• elastography pancreas рSWE shear wave ultrasound

• Elasticity Imaging Techniques/methods
• Reference Values
• Pancreas/diagnostic imaging

Ultrasound elastography (USE) is a modality that in addition to fundamental B-mode, Doppler, and contrast-enhanced sonography is suitable to make qualitative and quantitative statements about the stiffness of tissues. Introduced more than 20 years ago in adults, USE becomes now a diagnostic tool also in children. The aim of this paper is to describe current available techniques for USE in children. The significance for routine use in children is shown, and further interesting applications are reported.

• Acoustic radiation force impulse
• Shear wave elastography
• Transient elastography
• Ultrasound elastography

Introduction: A variety of imaging techniques exists for the diagnosis of pancreatic disorders. None of the broadly applied diagnostic methods utilizes elasticity as an indicator of tissue damage. A well-known fact is that both chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDA) are associated with the development of prominent fibrosis (increased tissue stiffness). Purpose: To prospectively assess the accuracy of point shear wave elastography (pSWE) in differentiating between benign and malignant pancreatic diseases, establish a cut-off value for the diagnosis of PDA, and evaluate the influence of certain variables on the obtained results. Materials and methods: The present study included 78 patients who were admitted at the Department of Gastroenterology at the university hospital “Kaspela” between December 2017 and August 2021 for diagnosis and/or treatment of pancreatic disorders. Based on the clinical criteria, diagnostic imaging, and histological findings, patients were divided into the CP and PDA group. The ultrasound based pSWE technique was applied and shear wave velocity (SWV) was measured. The depth of region of interest (ROI) and successful measurement rate were also recorded. Results: The mean ± SD SWV values established through pSWE were 1.75 ± 0.34 m/s and 2.93 ± 0.91 m/s for the CP and PDA, respectively. With a cut-off value of 2.09 m/s, we calculated the sensitivity (Se), specificity (Sp), and accuracy for differentiating between CP and PDA of 89.47%, 91.20%, and 88.60%, respectively. Of the examined variables, BMI and depth of ROI in the CP group and sex in the PDA group showed a statistically significant influence on the obtained results. Conclusions: pSWE may be utilized as a differential diagnostic modality in patients with suspected CP or PDA.

• Hepatocellular carcinoma
• Liver stiffness
• Refractory ascites
• Virtual touch quantification

• Animals
• Cysts/diagnostic imaging
• Diagnosis, Differential
• Echinococcosis
• Elasticity Imaging Techniques
• Female
• Humans
• Liver/diagnostic imaging
• Male
• Sheep

• alanine aminotransferase
• liver disease
• lymphatic vessels
• splenic stiffness measurement

• acoustic radiation force impulse
• elastography
• intestinal fibrosis
• living donor kidney transplantation
• normal kidney
• shear wave velocity

• Adult
• Elasticity Imaging Techniques
• Female
• Humans
• Image Interpretation, Computer-Assisted
• Kidney/diagnostic imaging
• Kidney/pathology
• Kidney Transplantation
• Living Donors
• Male
• Prospective Studies
• Sensitivity and Specificity

• acoustoelasticity
• quasi-static and shear wave elastography
• nonlinear shear modulus
• nonlinear elasticity
• material nonlinearity
• simple shearing
• complex tissue motion

• Elasticity
• Elasticity Imaging Techniques
• Motion
• Phantoms, Imaging
• Signal-To-Noise Ratio

• R21 EB017503 NIBIB NIH HHS

• ARFI
• Gaucher disease
• Liver
• Point shear wave elastography
• Spleen

• Acoustics
• Adolescent
• Adult
• Aged
• Biomarkers/analysis
• Child
• Child, Preschool
• Elasticity Imaging Techniques/methods
• Female
• Follow-Up Studies
• Gaucher Disease/diagnostic imaging
• Gaucher Disease/physiopathology
• Humans
• Liver/diagnostic imaging
• Liver/pathology
• Male
• Middle Aged
• Prognosis
• Reproducibility of Results
• Retrospective Studies
• Severity of Illness Index
• Spleen/diagnostic imaging
• Spleen/pathology
• Young Adult

