Search results for "Elasticity"
showing 10 items of 736 documents
Diagnostic performance of 2D-shear wave elastography in the diagnosis of breast cancer: a clinical appraisal of cutoff values
2022
Purpose To assess the role of 2D-shear wave elastography (2D-SWE) in differentiating benign from malignant focal breast lesions (FBLs), providing new vendor-specific cutoff values. Methods 158 FBLs (size: 3.5-50 mm) detected in 151 women (age: 21-87 years) were prospectively evaluated by means 2D-SWE. For each lesion, an expert radiologist assessed US BI-RADS category and calculated the following four 2D-SWE parameters: (1) elasticity maximum (E-max); (2) mean elasticity (E-mean); (3) minimum elasticity (E-min); (4) elasticity ratio (E-ratio). US-guided core-biopsy was considered as standard of reference for all the FBLs classified as BI-RADS 4 or 5. For each 2D-SWE parameter, the optimal c…
Is local stiffness, as measured by radio frequency, more sensitive than intima-media thickness?
2013
Aim: The aim of our study was to explore the changes in common carotid arterial intima-media thickness (CCA IMT) and local arterial stiffness to evaluate, non-invasively, early vascular disease in patients with cardiovascular (CV) risk factors and "normal" carotid IMT (6.05 m/s better identified, among patients with IMT <0.9mm, those with cardiovascular risk factors (sensitivity 82.0 % specificity 62.0 %; AUC 0.73). Conclusion. Increased stiffness is a result of change both in quantity and quality of the arterial wall. Arterial functional changes and distention alterations may herald the onset of vascular disease before manifestation of symptoms or detection of preclinical atherosclerotic l…
EMG-Assisted Muscle Force Driven Finite Element Model of the Knee Joint with Fibril-Reinforced Poroelastic Cartilages and Menisci.
2019
Abnormal mechanical loading is essential in the onset and progression of knee osteoarthritis. Combined musculoskeletal (MS) and finite element (FE) modeling is a typical method to estimate load distribution and tissue responses in the knee joint. However, earlier combined models mostly utilize static-optimization based MS models and muscle force driven FE models typically use elastic materials for soft tissues or analyze specific time points of gait. Therefore, here we develop an electromyography-assisted muscle force driven FE model with fibril-reinforced poro(visco)elastic cartilages and menisci to analyze knee joint loading during the stance phase of gait. Moreover, since ligament pre-st…
Trabecular trajectory in the articular processes of the human fourth cervical vertebra
2001
The articular processes (AP) of the neural arch have been implicated in weight transmission through the cervical spine. To analyse the mechanism of weight transmission in the AP, we studied the direction of forces within it, in particular, the pattern of trabecular trajectories. Twenty-two AP from C4 vertebrae were studied in anatomical sections, and corresponding photoelastic models from selected sections were constructed and analysed. Anatomical and photoelastic findings show the subarticular spongiosa of the superior articular process (SAP) to be orthogonally arranged with vertical and oblique trabeculae in the direction of compressive forces and additional trabeculae always oriented per…
Neuromuscular function and mechanical efficiency of human leg extensor muscles during jumping exercises
1982
The influence of prestretch amplitude on the mechanical efficiency was examined with 5 subjects, who performed 5 different series of vertical jumps, each of which differed with respect to the mechanics of the knee joint action during the prestretch (eccentric) phase of the contact on the floor. Electromyographic activity was recorded from the major extensor muscles during the entire work period of 1 min per series. In addition, expired air was collected during the test and recovery for determination of energy expenditure. Mechanical work was calculated from the vertical displacement of the body during the jumps. The results indicated that high net efficiency of 38.7% was observed in conditi…
"Dangerous liaisons: NAFLD and liver fibrosis increase cardiovascular risk in HIV".
2022
Objectives Non-alcoholic fatty liver disease (NAFLD) is strongly associated with cardiovascular disease in the general population. We aimed to assess the impact of NAFLD and liver fibrosis on intermediate-high cardiovascular risk in people living with HIV. Methods We included people living with HIV from three cohorts. NAFLD and significant liver fibrosis were defined using transient elastography: controlled attenuation parameter >= 288 dB/m and liver stiffness measurement >= 7.1 kPa, respectively. Cardiovascular risk was assessed with the atherosclerotic cardiovascular disease (ASCVD) risk estimator in patients aged between 40 and 75 years and categorised as low if <5%, borderline …
Suboptimal performance of APRI and FIB-4 in ruling out significant fibrosis and confirming cirrhosis in HIV/HCV co-infected and HCV mono-infected pat…
2018
Purpose: We aimed to assess the diagnostic reliability of two indirect biomarkers, APRI and FIB-4, for the staging of liver fibrosis using transient elastography (TE) as reference standard, among HIV/HCV co-infected and HCV mono-infected patients. Methods: This is an observational, retrospective study on subjects who had access to the RESIST HCV from October 2013 to December 2016, a regional network encompassing 22 hospitals and academic centers throughout Sicily. Sensitivity, specificity and diagnostic accuracy of indirect biomarkers for liver stiffness measurement (LSM) < 9.5 kPa (significant fibrosis) and LSM ≥ 12.5 kPa (cirrhosis) were determined by receiver operator characteristics …
Usefulness of the index of NASH - ION for the diagnosis of steatohepatitis in patients with non-alcoholic fatty liver: An external validation study
2018
Background & Aims The non-invasive identification of steatohepatitis (NASH) in patients with Non-Alcoholic Fatty Liver Disease is an unmet need in clinical practice. Index of NASH (ION) is a new tool for the prediction of NASH. We aimed to externally validate ION and to compare it with CK-18. Since necroinflammation precedes fibrosis, we also tested ION in combination with non-invasive tools for fibrosis. Methods We analysed data from 292 Italian patients (169 Southern cohort, and 123 Northern cohort) with an histological diagnosis of NAFLD. The ION, FIB-4 and NFS scores were calculated according to published algorithms. Serum cytokeratin18-Aspartate396 levels and liver stiffness (LS) by Fi…
Comparison of Histochemical Stainings in Evaluation of Liver Fibrosis and Correlation with Transient Elastography in Chronic Hepatitis.
2015
Background and Aim. The best staining to evaluate liver fibrosis in liver hepatitis is still a debated topic. This study aimed to compare Masson’s trichrome (MT), Sirius Red (SR), and orcein stainings in evaluating liver fibrosis in chronic HCV hepatitis (CHC) with semiquantitative and quantitative methods (Collagen Proportionate Area (CPA) by Digital Image Analysis (DIA)) and correlate them with transient elastography (TE).Methods. Liver stiffness evaluation of 111 consecutive patients with CHC was performed by TE. Semiquantitative staging by Metavir score system and CPA by DIA were assessed on liver biopsy stained with MT, SR, and orcein.Results. MT, SR, and orcein staining showed concord…
Prospective comparison of Fibroscan, King's score and liver biopsy for the assessment of cirrhosis in chronic hepatitis C infection
2010
Historically, liver biopsy (LB) was the sole method to evaluate the severity of hepatic fibrosis in patients with chronic hepatitis C infection. However, LB is expensive and associated with a risk of severe complications. Therefore, noninvasive tests have been developed to assess the severity of liver fibrosis. The accuracy of Fibroscan (FS) and King's score (KS) was evaluated individually and in combination using liver histology as the reference standard. One hundred and eighty-seven patients were identified who had undergone a biopsy with a diagnosis of chronic hepatitis C virus (HCV) mono-infection (HCV RNA-positive by RT-PCR), attending King's College Hospital (n = 88) or the Royal Free…