathology (47 parathyroid lesions, 38 benign thyroid nodules and 55 malignant thyroid nodules) were included for final analysis. SWV and ES of the parathyroid and thyroid nodules were compared and their ability to differentiate between parathyroid and thyroid was analyzed using receiver operating characteristic curve analysis. There were 39 solitary adenomas, 2 double adenomas and 4 parathyroid hyperplasias with mean size of 19.6±9.7mm in 44 patients (21 male, 23 females) with primary hyperparathyroidism. The mean SWV of the parathyroid lesion (1.6±0.78m/s) was significantly different from benign (2.11±0.8m/s) and malignant (4.3±2.71m/s) thyroid nodules, p<0.05; so was the ES, Chi square=51.6, p<0.001. The majority of parathyroid lesions (n=37, 78.7%) had ES of 2 with speckled (n=42, 89.3%) appearance, and none showed ES of 4. The diagnostic performance of speckled appearance on VTI, elasticity score and SWV measurements was 0.901, 0.724 and 0.797, respectively, to differentiate between parathyroid and thyroid lesions. Parathyroid lesions are softer than thyroid nodules. A shear wave velocity of 1.72m/s can differentiate between parathyroid lesions and thyroid nodules.

Reproducibility of 2‐Dimensional Shear Wave Elastography Assessment of the Liver: A Direct Comparison With Point Shear Wave Elastography in Healthy Volunteers

Two-dimensional shear wave elastography (2D-SWE) imaging for the noninvasive assessment of tissue stiffness was assessed for reproducibility in healthy volunteers in quantifying liver elasticity, compared with an established point shear wave elastography (p-SWE) technique also known as virtual touch quantification (VTQ) (SIEMENS). Eleven healthy volunteers were examined by four experienced operators on two occasions, separated by two weeks (sessions A and B). Ten 2D-SWE using LOGIQ E9 and p-SWE measurements using VTQ (in meters per second) were consecutively taken from deep portions of liver segments 5 or 6 away from vascular structures, using standard techniques. Inter- and intra-observer agreement was assessed by intraclass coefficient (ICC). A total of 880 2D-SWE and p-SWE velocities were recorded. Mean values from the four operators ranged between 1.188 and 1.196 m/s for 2D-SWE and 1.170 to 1.207 m/s for p-SWE. Interobserver reproducibility was good for both sessions with ICCs of 0.88 and 0.93 (2D-SWE) and 0.87 and 0.93 (p-SWE). The overall intra-operator reproducibility between sessions A and B was good for both p-SWE and 2D-SWE with ICC of 0.87 and 0.83, respectively. For inter- and intra-observer variability, the ICC was more than or equal to 0.71, indicating that the results were reliable. There was a strong and significant correlation between the 2D-SWE and p-SWE measurements (r = 0.87, P = .0006), but their velocities did not agree equally across different velocities. Two-dimensional SWE using LOGIQ E9 is a reliable and reproducible method for measuring elasticity in healthy volunteers and has a similar degree of reliability as p-SWE using VTQ, but absolute measurements from the two techniques should not be used interchangeably.

Evaluation of the Usefulness of Quantitative Shear Wave Elastography for Differentiating Benign and Malignant Salivary Gland Tumors

Elastography is a technique for assessing hardness and includes both qualitative and quantitative approaches. The utility of quantitative shear wave elastography (SWE) for the differential diagnosis of salivary gland tumors is unclear. Hence, we investigated this by comparing the results of Virtual Touch Quantification (VTQ), a form of quantitative SWE, of different salivary gland tumors. Patients with salivary gland tumors who underwent ultrasonography in our department between July 2014 and April 2017 and had a cytological or histological diagnosis were included. The ultrasonic diagnosis device used was the ACUSON S2000 (Siemens Medical Solutions USA, Inc. Malvern, PA, USA). A solid part of the tumor was selected for measurement with VTQ. For VTQ, the shear wave speed was calculated within a 5-mm square ROI; instances where calculation was impossible are indicated with x.xx. Thus, the feasibility of VTQ measurement and the measured value (m/s) of each tumor were compared. Seventy-one cases were benign tumors (45 Warthin's tumors and 26 pleomorphic adenomas) and 15 cases were malignant tumors. The VTQ measurability ratio and measured value medians were 70.4% and 2.44, respectively, for the benign tumors (82.2% and 2.35 for Warthin's tumor, 50% and 2.76 for pleomorphic adenoma) and 13.3% and 1.58, respectively, for the malignant tumors. VTQ successfully measured most cases of Warthin's tumors, but failed to measure malignant tumors and pleomorphic adenomas. Because of this low rate, the utility of the measured values could not be determined. However, when a measurement was possible, this had the potential to aid in the prediction of benign tumors, especially Warthin's tumor, which can be followed-up with observation.

Prospective Validation of Intra- and Interobserver Reproducibility of a New Point Shear Wave Elastographic Technique for Assessing Liver Stiffness in Patients with Chronic Liver Disease.

