Quantitative Acoustic Radiation Force Impulse Research Articles

Acoustic radiation force impulse elastography: a tool for muscle aging assessment: a pilot study

AbstractBackgroundCAPARFI study explored whether sonoelastographic data collected using the acoustic radiation force impulse (ARFI) system are reliable when evaluating skeletal muscles and whether the technique can detect muscle changes with aging.MethodsTwenty young (YH; 18–30 years) and 30 old (OH; ≥70 years) healthy volunteers and 15 old patients with cancer (OP; ≥70 years) were assessed through quantitative ARFI measurements (m s−1) of the relaxed rectus femoris, tibialis anterior, and soleus muscles, and Short Physical Performance Battery (SPPB) test. The reliability in ARFI measurements was evaluated by intra‐class correlation coefficient. Among‐group differences in ARFI measurements and SPPB were evaluated using a global linear model.ResultsAcoustic radiation force impulse measurements demonstrated high reliability in all groups (intra‐class correlation coefficient > 0.82). ARFI measurements of the rectus femoris muscle were significantly lower in both the OH and OP groups than in the YH group (1.46 ± 0.12 and 1.50 ± 0.32 vs. 1.80 ± 0.35 m s−1). The ARFI measurements of the soleus muscle were significantly lower in the OP group than in the YH group (1.37 ± 0.37 vs. 1.70 ± 0.53 m s−1). No significant difference was observed for tibialis anterior muscle. Significantly lower SPPB scores were observed in the OP group (10.3 ± 1.4 out of 12) than in the YH (12.0 ± 0.0) and OH groups (11.5 ± 1.0).ConclusionsThis study demonstrated that ARFI quantitative measurements are reliable in relaxed skeletal muscle and may be reliably used to explore muscle changes with aging and/or neoplasia in clinical practice.

The role of acoustic radiation force impulse imaging in the diagnosis of cervical carcinoma

Aim: To investigate the diagnostic value of acoustic radiation force impulse imaging in the detection of cervical cancer, and to assess the contribution of this imaging method in distinguishing histological subtypes of cervical carcinoma.Materials and Methods: Twenty four patients with malignant cervical mass and 25 healthy volunteers were included in this prospective study. Ultrasonographic evaluation were performed using a 3.5–6-MHz convex abdominal transducer and adequate software for performing elastographic examinations in quantitative acoustic radiation force impulse mode (Virtual Touch Quantification®). Every examination consisted of at least three independent shear wave velocity measurements. The mean shear wave velocity values were calculated, and used for statistical analysis. Postoperative pathology results of the lesions were used as the reference standard.Results: The mean shear wave velocity values were calculated as 2.79±1.03 m/s in cervical carcinomas, and as 1.86±0.62 m/s in control group. The mean shear wave velocity value of cervical carcinomas was significantly higher than the control group (p=0.003). The mean shear wave velocity values in squamous carcinoma, adenocarcinoma, and adenosquamous carcinoma subtypes were calculated as 2.78±0.93 m/s, 3.16±1.46 m/s, and 1.90±0.21 m/s, respectively. There were no significant differences between cervical carcinoma subtypes in terms of their shear wave velocity values (p=0.247).Conclusion: Acoustic radiation force impulse imaging is a non-invasive and cost-effective, promising adjunct modality that enables objective quantitative measurement, which may contribute to the diagnosis of malignant cervical masses.

Acoustic Radiation Force Impulse (ARFI) elastography imaging of equine distal forelimb flexor structures

ABSTRACT This study set out to determine normal values for acoustic radiation force impulse (ARFI) elastography of the superficial digital flexor tendon, deep digital flexor tendon, accessory ligament of the deep digital flexor tendon and suspensory ligament in horses. Twenty-four horses were submitted to conventional sonographic assessment and elastography imaging (quantitative ARFI method) of distal forelimb tendons and ligaments at nine anatomical regions. Elastograms depicted tendons and ligaments in orange to red tones consistent with greater stiffness. Shear wave velocity was higher in the longitudinal compared to the cross-sectional plane but did not differ significantly between the left and right forelimbs. The suspensory ligament was stiffer compared to remaining structures in the cross-sectional plane. Ligaments were stiffer than tendons and the deep digital flexor tendon was stiffer than the superficial digital flexor tendon in the longitudinal plane. Target structures were stiffer in male compared to female horses and stiffness tended to increase with age. ARFI elastography proved to be a feasible and reproducible imaging modality for assessment of distal forelimb tendons and ligaments in horses. Qualitative features derived from stiffness quantification in these structures can be applied to horses with musculoskeletal disorders, as well as to other animal species.

