Ultrasound Acoustic Radiation Force Impulse Research Articles

1008-P: 3D Acoustic Radiation Force Impulse Virtual Imaging of Whole Human Abdominal Subcutaneous Tissue Imaging with “Insulin Ball”

Introduction: Current evidence suggests that subcutaneous “insulin ball”, a feature of the tissue-dystrophy, provokes hormonal perturbation in insulin absorption. Unforeseen 3-dimension (3D) whole human abdominal subcutaneous tissue within the insulin injecting subjects, we tried to elucidate a novel 3D ultrasound acoustic radiation force impulse (3D-ARFI) to quantitates the entire “tissue-dystrophy” volume in human. Methods: Seven patients with daily insulin injected diabetes were enrolled and the 3D-ARFI was applied to measure tissue displacement. To generate the elasticity gradients along the depth axis of the whole abdominal subcutaneous tissue, we compared lateral region of the abdomen as internal-control. A subcutaneous insulin tolerance test was conducted to validate the rate of insulin absorption at the site of the tissue-dystrophyand control. We also analyzed the volume of whole insulin induced tissue-dystrophy with entire abdominal wall volume governed by consecutive ARFI slice imaging. Results: Subcutaneous tissue stiffness measured by ARFI revealed that ARFI enabled the elastic characterization (p<.01). The 3D-ARFI demonstrated the differentiated elastic layers in the 3D model of entire human abdominal wall, and calculatedthe 3D volume of the tissue-dystrophy from entire abdominal subcutaneous volume (2.59±1.20%). The serum concentration area-under the curve (0-240min) after the 0.1U/kg IAsp injection was 33% lower at the tissue-dystrophylesions compared to the control lesion (p<.05). Conclusion: We present the first example of virtual touch quantification imaging with the 3D-ARFI of human abdominal subcutaneous tissue, focusing on insulin injected diabetes and demonstrate its application for the biomedical 3D structure. Disclosure G. Sato: None. H. Uchino: None. Y. Shimizu: None. K. Ishii: None. A. Ishiko: None. T. Morita: None. N. Kumashiro: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc. Speaker’s Bureau; Self; Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd., Takeda Pharmaceutical Company Limited. T. Hirose: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo, Mitsubishi Tanabe Pharma Corporation, Ono Pharmaceutical Co., Ltd., Takeda Pharmaceutical Company Limited. Speaker’s Bureau; Self; AstraZeneca, Lilly Diabetes, Novo Nordisk Inc., Sanofi, Sumitomo Dainippon Pharma Co., Ltd. Funding Japan Society for the Promotion of Science (17K01425)

Role of Ultrasound Acoustic Radiation Force Impulse in Differentiating Benign from Malignant Superficial Lymph Nodes.

Objective:The purpose of this study was to evaluate the diagnostic performance of acoustic radiation force impulse (ARFI) imaging in differentiating benign from malignant peripheral lymphadenopathy.Materials and Methods:This was a prospective study approved by the Institutional Review Board with financial grant for the same. Ultrasound and ARFI imaging of peripheral lymph nodes were performed and correlated with pathological results, which were used as the reference standard. The virtual touch tissue imaging and virtual touch tissue quantification parameters of ARFI were analyzed in 86 lymph nodes, of which 78 were included in the study. Using receiver operating characteristic curve analysis, the diagnostic usefulness of ARFI values were evaluated with respect to their sensitivity, specificity, and area under the curve.Results:The mean area ratio of benign lymph nodes was 0.88 (±0.2) and that of malignant lymph nodes was 1.17 (±0.14). The mean shear wave velocities (SWV) of benign and malignant lymph nodes were 2.02 m/s (±0.94) and 3.7 m/s (±2.27), respectively. The sensitivity and specificity of virtual touch imaging area ratio in differentiating benign from malignant lymph nodes was 97% and 77%, of SWV was 71% and 70%, and of SWV ratio was 68% and 79%, respectively.Conclusion:As ARFI was found to have a superior diagnostic performance over conventional ultrasound and color Doppler in the characterization of lymph nodes, we recommend its routine use in differentiating benign from malignant nodes.