The clinical ultrasound community demands mechanisms to obtain the viscoelastic biomarkers of soft tissue in order to quantify the tissue condition and to be able to track its consistency. Torsional Wave Elastography (TWE) is an emerging technique proposed for interrogating soft tissue mechanical viscoelastic constants. Torsional waves are a particular configuration of shear waves, which propagate asymmetrically in-depth and are radially transmitted by a disc and received by a ring. This configuration is shown to be particularly efficient in minimizing spurious p-waves components and is sensitive to mechanical constants, especially in cylinder-shaped organs. The objective of this work was to validate (TWE) technique against Shear Wave Elasticity Imaging (SWEI) technique through the determination of shear wave velocity, shear moduli, and viscosity of ex vivo chicken liver samples and tissue mimicking hydrogel phantoms. The results of shear moduli for ex vivo liver tissue vary 1.69–4.0kPa using TWE technique and 1.32–4.48kPa using SWEI technique for a range of frequencies from 200 to 800Hz. Kelvin–Voigt viscoelastic parameters reported values of μ = 1.51kPa and η = 0.54Pa·s using TWE and μ = 1.02kPa and η = 0.63Pa·s using SWEI. Preliminary results show that the proposed technique successfully allows reconstructing shear wave velocity, shear moduli, and viscosity mechanical biomarkers from the propagated torsional wave, establishing a proof of principle and warranting further studies.

• Kelvin–Voigt viscoelasticity
• Shear Wave Elastography Imaging
• Torsional Wave Elastography
• mechanical biomarkers
• tissue biomarkers

Shear wave elastography (SWE) imaging have been proposed for characterization of focal liver lesions. We conducted a meta-analysis to evaluate the accuracy and clinical utility of SWE imaging for differentiation of malignant and benign hepatic lesions.

PubMed, Embase, Web of Science, and the Cochrane Library were systematically reviewed to search for studies published between January 1, 1990, and November 30, 2018. The studies published in English relating to the evaluation the diagnostic accuracy of SWE imaging for distinguishing malignant and benign liver lesions were retrieved and examined for pooled sensitivity, specificity, likelihood ratios, and diagnostic odds ratios, using bivariate random-effects models. The hierarchical summary receiver operating characteristic (HSROC) curve was estimated to assess the SWE imaging accuracy. The clinical utility of SWE imaging for differentiation of malignant liver lesions was evaluated by Fagan plot.

A total of 15 studies, involving 1894 liver lesions in 1728 patients, were eligible for the meta-analysis. The pooled sensitivity and specificity for identification of malignant liver lesions were 0.82 (95% CI: 0.77–0.86) and 0.82 (95% CI: 0.76–0.87), respectively. The AUC was 0.89 (95% CI: 0.86–0.91). When the pre-test probability was 50%, after SWE imaging measurement over the cut-off value (positive result), the corresponding post-test probability for the presence of malignant liver lesions was 82%; the post-test probability was 18% after negative measurement.

SWE imaging showed high sensitivity and specificity in differentiating malignant and benign liver lesions and may be promising for noninvasive evaluation of liver lesions.

The review was registered in the International Prospective Register of Systematic Reviews (PROSPERO): CRD42018104510.

The online version of this article (10.1186/s12876-019-0976-2) contains supplementary material, which is available to authorized users.