ObjectiveTo assess intra- and inter-observer reproducibility of a new point shear wave elastography technique (pSWE, S-Shearwave, Samsung Medison) and compare its accuracy in assessing liver stiffness (LS) with an established pSWE technique (Virtual Touch Quantification, VTQ).Materials and MethodsThirty-three patients were enrolled in this Institutional Review Board-approved prospective study. LS values were measured by VTQ on an Acuson S2000 system (Siemens Healthineer) and S-Shearwave on an RS-80A (Samsung Medison) in the same session, followed by two further S-Shearwave sessions for inter- and intra-observer variation at 8-hour intervals. The technical success rate (SR) and reliability of the measurements of both pSWE techniques were compared. The intra- and inter-observer reproducibility of S-Shearwave was determined by intraclass correlation coefficients (ICCs). LS values were measured by both methods of pSWE. The diagnostic performance in severe fibrosis (F ≥ 3) and cirrhosis (F = 4) was evaluated using the receiver operating characteristics curve analysis and the Obuchowski measure with the LS values of transient elastography as the referenced standard.ResultsThe VTQ (100%, 33/33) and S-Shearwave (96.9%, 32/33) techniques did not display a significant difference in technical SR (p = 0.63) or reliability of LS measurements (96.9%, 32/33; 93.9%, 30/32, respectively, p = 0.61). The inter- and intra-observer agreement for LS measurements using the S-Shearwave technique was excellent (ICC = 0.98 and 0.99, respectively). The mean LS values of both pSWE techniques were not significantly different and exhibited a good correlation (r = 0.78). To detect F ≥ 3 and F = 4, VTQ and S-Shearwave showed comparable diagnostic accuracy as indicated by the following outcomes: areas under receiver operating characteristics curve (AUROC) = 0.87 (95% confidence intervals [CI] 0.70–0.96), 0.89 for VTQ (95% CI 0.74–0.97), respectively; and AUROC = 0.84 (95% CI 0.67–0.94), 0.94 (95% CI 0.80–0.99) for S-Shearwave (p > 0.48), respectively. The Obuchowski measures were similarly high for S-Shearwave and VTQ (0.94 vs. 0.95).ConclusionS-Shearwave shows excellent inter- and intra-observer agreement and diagnostic effectiveness comparable to VTQ in detecting LS.

Utility of virtual touch quantification in the diagnosis of pancreatic ductal adenocarcinoma

This study aimed to compare the tissue stiffness of pancreatic ductal adenocarcinoma (PDAC) with that of pancreatic parenchyma using virtual touch quantification (VTQ). SWV was measured in 34 PDAC lesions and in pancreatic parenchyma of both controls and patients.SWVs in PDAC lesions were significantly higher than in pancreatic parenchyma in both healthy controls and in patients with PDAC. The area under the ROC for diagnosis of PDAC was 0.94 for pancreatic parenchyma in healthy controls, and 0.85 for pancreatic parenchyma in patients with PDAC.VTQ can provide a useful and additional information for diagnosis of PDAC.

Virtual Touch Quantification of the Salivary Glands for Diagnosis of Primary Sjögren Syndrome.

To investigate the value of salivary gland stiffness measured by Virtual Touch quantification (VTQ; Siemens Medical Solutions, Erlangen, Germany) for assessment of primary Sjögren syndrome. Fifty-four patients with primary Sjögren syndrome, 35 patients without primary Sjögren syndrome (patients with dry mouth and dry eye symptoms), and 52 healthy control volunteers were included in this study. Patients with primary Sjögren syndrome were classified as early or advanced stage by labial gland biopsies. All participants underwent B-mode sonography, on which the salivary glands (parotid and submandibular) were identified and VTQ measurements of shear wave velocity (SWV) were obtained. The diagnostic performance of SWV was evaluated by sensitivity and specificity at the optimum cutoff point and the area under the receiver operating characteristic curve. For submandibular glands, the mean SWV ± SD values were 2.25 ± 0.34 m/s in patients with early-stage primary Sjögren, 1.84 ± 0.20 m/s in patients without primary Sjögren syndrome, and 1.82 ± 0.27 m/s in healthy controls (P< .001). With cutoff values of 2.15 and 2.10 m/s to separate patients with early-stage primary Sjögren syndrome from those without Sjögren syndrome and healthy controls, the sensitivity and specificity were 77.1% and 85.4% and 79.2% and 83.9%, respectively. For parotid glands, the SWV values were 2.78 ± 0.82 m/s in patients with early-stage primary Sjögren syndrome, 1.93 ± 0.33 m/s, in patients without primary Sjögren syndrome, and 1.85 ± 0.31 m/s in healthy controls (P < .001). With cutoff values of 2.18 and 2.10 m/s to separate patients with early-stage primary Sjögren syndrome from those without Sjögren syndrome and healthy controls, the sensitivity and specificity were 89.3 % and 75.3% and 91.4% and 80.0%. The VTQ technique might be a useful noninvasive strategy for assessment of salivary glands in the early stage of primary Sjögren syndrome.