Virtual Touch Tissue Quantification of Acoustic Radiation Force Impulse: A New Ultrasound Elastic Imaging in the Diagnosis of Thyroid Nodules

Abstract

ObjectiveVirtual touch tissue quantification (VTQ) of acoustic radiation force impulse (ARFI) is a new quantitative technique to measure tissue stiffness. The study was aimed to assess the usefulness of VTQ in the diagnosis of thyroid nodules.Methods173 pathologically proven thyroid nodules in 142 patients were included and all were examined by conventional ultrasound (US), conventional elasticity imaging (EI) and VTQ of ARFI. The tissue stiffness for VTQ was expressed as shear wave velocity (SWV) (m/s). Receiver-operating characteristic curve (ROC) analyses were performed to assess the diagnostic performance. Intra- and inter-observer reproducibility of VTQ measurement was assessed.ResultsThe SWVs of benign and malignant thyroid nodules were 2.34±1.17 m/s (range: 0.61–9.00 m/s) and 4.82±2.53 m/s (range: 2.32–9.00 m/s) respectively (P<0.001). The mean SWV ratios between each nodule and the adjacent thyroid tissue were 1.19±0.67 (range: 0.31–6.87) for benign and 2.50±1.54 (range: 0.85–6.69) for malignant nodules (P<0.001). ROC analyses indicated that the area under the curve was 0.861 (95% CI : 0.804, 0.918) (P<0.001) for SWV and 0.831(95% CI : 0.761, 0.900)(P<0.001) for the SWV ratio. The cutoff points for the differential diagnosis were 2.87 m/s for SWV and 1.59 for SWV ratio. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for EI were 65.9%, 66.7%, 66.5%, 40.3%, and 85.1%, respectively, and were 63.6%–75%, 82.2%–88.4%, 80.3%–82.1%, 58.9%–65.1%, and 87.7%–90.5%, respectively, for VTQ. The diagnostic value of VTQ is the highest for nodules >20 mm and lowest for those ≤10 mm. The correlation coefficients were 0.904 for intraobserver measurement and 0.864 for interobserver measurement.ConclusionsVTQ of ARFI provides quantitative and reproducible information about the tissue stiffness, which is useful for the differentiation between benign and malignant thyroid nodules. The diagnostic performance of VTQ is higher than that of conventional EI.

Ultrasonographic United Stiffness Score System: Resolving the Discrepancy between Acoustic Radiation Force Impulse and Real-time Elastography in Evaluating the Thyroid Nodules Stiffness

“…In other words, both extremely hard and soft tissue can be shown as "X.XX m/s". In most previous study, the value of "X.XX m/s" is allocated to be 0 m/s or 9 m/s with 0 m/s corresponding cystic portion and 9 m/s corresponding solid portion [20]. Considering that 0 and 9 were the extreme values in Vs range, and frequent appearance would lead the Vs group to be skewness distribution, in present study, we excluded the thyroid which Vs displayed as "X.XX m/s", thus t test could be used to compare ARFI-measurements in benign thyroid nodules and malignant thyroid nodules.…”

“…Tissue within a "measuring box" (6 × 5 mm) is mechanically stimulated using short-duration (262 µs) acoustic pulses [8]. The stiffer (nonelastic) the tissue through which the wave passes, the greater the shear velocity is.…”

“…Tissue stiffness is another feature that may reflect the nature of the thyroid nodule, neoplastic diseases can alter tissue composition and structure, that may reflect the nature of the thyroid nodule, with the malignant nodule tends to be hard and the benign nodule be soft [8]. Elastography is a new sonographic technology that reflects tissue stiffness.…”

Evaluation of capability of ultrasound with elastometry and elastography for diagnosis of subclinical regional metastases of cancer of the oral mucosa

“…Для оценки возможности использовании эласто-метрии в целях диагностики субклинических метаста-зов был проведен статистический анализ полученных (27,3) Сокращения: pN0 и pN+ -соответственно отсутствие и наличие метастаза по данным гистологического исследования.…”

“…Кроме того, необходимы дополнительные исследова-ния для установления пороговых величин эластоме-трии, а также уточнение эластографических параме-тров диагностики субклинических метастазов. Пороговая величина для дифференциальной диагно-стики между непораженными и пораженными опухо-лью лимфатическими узлами, по данным различных исследований, колеблется в пределах 1,5-4,82 м / с [20,[24][25][26][27][28].…”