• Diagnosis
• Elasticity imaging techniques
• Liver neoplasms
• Meta-analysis
• Ultrasonography

• acoustic radiation force impulse imaging
• breast (diagnostic)
• breast cancer
• qualitative analysis
• quantitative analysis

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Breast/diagnostic imaging
• Breast Neoplasms/diagnostic imaging
• Diagnosis, Differential
• Elasticity Imaging Techniques/methods
• Evaluation Studies as Topic
• Female
• Humans
• Middle Aged
• Reproducibility of Results
• Ultrasonography, Mammary/methods
• Young Adult

• Hashimoto's thyroiditis
• Shear wave elastography
• Ultrasonography
• Virtual touch tissue quantification techniques

• Adult
• Diagnosis, Differential
• Elasticity Imaging Techniques/methods
• Female
• Hashimoto Disease/diagnostic imaging
• Humans
• Image Processing, Computer-Assisted/methods
• Male
• Middle Aged
• Prospective Studies
• Reproducibility of Results
• Sensitivity and Specificity
• Thyroid Gland/diagnostic imaging

• Algorithms
• Computer Simulation
• Elasticity Imaging Techniques/methods
• Humans
• Models, Theoretical
• Phantoms, Imaging
• Shear Strength
• Transducers

• R01 DK092255 NIDDK NIH HHS
• R01 EB012079 NIBIB NIH HHS
• R21 CA121235 NCI NIH HHS
• R21 EB023051 NIBIB NIH HHS

• Cirrhosis
• Liver stiffness
• Point shear wave elastography
• Real-time shear wave elastography
• Shear wave elastography

The purpose of the study is to investigate the usefulness of acoustic radiation force impulse (ARFI) elastography in the characterization of focal solid liver lesions as benign, malignant, or metastatic using ARFI two-dimensional (2D) imaging and ARFI quantification (shear wave velocities [SWVs]).

Sixty lesions were included in this study. The lesions were classified into three groups: Group I included benign lesions (n = 25), Group II included malignant lesions (n = 27), and Group III included metastatic lesions (n = 8). ARFI elastography was performed in all these patients using a Siemens ACUSON S 2000™ ultrasound machine. Stiffness and size of the lesions were assessed on ARFI 2D images in correlation with B-mode ultrasound images. SWVs were obtained in these lesions for the quantification of stiffness.

In ARFI 2D images, malignant lesions were predominantly stiffer and larger, while benign lesions were softer and similar in size (P < 0.05). The mean SWVs in benign, malignant, and metastatic lesions were 1.30 ± 0.35 m/s, 2.93 ± 0.75 m/s, and 2.77 ± 0.90 m/s, respectively. The area under receiver operating characteristic curve of SWV for differentiating benign from malignant lesions was 0.877, suggesting fair accuracy (95% confidence interval: 0.777–0.976); with a cutoff value of 2 m/s, showing sensitivity: 92%; specificity: 96%; positive predictive value: 96%; negative predictive value: 93% (P < 0.05). Statistically significant difference exists in SWV of benign and malignant or metastatic lesions.

ARFI elastography with 2D imaging and quantification might be useful in the characterization of benign and malignant liver lesions.

• Acoustic radiation force impulse
• elasticity imaging
• elastography
• liver tumors
• shear wave velocities

• Fibrosis
• Imaging
• Liver
• Non-tumorous
• Steatosis

• ARFI elastography
• Botulinum toxin A
• Cerebral palsy
• Gastrocnemius muscle
• Muscle spasticity

• ARFI imaging
• Elasticity
• Sonoelastography
• Strain imaging
• Supersonic imaging
• Transient elastography
• Ultrasound
• Vibro-acoustography

The many factors influencing the shear wave velocity (SWV) measured with Acoustic Radiation Force Impulse (ARFI) are examined in order to define the most correct examination technique. In particular, attention is given to the information achieved by experimental models, such as phantoms and animal studies. This review targets the clinical applications of ARFI in the evaluation of chronic diffuse disease, especially of liver and kidneys. The contribution of ARFI to the clinical workout of these patients and some possible perspectives are described.

• Stiffness significantly varies among normal and abnormal biological tissues.

• In clinical applications physical, geometrical, anatomical and physiological factors influence the SWV.

