Evaluation Of Tissue Stiffness Research Articles

Q-Elastography in the Presurgical Diagnosis of Thyroid Nodules with Indeterminate Cytology

Quantitative ultrasound (US) elastography (Q-USE), able to evaluate tissue stiffness has been indicated as a new diagnostic tool to differentiate benign from malignant thyroid lesions. Aim of this prospective study, conducted at the Department of Surgical Sciences, of the “Sapienza” University of Rome, was to evaluate the diagnostic accuracy of Q-USE, compared with US parameters, in thyroid nodules with indeterminate cytology (Thy3).The case study included 140 nodules from 140 consecutive patients. Patient’s thyroid nodules were evaluated by Q-USE, measuring the strain ratio (SR) of stiffness between nodular and surrounding normal thyroid tissue, and conventional US parameters prior fine-needle aspiration cytology. Those with Thy3 diagnosis were included in the study. Forty of the nodules analyzed harbored a malignant lesion. Q-USE demonstrated that malignant nodules have a significant higher stiffness with respect to benign one and an optimun SR cut-off value of 2.05 was individuated following ROC analysis. Univariate analysis showed that hypoechogenicity, irregular margins and SR >2.05 associated with malignancy, with an accuracy of 67.2%, 81,0% and 89.8%, respectively. Data were unaffected by nodule size or thyroiditis. These findings were confirmed in multivariate analysis demonstrating a significant association of the SR and the irregular margins with thyroid nodule’s malignancy. In conclusion, we demonstrated the diagnostic utility of Q-USE in the differential diagnosis of thyroid nodules with indeterminate cytology that, if confirmed, could be of major clinical utility in patients’ presurgical selection.

Study of influential factors in evaluating tissue stiffness by virtual touch tissue quantification

Objective To investigate the influence of different depths and mediums on tissue stiffness measurement by virtual touch tissue quantification technology.Methods Four kinds of in vitro porcine tissue were recruited,three (fat,muscle and liver) were assigned as medium group and three (kidney,liver and muscle) as sample group.The shear wave velocity (Vs) of the samples was measured under different mediums and at different depths (2 cm,3 cm,4 cm and 5 cm),respectively.Results According to the depth of measurement,two groups of Vs were defined with one group at the depth of 2 cm and 3 cm while the other at 4 cm and 5 cm.The difference of Vs between the two groups was of statistical significance and with the increase of the depth Vs values decreased.Even at the same depth,the differences of Vs under different mediums were statistically significant.Conclusions Depths and mediums have great influence on evaluating elasticity measurements by virtual touch tissue quantification technology. Key words: Ultrasonography; Elasticity; Virtual touch tissue quantification

The role of ultrasound elastography in preoperative localization of parathyroid lesions: a new assisting method to preoperative parathyroid ultrasonography

After the definition of minimally invasive procedures, preoperative localization of parathyroid lesions is now crucial. False-positive results up to 30% were reported by B-mode grayscale ultrasonography (US) in localization of parathyroid lesions. Parathyroid adenomas are relatively stiff lesions. Ultrasound elastography (USE) can accurately evaluate tissue stiffness and might detect the stiff parathyroid lesions. The aim of this study is to demonstrate whether USE can detect the level of the stiffness and help the preoperative localization of parathyroid lesions during parathyroid ultrasonography examination. The patients who were candidates for parathyroidectomy were prospectively enrolled to this study and were evaluated by USE. Seventy-two patients with 93 parathyroid lesions underwent parathyroidectomy. Sixty-three patients including three multiple endocrine neoplasia type-1 patients had primary hyperparathyroidism, three patients with chronic renal disease (CRD) had tertiary hyperparathyroidism, three patients with CRD and two renal transplanted patients had persistent secondary hyperparathyroidism. One patient was excluded. While all parathyroid adenomas exhibited high levels of stiffness (score 3 and 4), 17 (63%) out of 27 parathyroid hyperplasia lesions were shown to have significantly higher elasticity. The evaluation of median strain ratios of parathyroid lesions revealed that parathyroid adenomas demonstrated significantly higher levels of stiffness than hyperplasias (P ≤ 0·001). This is the first study that evaluates the ultrasound elastographic features of parathyroid lesions. Parathyroid adenomas were shown to appear as stiff lesions, and half of the hyperplasias showed high elasticity. Parathyroid elastography is a novel technique to evaluate parathyroid lesions and might be a guide for surgeons to determine the type of operation to apply.

