B-mode ultrasonography and ARFI elastography of articular and peri-articular structures of the hip joint in non-dysplastic and dysplastic dogs as confirmed by radiographic examination.

BACKGROUND: Canine hip dysplasia is a common orthopedic disease in veterinary practice. The diagnosis is made by radiographic examinations that evaluate bone alterations associated with hip dysplasia. Although radiographic examination is the gold standard for diagnosis, it does not allow a detailed evaluation of soft tissues such as the joint capsule and periarticular muscles. This study aimed to evaluate the accuracy of B-mode ultrasonography and acoustic radiation force impulse (ARFI) elastography in assessing the joint capsule and periarticular muscles of dogs using the Orthopedic Foundation of Animals (OFA) classification and the distraction index (DI) in the early and late diagnosis of hip dysplasia. This study sought to propose a protocol for the ultrasonographic evaluation of the structures involved in canine hip dysplasia. METHODS: Radiographic and ultrasonographic evaluations were performed on 108 hip joints of 54 dogs. Thirty dogs were older than 2 years and 24 were aged between 4 and 10 months. RESULTS: It was verified that an increase in pectineus muscle stiffness (cutoff value > 2.77 m/s) by elastography in some dysplastic dogs and an increase in the thickness of the joint capsule (cutoff value > 0.9 mm) in B-mode ultrasonography, were associated with a distraction index > 0.5, with both having a positive correlation. In B-mode ultrasonographic evaluation, the presence of signs of degenerative joint disease, such as irregularities of the cranial edge of the acetabulum and femoral head, were associated with a distraction index > 0.5 in canines, with a specificity of 94%. In adult dogs, the findings of degenerative joint disease on ultrasound were associated with a diseased OFA classification (P < 0.05). Measurement of the joint capsule > 1.10 mm was diagnostic for dysplasia in unhealthy dogs by OFA. CONCLUSIONS: ARFI elastography has shown that the pectineus muscle may experience changes in stiffness in dysplastic animals. Additionally, changes in joint capsule thickness can be identified in B-mode in young and adult dogs with dysplastic joints, which contributes to the diagnosis of hip dysplasia.

Effects of Shear Stress Waves on Meat Tenderness: Ultrasonoporation.

Meat is an important part of the food pyramid in Mexico, to such an extent that it is included in the basic food basket. In recent years, there has been great interest in the application of so-called emerging technologies, such as high-intensity ultrasound (HIU), to modify the characteristics of meat and meat products. The advantages of the HIU in meat such as pH, increased water-holding capacity, and antimicrobial activity are well documented and conclusive. However, in terms of meat tenderization, the results are confusing and contradictory, mainly when they focus on three HIU parameters: acoustic intensity, frequency, and application time. This study explores via a texturometer the effect of HIU-generated acoustic cavitation and ultrasonoporation in beef (m. Longissimus dorsi). Loin-steak was ultrasonicated with the following parameters: time tHIU = 30 min/each side; frequency fHIU = 37 kHz; acoustic intensity IHIU = ~6, 7, 16, 28, and 90 W/cm2. The results showed that acoustic cavitation has a chaotic effect on the loin-steak surface and thickness of the rib-eye due to Bjerknes force, generating shear stress waves, and acoustic radiation transmittance via the internal structure of the meat and the modification of the myofibrils, in addition to the collateral effect in which the collagen and pH generated ultrasonoporation. This means that HIU can be beneficial for the tenderization of meat.

Application of acoustic radiation force impulse elastography combined with serum markers in Child-Pugh grading

OBJECTIVES: Acoustic radiation force impulse (ARFI) elastography, the aspartate aminotransferase-to-alanine aminotransferase ratio (AAR), aspartate aminotransferase-to-platelet ratio index (APRI), and the fibrosis-4 (FIB-4) index are widely used to assess liver fibrosis. However, efficacies of these methods in the evaluation of hepatic functional reserve remain unclear. In this study, we investigated the relationship between ARFI elastography combined with either AAR, APRI, or FIB-4 index and Child-Pugh (CP) class for the evaluation of hepatic functional reserve in patients with chronic hepatitis B (CHB)-related cirrhosis. METHODS: The shear wave velocities of 104 patients with clinically confirmed CHB-related cirrhosis were determined using the ARFI; and clinical serum markers (e.g. ALT, AST, PLT) were used to calculate the AAR, APRI, and FIB-4 index. Cirrhosis patients were scored according to their CP class. The ARFI, AAR, APRI, and FIB-4 index were compared with the CP class. The efficacy of each indicator in diagnosis was analyzed using the receiver operating characteristic (ROC) curve and the ARFI combined with either the AAR, APRI, or FIB-4 index, which is used to predict decompensated cirrhosis. RESULTS: No significant differences were observed in gender and age among CP classes A, B, and C patients (p>0.05). The ARFI values and the AAR, APRI, and FIB-4 index of patients with CP classes A, B, and C were significantly different (p<0.05). With an increasing CP class, the ARFI, AAR, APRI, and FIB-4 values increased. The correlation between the ARFI and the CP class was stronger than that between the AAR, APRI, and FIB-4 index and the CP class. The area under the ROC curve for the diagnosis of decompensated cirrhosis using the ARFI was 0.841, which was higher than that for the AAR, APRI, and FIB-4 index. According to the area under the curve results, no significant differences were found when the ARFI was combined with either the AAR, APRI, or FIB-4 index and when the ARFI alone was used. CONCLUSIONS: The ARFI value has a strong correlation with the CP class. Therefore, ARFI elastography complements CP class in the assessment of the hepatic functional reserve in patients with CHB-related cirrhosis.