Shear wave velocity by quantitative acoustic radiation force impulse in the placenta of normal and high-risk pregnancy

BackgroundTraditionally, the placental functional integrity is suggested by indirect ultrasound measurements like fetal growth, amniotic fluid index, and uterine and umbilical artery Doppler indices. Only recently the elasticity of the placenta is studied as a measure of placental consistency and biomechanical prosperities and may reflect the placental function. Shear wave velocity is the quantitative parameter of the shear wave elastography. A high-risk pregnancy is a situation which puts the mother, the fetus, or both at greater risk than a normal pregnancy.ResultsThe shear wave velocity (SWV) showed no significant difference between the placenta of normal pregnancies in the second and third trimesters (0.85 ± 0.43 m/s and 0.89 ± 0.57 m/s, respectively). The placenta of patients with preeclampsia/eclampsia had high SWV in the second and third trimesters (2.13 ± 1.48 m/s and 2.23 ± 1.48 m/s) with a highly significant difference from the normal placenta (P < 0.001). The placentas with abnormal location (placenta previa) and penetration (placenta accreta) had higher SWV than the placenta of normal pregnancies. The mean SWV for placenta previa was 1.1 ± 0.74 m/s and 1.3 ± 0.81 m/s in the second and third trimesters, respectively, with a mildly significant difference with the normal placenta. The placenta accreta shows high mean SWV in the second and third trimesters (1.6 ± 0.65 m/s and 1.961.6 ± 0.65, respectively) which differed significantly (P < 0.001) from SWV in the normal placenta in the second and third trimesters.ConclusionShear wave velocity measurement as the quantitative parameter of acoustic radiation force impulse (ARFI) elastography reflects the placental elasticity in normal and high-risk pregnancies. The SWV increases in conditions like hypertension, preeclampsia, maternal renal disease, and diabetes and reflects the structural and biomechanical abnormalities in such diseases. High shear wave velocity correlates with the incidence of growth restriction and abnormal Doppler parameters especially in the hypertensive disease. The virtual touch quantification (VTQ) can be used as a complementary diagnostic and prognostic tool in high-risk pregnancy.

Acoustic radiation force impulse (ARFI) elastography to asses maternal and foetal structures in pregnant ewes.

The aim of this study was to evaluate the stiffness of foetal lungs, liver, kidneys and placentomes by acoustic radiation force impulse (ARFI) elastography in ovine and to correlate obtained findings with foetal development. Twenty-four ewes were included, and tissue stiffness of foetal lung, liver, kidney and placentome was measured beginning with 10th gestational week by qualitative-quantitative ARFI elastography. A total of 33 healthy lambs were born. Qualitative elastographic analysis permitted to classify maternal and foetal tissues elasticity in decreasing order as follows: placentome, kidney, liver and lung. Regarding quantitative ARFI elastography data, shear wave velocity (SWV) of foetal lung and liver varied. The lung SWV decreased gradually from the 16th to the 21st gestational week (R2 =0.80; p<0.001), while liver SWV increased gradually from the 14th to 21st gestational week (R2 =0.80; p<0.001). In contrast, the kidneys and placentomes SWV's remained constant through gestation (p=0.076; and 0.34). ARFI elastography was shown feasible for evaluation of maternal and foetal tissues stiffness in the ovine model. It can be used to demonstrate pulmonary and hepatic stiffness modifications during foetal development.

Value of different ultrasound elastography techniques in patients with venous malformations prior to and after sclerotherapy.

Comparison of different ultrasound elastography techniques for detection of changes after sclerotherapy within venous malformations. In patients with venous malformations sonography was executed at exactly the same position prior to and after ethanol-gel sclerotherapy. Both examinations included B-Mode, vascular sonography with Color-Coded Duplex Sonography, and additional sonography with different elastography techniques (strain, qualitative and quantitative Acoustic Radiation Force Impulse (ARFI) elastography) with a linear transducer (6-9 MHz). Qualitative elastograms were read in consensus and scored. Differences of elasticity scores were statistically analyzed, p-values <0.05 were regarded significant. Elasticity scores of strain and qualitative ARFI elastography in 25 patients (21 females, averagely 24.4 years old) were comparable before treatment (p = 0.69). After therapy qualitative ARFI scores changed significantly compared to pre-treatment scores (p = 0.0017), whereas strain elastography scores revealed no significant changes (p = 0.13). Quantitative ARFI values obtained after sclerotherapy within the venous malformations were significantly higher compared to pre-treatment values (p = 0.049), and significantly higher to values obtained in surrounding tissue (p = 0.030). Comparison of pre- and post-treatment ARFI values of the surrounding tissue was not significant (p = 0.67). Elasticity scores of qualitative ARFI elastography reliably detect ethanol-gel induced changes in venous malformations. Quantitative ARFI may be a tool for therapy planning, and for monitoring sclerotherapy outcome as well as the effect of sclerosing agents on malformation and surrounding tissue in patients with venous malformations.

Acoustic radiation force impulse (ARFI) elastography of adrenal glands in healthy adult dogs

ABSTRACT To describe the ARFI elastography in the evaluation of the adrenal glands in adult dogs, to evaluate the stiffness of adrenal parenchyma and to determine the qualitative and quantitative standards of the ARFI technique, which have not yet been described in veterinary medicine. Sixty adrenal glands from thirty healthy adult dogs were evaluated by B-mode and qualitative and quantitative ARFI elastography to assess the stiffness of healthy parenchyma and to determine the quality and quantity (shear velocity) standards of ARFI technique in body, cranial and caudal adrenal poles. Findings of ultrasonography evaluations were normal. Qualitative elastography showed that adrenal glands were not deformable and presented homogeneous middle-gray areas. The results of shear wave velocity were similar statically (P = 0.3087): 1) left adrenal - 1.42 m/s for cranial polar, 1.31 m/s for body region, and 1.71 m/s for caudal polar; 2) right adrenal - 1.42 m/s for cranial polar, 1.74 m/s for body region and 1.63 m/s for caudal pole. Quantitative and qualitative ARFI elastography of dogs' adrenal glands is feasible, well tolerated, easily implemented and may provide baseline data in the study of this structure to allow the use of ARFI.