• Elastographic techniques can quantify fibrosis, which is directly related to stiffness.

• ARFI can be useful in chronic diffuse disease of liver and kidney.

• Anisotropy
• Elasticity imaging techniques
• Fibrosis
• Kidney diseases
• Liver cirrhosis

• EUROPEAN SOCIETY OF RADIOLOGY

• Elasticity Imaging Techniques/methods
• Humans
• Liver/diagnostic imaging
• Liver Cirrhosis/diagnostic imaging
• Radiologists
• Societies, Medical

To compare several noninvasive indices of fibrosis in chronic viral hepatitis B, including liver shear-wave velocity (SWV), hyaluronic acid (HA), collagen type IV (CIV), procollagen type III (PCIII), and laminin (LN).

Acoustic radiation force impulse (ARFI) was performed in 157 patients with chronic viral hepatitis B and in 30 healthy volunteers to measure hepatic SWV (m/s) in a prospective study. Serum markers were acquired on the morning of the same day of the ARFI evaluation. Receiver operating characteristic (ROC) analysis was performed to evaluate and compare the accuracies of SWV and serum markers using METAVIR scoring from liver biopsy as a reference standard.

The most accurate test for diagnosing fibrosis F ≥ 1 was SWV with the area under the ROC curve (AUC) of 0.913, followed by LN (0.744), HA (0.701), CIV (0.690), and PCIII (0.524). The best test for diagnosing F ≥ 2 was SWV (AUC of 0.851), followed by CIV (0.671), HA (0.668), LN (0.562), and PCIII (0.550). The best test for diagnosing F ≥ 3 was SWV (0.854), followed by CIV (0.693), HA (0.675), PCIII (0.591), and LN (0.548). The best test for diagnosing F = 4 was SWV (0.965), followed by CIV (0.804), PCIII (0.752), HA (0.744), and LN (0.662). SWV combined with HA and CIV did not improve diagnostic accuracy (AUC = 0.931 for F ≥ 1, 0.863 for F ≥ 2, 0.855 for F ≥ 3, 0.960 for F = 4).

The performance of SWV in diagnosing liver fibrosis is superior to that of serum markers. However, the combination of SWV, HA, and CIV does not increase the accuracy of diagnosing liver fibrosis and cirrhosis.

• ARFI imaging
• Chronic hepatitis B
• Liver fibrosis
• Serum markers

Following injurious stimuli, quiescent hepatic stellate cells (qHSCs) transdifferentiate into activated HSCs (aHSCs). aHSCs play pivotal roles in the onset and progression of liver fibrosis. Therefore, molecular imaging of aHSCs in liver fibrosis will facilitate early diagnosis, prognosis prediction, and instruction and evaluation of aHSC-targeted treatment. To date, several receptors, such as integrin αvβ3, mannose 6-phosphate/insulin-like growth factor II receptor (M6P/IGF-IIR), collagen type VI receptor (CVIR), platelet-derived growth factor receptor-β (PDGFR-β), vimentin, and desmin, have been identified as biomarkers of aHSCs. Corresponding ligands to these receptors have also been developed. This review will discuss strategies for developing aHSC-targeted imaging in liver fibrosis.

• Activated hepatic stellate cells (aHSCs)
• Biomarkers
• Ligands
• Liver fibrosis
• Molecular imaging