Acoustic Radiation Force Impulse (ARFI) Elastography in Autoimmune and Cholestatic Liver Diseases.

INTRODUCTION: Acoustic Radiation Force Impulse (ARFI) elastography evaluates hepatic fibrosis non-invasively and has been mainly validated in viral hepatitis. Data on rare liver diseases such as autoimmune hepatitis (AIH), overlap syndrome, primary biliary cholangitis (PBC) or primary sclerosing cholangitis (PSC) are sparse. MATERIAL AND METHODS: 85 patients (including 31 AIH, 26 PBC, 16 PSC and 3 PSC-and 9 PBC-AIH-overlap syndromes) were retrospectively analysed pointing at ARFI elastography of the liver and the correlation with histologic Ishak fibrosis score (F0-6). Results of shear wave velocities (m/s) were expressed as mean ± standard deviation. RESULTS: The mean shear wave velocity of all 85 patients showed 1.80 ± 0.84 m/s (0.74-3.98). The ARFI elastography values correlated with the degree of fibrosis in all patients overall and in patients with AIH, overlap syndrome and PSC, respectively. The subgroup of 26 patients with PBC (only with Ishak F > 3) revealed no correlation between ARFI and these early fibrosis stages (r = 0.019, p = 0.927). ARFI elastography correlated with bilirubin, AST, but not with patient age, body mass index or measurement depth. The cut-off of 2.04 m/s for detecting cirrhosis (Ishak F > 5) leads to a sensitivity of 90.0% and specificity of 74.7% (AUROC 87.2%). CONCLUSION: ARFI elastography can evaluate fibrosis in AIH, PSC and PSC-/PBC-AIH-overlap syndrome with good accuracy for the detection of hepatic cirrhosis. Shear wave velocities in PBC should be interpreted with caution in early stages of fibrosis.

Acoustic Radiation Force Impulse Elastography with APRI and FIB-4 to Identify Significant Liver Fibrosis in Chronic Hepatitis B Patients.

INTRODUCTION AND AIM: In chronic hepatitis B (CHB) patients with equivocal indication for antiviral therapy, therapeutic decision currently depends on histopathology of the liver. We aimed to evaluate if acoustic radiation force impulse (ARFI) in conjunction with aspartate transaminase to platelet ratio index (APRI) and fibrosis-4 (FIB-4) score could replace liver biopsy to indicate treatment for CHB. MATERIAL AND METHODS: We prospectively enrolled 101 clinically non-cirrhotic patients whose serum alanine aminotransferase was mildly elevated (1-2 folds above the upper normal limit) despite a high viral load (HBV DNA > 2,000 IU/mL). All participants underwent liver biopsy, and measurement of ARFI, APRI and FIB-4. The ability of the markers to distinguish fibrosis ≥ METAVIR F2 was evaluated. RESULTS: According to histopathology, liver fibrosis was METAVIR F0 in 2 (2.0%), F1 in 43 (42.6%), F2 in 34 (33.7%), F3 in 16 (15.8%), and F4 in 6 (5.9%) patients, and was correlated with ARFI (p = 0.0001), APRI (p = 0.012), and FIB-4 (p = 0.004). The six patients with cirrhosis were included for analysis, and received antiviral therapy. The C statistics of ARFI, APRI, and FIB-4 for fibrosis ≥ F2 were 0.70 (95% confidence interval [CI], 0.59-0.80), 0.62 (95% CI, 0.51-0.73), and 0.64 (0.53- 0.75), respectively. The cut-off values for 95% sensitivity and 95% specificity to identify significant fibrosis were 0.97 m/sec and 1.36 m/sec for ARFI, 0.36 and 1.0 for APRI, 0.63 and 2.22 for FIB-4, respectively. Using a combination of these 3 indices, 44 patients (43.6%) could be spared a liver biopsy procedure. CONCLUSIONS: A combination of ARFI, APRI, and FIB-4 may spare some CHB patients with equivocal indication for antiviral treatment a liver biopsy.