Comparison of quantitative acoustic radiation force impulse imaging and 2D SWE of liver fibrosis in chronic liver disease

Comparison of quantitative acoustic radiation force impulse imaging and 2D SWE of liver fibrosis in chronic liver disease

Assessment of the Stiffness of Major Salivary Glands in Primary Sjögren's Syndrome through Quantitative Acoustic Radiation Force Impulse Imaging

The purpose of the study described here was to evaluate salivary gland stiffness in primary Sjögren's syndrome (pSS) via acoustic radiation force impulse imaging, including Virtual Touch tissue quantification (VTQ) and Virtual Touch tissue imaging quantification (VTIQ). Twenty-one patients with pSS and 11 healthy patients were included, and the paired parotid and submandibular glands of all of the patients were examined using VTQ and VTIQ. Differences between the two groups were compared with independent and paired t-tests. The VTQ value for the parotid in the pSS group was significantly higher than that obtained for the control group (1.33 ± 0.22 and 1.18 ± 0.04 m/s, respectively, p < 0.01). The VTIQ values for the parotid and submandibular gland were both significantly higher in the pSS group than in the control group (p < 0.05). In the pSS group, a positive correlation was observed between the VTQ and VTIQ results for the parotid and submandibular glands. In summary, the stiffness of the major salivary glands in patients with pSS was increased compared with that of patients with normal glands. This finding indicates that VTQ and VTIQ imaging may be valuable adjuncts to gray-scale ultrasonography for the clinical diagnosis of pSS.

A new sampling method for spleen stiffness measurement based on quantitative acoustic radiation force impulse elastography for noninvasive assessment of esophageal varices in newly diagnosed HCV-related cirrhosis.

In our study, we evaluated the feasibility of a new sampling method for splenic stiffness (SS) measurement by Quantitative Acoustic Radiation Force Impulse Elastography (Virtual Touch Tissue Quantification (VTTQ)).We measured SS in 54 patients with HCV-related cirrhosis of whom 28 with esophageal varices (EV), 27 with Chronic Hepatitis C (CHC) F1–F3, and 63 healthy controls. VTTQ-SS was significantly higher among cirrhotic patients with EV (3.37 m/s) in comparison with controls (2.19 m/s, P < 0.001), CHC patients (2.37 m/s, P < 0.001), and cirrhotic patients without EV (2.7 m/s, P < 0.001). Moreover, VTTQ-SS was significantly higher among cirrhotic patients without EV in comparison with both controls (P < 0.001) and CHC patients (P < 0.01). The optimal VTTQ-SS cut-off value for predicting EV was 3.1 m/s (AUROC = 0.96, sensitivity 96.4%, specificity 88.5%, positive predictive value 90%, negative predictive value 96%, positive likelihood ratio 8.36, and negative likelihood ratio 0.04). In conclusion, VTTQ-SS is a promising noninvasive and reliable diagnostic tool to screen cirrhotic patients for EV and reduce the need for upper gastrointestinal endoscopy. By using our cut-off value of 3.1 m/s, we would avoid endoscopy in around 45% of cirrhotic subjects, with significant time and cost savings.

Characterization of Focal Liver Lesions (FLL) with Acoustic Radiation Force Impulse (ARFI) Elastometry

The technology of acoustic radiation force impulse (ARFI) represents an innovative method for the quantification of tissue elasticity. The aim of this prospective pilot study was to evaluate the role of ARFI elastometry of focal liver lesions (FLL) and the surrounding liver parenchyma. All patients with unclear FLL in B-mode ultrasound were assigned to ARFI elastometry (m/sec). Measurement sites were located within the FLL, in the peritumoral tissue and in hepatic segment VIII (intercostal approach). Histology and CEUS served as the reference for the characterization of the lesions. A total of 81 patients were enrolled, of whom 62 patients (39 females, 23 males; mean age 54 years) had FLL measurable by means of ARFI. The lesions were: 38 benign (61 %) and 24 malignant FLL (39 %). The ARFI elastometric values of the FLL differed significantly from those of the liver parenchyma (p < 0.001). Elastometry of benign lesions and of malignant tumors showed statistically comparable results (p = 0.28). The lowest ARFI values were observed in focal fatty sparing and the highest in CCC. Only focal fatty sparing and HCC showed negative differences between FLL and peritumoral tissue or liver parenchyma. In 23 % of the hepatic lesions, no reliable quantitative ARFI results were obtainable due to false, inconsistent or technically failed measurements. FLL vary in ARFI elastometry. However, high ARFI values occur in benign as well as in malignant lesions and do not permit differentiation between them.