Recent interests have focused on the exploration of the mechanical properties (elasticity, stiffness and deformity) of parenchymatous organs using tissue strain imaging techniques and elastosonography. Measures of the mechanical properties of the kidneys have given conflicting results. There are various conditions that affect the variability of renal parenchymal measures, the main target of the investigations. They can be classified as intrinsic (depending upon the patient), extrinsic (depending upon the operator) and mixed (both intrinsic and extrinsic). Indeed, the mechanical properties of the kidney depend on various conditions that alter its histology, mainly the amount of fibrosis in the renal parenchymal interstitium. Anatomical factors play an important role because the kidney is a highly anisotropic organ with important differences when considering the cortex and the medulla. Physical factors include the frequency of the probe, compression and distance from source to target. Many factors can affect measurements and it is necessary to find an accurate technique in order to avoid mistakes and to obtain reproducible data. Indeed, it is imperative to define a standardized examination technique in order to get comparable results. Therefore, the utility of acoustic radiation force imaging technique to predict only renal fibrosis or progression of chronic kidney disease is of dubious value because several variables - blood perfusion and urinary pressure - can contribute to a given measure, even with a standardized method able to minimize intra- and inter-operator variability.

• Elastosonography
• Acoustic radiation force imaging technique
• Renal elasticity
• Renal fibrosis
• Chronic kidney disease

• Acoustic radiation force impulse
• Elastography
• Thyroid nodule
• Ultrasound

• Adolescent
• Adult
• Aged
• Elasticity Imaging Techniques/methods
• Female
• Humans
• Image Enhancement/methods
• Image Interpretation, Computer-Assisted/methods
• Male
• Middle Aged
• Observer Variation
• Reproducibility of Results
• Sensitivity and Specificity
• Single-Blind Method
• Thyroid Nodule/diagnostic imaging
• Young Adult

• acoustic radiation force impulse (ARFI)
• focal liver lesions
• ultrasound

• Adult
• Aged
• Diagnosis, Differential
• Elasticity Imaging Techniques
• Female
• Humans
• Liver/diagnostic imaging
• Liver Diseases/diagnostic imaging
• Liver Neoplasms/diagnostic imaging
• Male
• Middle Aged
• Prospective Studies
• ROC Curve
• Reproducibility of Results
• Sensitivity and Specificity

• Drug Delivery Systems/methods
• Humans
• Molecular Imaging/methods
• Ultrasonography/methods
• Ultrasonography, Interventional

• EB002349 NIBIB NIH HHS
• R01 EB001826 NIBIB NIH HHS
• R01 HL090700 NHLBI NIH HHS
• EB001826 NIBIB NIH HHS
• R21 DK093841 NIDDK NIH HHS
• DK093841 NIDDK NIH HHS
• EB016752 NIBIB NIH HHS
• R21 EB016752 NIBIB NIH HHS
• HL111077 NHLBI NIH HHS
• CA102880 NCI NIH HHS
• HL090700 NHLBI NIH HHS
• R01 EB002349 NIBIB NIH HHS
• R21 CA102880 NCI NIH HHS
• R33 CA102880 NCI NIH HHS
• R01 HL111077 NHLBI NIH HHS

• Elasticity Imaging Techniques/methods
• Humans
• Liver Cirrhosis/diagnostic imaging
• Liver Cirrhosis/pathology
• Practice Guidelines as Topic
• Radiology
• Reference Standards
• Societies, Medical
• Ultrasonics

• (170.7170) ultrasound
• (170.5120) photoacoustic imaging
• (170.0180) microscopy

• P41 EB002182 NIBIB NIH HHS
• R01 EB012058 NIBIB NIH HHS

• Acoustic radiation force impulse
• Fetal growth restriction
• Placental elasticity
• Placental histological change
• Pregnancy induced hypertension
• Virtual touch tissue quantification

• Elasticity measurements during labour
• Myometrium contraction
• Shear wave elastography
• Tocodynamometer
• Uterine elasticity

• Elasticity Imaging Techniques/methods
• Feasibility Studies
• Female
• Humans
• Labor, Obstetric/physiology
• Myometrium/physiology
• Pregnancy
• Uterine Contraction/physiology

• Adolescent
• Adult
• Aged
• Case-Control Studies
• Elasticity Imaging Techniques/methods
• Female
• Humans
• Male
• Middle Aged
• Renal Insufficiency, Chronic/diagnostic imaging
• Renal Insufficiency, Chronic/pathology
• Sensitivity and Specificity