Acoustic radiation force and torque exerted on a small viscoelastic particle in an ideal fluid.

We provide a detailed analysis on the acoustic radiation force and torque exerted on a homogeneous viscoelastic particle in the long-wave limit (i.e. the particle radius is much smaller than the incident wavelength) by an arbitrary wave. We assume that the particle behaves as a linear viscoelastic solid, which obeys the fractional Kelvin-Voigt model. Simple analytical expressions for the radiation force and torque are obtained. The developed theory is used to describe the interaction of acoustic waves (traveling and standing plane waves, and zero- and first-order Bessel beams) in the MHz-range with polymeric particles, namely lexan, low-density (LDPE) and high-density (HDPE) polyethylene. We found that particle absorption is chiefly the cause of the radiation force due to a traveling plane wave and zero-order Bessel beam when the frequency is smaller than 5MHz (HDPE), 3.9MHz (LDPE), and 0.9MHz (lexan). Whereas in a standing wave field, the radiation force is mildly changed due to dispersion inside the particle. We also show that the radiation torque caused by a first-order Bessel beam varies nearly quadratic with frequency. These findings may enable new possibilities of particle handling in acoustophoretic techniques.

Métodos diagnósticos en hipertensión portal / Diagnostic Methods in Portal Hypertension

La hipertensión portal en el curso natural de las enfermedades hepáticas es una de las complicaciones más frecuentes resultado del aumento de la resistencia vascular hepática que determina el desarrollo de otros sucesos responsables de la mayor mortalidad en pacientes con hepatopatías. En consecuencia, el conocimiento de la fisiopatología de la hipertensión portal y de sus causas representa un factor importante para su adecuado manejo y el de las demás complicaciones relacionadas. Es así como se cuentan con métodos diagnósticos de diferentes tipos para la detección temprana y adecuada de dicha entidad; lo cual, además, corresponde al objetivo de la presente revisión: dar una mirada a los métodos diagnósticos utilizados para la detección de hipertensión portal, disponibles en la actualidad.

Portal hypertension is one of the most frequent complications in the natural course of liver disease. It results from increased hepatic vascular resistance and determines the development of other events responsible for increased mortality in patients with liver disease. Consequently, knowledge of the pathophysiology of portal hypertension and its causes is an important factor for handling it and related complications proper. Explanation of the various diagnostic methods for early and appropriate detection is one of the objectives of this review which will take a look at diagnostic methods available and in use for the detection of portal hypertension.

Acoustic radiation force impulse elastography and serum fibrosis markers in chronic hepatitis C.

OBJECTIVE: Liver biopsy (LB) remains the gold standard for the assessment of liver fibrosis, although it is invasive and can have complications. The present study compares several noninvasive methods of fibrosis assessment in chronic hepatitis C (CHC), including acoustic radiation force impulse (ARFI) elastography, aspartate aminotransferase:platelet ratio index (APRI), Forns, FIB-4, and King scores versus percutaneous LB. MATERIAL AND METHODS: This prospective study enrolled 51 untreated CHC patients. Biological tests necessary for the calculation of the scores (according to the classic formulas) were performed within a week of LB. The time interval between LB and tissue stiffness, assessed according to the Metavir score, was <6 months. Cutoff values were determined using area under receiver-operating characteristic curves (AUROC). RESULTS: The best test for predicting significant fibrosis (F ≥2 Metavir) was ARFI elastography with an AUROC of 0.90, followed by FIB-4 (AUROC = 0.86), King (AUROC = 0.85), Forns (AUROC = 0.84), and APRI (AUROC = 0.82). For a cutoff of 1.31 m/s, ARFI had 89.3% sensitivity (Se) and 87% specificity (Sp). The best test for predicting cirrhosis was ARFI elastography with an AUROC of 0.98, followed by FIB-4 (AUROC = 0.94), King (AUROC = 0.90), APRI (AUROC = 0.82), and Forns (AUROC = 0.81). For a cutoff of 1.95 m/s, ARFI had 100% Se and 95.2% Sp. CONCLUSION: ARFI elastography had very good accuracy for the assessment of liver fibrosis. It was more effective than APRI, Forns, King, and FIB-4 scores for the prediction of significant fibrosis and cirrhosis in CHC patients.

Use of magnetic resonance elastography to assess hepatic fibrosis in children with chronic liver disease.

Management of pediatric chronic liver disease is limited by lack of validated noninvasive biomarkers of histologic severity. We demonstrate that magnetic resonance elastography is feasible and accurate in detecting significant hepatic fibrosis in a case series of 35 children with chronic liver disease, including severely obese children.