New Horizons in Doppler Ultrasound Technology: Relevance for Obstetrical Applications

Technologic advances and clinical research have been extending the scope of Doppler sonography and have resulted in the emergence of new diagnostic tools that show significant promise in clinical applications. This article aims to review some of these developments that are relevant for obstetrical practice. One of the major recent technical developments in ultrasound imaging is the ability to assess tissue deformation. This has led to several clinical applications including functional echocardiography that allows evaluation of myocardial function using Doppler and speckle tracking techniques, and sonoelastography, which is ultrasound evaluation of tissue stiffness. Another relevant innovation is power Doppler imaging of regional perfusion. With further critical investigations, these emerging techniques may evolve into useful clinical tools.

Evaluation of acoustic radiation force impulse elastography for fibrosis staging of chronic liver disease: a pilot study

Acoustic radiation force impulse (ARFI) is a new technology integrated into conventional B-mode ultrasonography. ARFI is used to evaluate tissue stiffness in several organs, but this method has not been applied for liver fibrosis. The aim of this study was to determine whether ARFI elastography is useful for the evaluation of liver fibrosis. This study enrolled 55 consecutive patients with chronic liver disease who underwent a liver biopsy for histological assessment of liver fibrosis by the Metavir scoring system. Liver stiffness of the 55 patients and 25 healthy volunteers was evaluated by ARFI elastography and was expressed as the shear wave velocity. Cut-off values were determined using receiver-operating characteristic (ROC) curves. Histological liver fibrosis was evaluated by Metavir scoring; F0: six cases, F1: 14 cases, F2: nine cases, F3: nine cases and F4: 17 cases. Liver stiffness determined by ARFI elastography was correlated with histological liver fibrosis (P<0.0001). The areas under the ROC curves were 0.94 (95% confidence intervals, 0.87-0.99) for F2-F4, 0.94 (0.88-0.99) for F3-F4 and 0.96 (0.91-1.01) for F4. The cut-off values of the shear wave velocity were as follows: >1.34 m/s for F2-F4 (sensitivity 91.4%, specificity 80%); >1.44 m/s for F3-F4 (sensitivity 96.2%, specificity 79.3%); and >1.80 m/s for F4 (sensitivity 94.1%, specificity 86.8%). Ultrasonic ARFI elastography is a novel, non-invasive and reliable method for the assessment of liver fibrosis in patients with chronic liver disease.

Feasibility of the use of a novel soft tissue stiffness meter

Simple but objective measurement of soft tissue consistency would be advantageous in the assessment of many neurological, lymphostatic and venous disorders. The aim of the present study was to evaluate the feasibility of using a novel hand-held computerized soft tissue stiffness meter (STSM). The STSM describes the soft tissue stiffness (STS) in the form of the instantaneous force (N) by which the tissue resists the constant deformation produced by a cylindrical intender. Firstly, the STSM was used to test elastomer samples with known mechanical properties. In the in vivo assessment, 12 healthy, nondisabled adults (age range, 24–57 years) and 16 subjects with chronic myofascial neck pain syndrome (age range, 27–55 years) were studied. To study the reproducibility (coefficient of variation (CV(%))) of the method, the measurement sites were either marked with a marker pen (marked points) or localized anatomically (unmarked points). Measurements were made from the dorsal forearm (Arm), trapezius (Tra), levator scapulae (Lev), infraspinatus (Inf) and deltoideus (Del) muscle areas. STS in the forearm was studied during different types of short-term relative isometric loading of the muscle as well as during venous occlusion. STS values of the myofascial trigger points in the Lev muscles were evaluated bilaterally. A linear, positive relationship was found between the indenter force (N) and the dynamic compressive modulus (MPa) of elastomer stiffness (r2 = 0.90, n = 9). Intra- and interrater CVs of marked and unmarked sites varied between 4.31% and 12.06%. STS increased linearly along the relative muscle load (r2 = 0.96) and nonlinearly during the venous occlusion (r2 = 0.97). Statistically significant regional variation of STS was found between the different measurement sites (p < 0.05). In conclusion, STSM can evaluate tissue stiffness quantitatively and yield reproducible data.