Medición volumétrica de grasa visceral abdominal con RM y su relación con elastografía hepática en una población diabética / Volumetric measurement of abdominal visceral fat by MRI and its relation to transient elastography in a diabetic population

Background. Increase in visceral fat is associated to the development of fatty liver and liver fibrosis. Hepatic elastography is a novel noninvasive method for assessing liver fibrosis. Objective. To evaluate the relationship between visceral adipose tissue volume (VAT), subcutaneous adipose tissue volume (SAT) as measured by Magnetic Resonance Imaging (MRI) and transient elastography (TrE) values using ARFI (Acoustic Radiation Force Impulse) in type 2 Diabetic Mellitus patients (DM2). Methods. We included 20 DM2 patients (mean age: 62 years, range: 55-75, mean weight: 77.8 kg, range: 61.5-97). Patients underwent an MRI study in a Philips Intera 1.5T scanner. MR imaging protocol included a spectral excitation sequence centered on the fat peak. The sequence included 32 cross sections, 7mm thick, from the diaphragmatic cupula to the inferior border of the kidney. VAT was measured by using the semiautomatic Image J software. Each patient underwent a hepatic elastograpy (HE); 10 ARFI measurements were performed in the right hepatic lobe. Finally, a statistical analysis was performed by applying Pearson correlation between abdominal fat volumes and ARFI scores Results. Mean VAT was 2472 +/- 861 cc, (1173-4020 cc), whilst the mean ARFI was 1.62 ± 0.8 m/s, (0.8-3.4 m/s). Correlations obtained were r=0.08 between VAT and ARFI (p=0.72); 0.13 between SAT and ARFI (p=0.57), and -0.06 between (VAT+SAT) and ARFI (p=0.77). By subdividing the sample universe, we observed that the group with ARFI scores greater than 1.6 m/s (7 patients) had a correlation of 0.63 between VAT and ARFI (p=0.12); of 0.66 between SAT and ARFI (p=0.10), and of 0.94 between VAT+SAT and ARFI (p=0.001). In the subgroup with ARFI values inferior to 1.6 m/s (13 patients), the correlation was of 0.11 between VAT and ARFI (p=0.71); of 0.26 between SAT and ARFI (p=0.38), and of 0.32 between ( VAT+SAT) and ARFI (p=0.28). When adjusted for gender, ARFI scores greater than.

Introducción. La acumulación de grasa visceral se asocia al desarrollo de enfermedad hepática. La elastografía hepática es un método novedoso no invasivo para evaluar fibrosis hepática. Objetivo. Evaluar la relación entre el volumen de tejido adiposo visceral (VAT), volumen de tejido adiposo subcutáneo (SAT) medido por resonancia magnética (RM), con índices de elastografía hepática (EH) utilizando ARFI (fuerza de impulso de radiación acústica) en pacientes con Diabetes Mellitus tipo 2 (DM2). Métodos. Fueron incluidos 20 pacientes (edad promedio: 62 años, rango: 55-75 años, peso promedio: 77,8 kg, rango: 61,5-97 kg) con DM2. Los pacientes se sometieron a un examen de RM en un resonador Philips Intera 1.5T. Al protocolo de RM se agregó una secuencia de excitación espectral centrada en el peak de grasa. La secuencia incluyó 32 cortes transversales, grosor 7mm, desde la cúpula diafragmática hasta el borde inferior renal. En las imágenes se midió VAT utilizando el software Image J (freeware). En cada paciente se realizó una EH, utilizando ARFI con 10 medidas en lóbulo hepático derecho. Finalmente, se realizó un análisis estadístico a través de la correlación de Pearson entre los volúmenes de grasa abdominal y ARFI. Resultados. El promedio de VAT fue 2472 +/- 861 cc, (1173-4020 cc), el promedio de ARFI fue 1,62 ± 0,8 m/s, (0,8-3,4 m/s). Se obtuvieron correlaciones de r=-0,08 entre VAT y ARFI (p=0,72), de 0,13 entre SAT y ARFI (p=0,57), y de -0,06 entre (VAT+SAT) con ARFI (p=0,77). Subdividiendo el universo muestral, se encontró que el grupo con ARFI mayor que 1,6 m/s (7 pacientes) obtuvo una correlación de 0,63 entre VAT y ARFI (p=0,12), de 0,66 entre SAT y ARFI (p=0,10), y de 0,94 entre (VAT+SAT) con ARFI (p=0,001). En el subgrupo con ARFI inferior a 1,6 m/s (13 pacientes) la correlación fue 0,11 entre VAT y ARFI (p=0,71), de 0,26 entre SAT y ARFI (p=0,38), y de 0,32 entre (VAT+SAT) y ARFI (p=0,28).