Ultrasound Acoustic Radiation Force Impulse imaging for High Intensity Focused Ultrasound focal spot localization.

Focal spot precise localization highly contributes to the accuracy and safety of High Intensity Focused Ultrasound (HIFU) therapies, and it is usually performed by means of Magnetic Resonance-Acoustic Radiation Force Impulse imaging (MR-ARFI). Acoustic Radiation Force Impulse imaging using ultrasound (US-ARFI) is herein proposed as a valid alternative to MR-ARFI for an accurate and non-destructive detection of the focal spot position during the pre-treatment phase. To this aim, a system composed of a HIFU transducer for generating the acoustic radiation force and a 2D confocal ultrasound probe for measuring the induced micro-displacement have been used. Then, an algorithm based on the Normalized Cross Correlation was implemented for the creation of a displacement map in which the highest displacement area, corresponding to the focal spot region, is unequivocally visualized. The feasibility of the proposed USARFI method for HIFU focal spot localization was successfully demonstrated in a tissue mimicking phantom model.

Correlation of Ultrasound Acoustic Radiation Force Impulse Elastography with Sonographic Severity Grading of Fatty Liver Disease

Correlation of Ultrasound Acoustic Radiation Force Impulse Elastography with Sonographic Severity Grading of Fatty Liver Disease

Virtual Analysis of Pancreatic Cystic Lesion Fluid Content by Ultrasound Acoustic Radiation Force Impulse Quantification

The purpose of this study was to prospectively evaluate the application of acoustic radiation force impulse (ARFI) imaging implemented with Virtual Touch tissue quantification (Siemens AG, Erlangen, Germany) in the study of pancreatic cystic lesions by using different analysis methods compared with the final diagnosis (pathologic or by magnetic resonance imaging and endoscopic sonographic findings). Thirty-eight patients with pancreatic cystic focal lesions (diameter >3 cm and located at a depth of 5.5 cm) were included in the study and underwent conventional sonography. For every patient, 5 measurements in the Virtual Touch tissue quantification region of interest were obtained. To distinguish mucinous (potentially malignant) from serous (mainly benign) cystic lesions, the result XXXX/0 was considered to mean simple liquids (comparable to water), and the accuracy of Virtual Touch tissue quantification in differentiating pancreatic cystic lesions was calculated. To consider a lesion as containing complex fluids (potentially mucinous), two different reading methods were applied: (1) at least 2 numerical values when obtaining 5 measurements; and (2) the prevalence of numerical values irrespective of the number of measurements. The sensitivity, specificity, positive and negative predictive values, and accuracy were calculated for the differential diagnosis between mucinous and nonmucinous cystic lesions. By the first reading method, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in the group of cystic lesions were 68.8%, 77.3%, 68.8%, 77.3%, and 73.7%, respectively; by the second method, the values were 37.5%, 100%, 100%, 68.8%, and 73.3%. Acoustic radiation force impulse imaging with Virtual Touch tissue quantification can have a role in the noninvasive characterization of pancreatic cystic lesions during conventional sonographic examinations.

Acoustic radiation force impulse (ARFI) imaging with Virtual Touch Tissue Quantification in liver disease associated with cystic fibrosis in children

Cystic-fibrosis-associated liver disease (CFLD) may lead to portal hypertension (PHT) and cirrhosis. Clinical signs and biochemistry of liver involvement are not discriminating. The aim of the study was to evaluate the performance of acoustic radiation force impulse (ARFI) with virtual tissue quantification in comparison with clinical signs, biochemistry and standard hepatic ultrasound (US) patterns. Virtual Touch Tissue Quantification, an implementation of US ARFI with shear-wave velocity (SWV) measurements was used in 75 children with cystic fibrosis (CF) and suspected CFLD to quantify hepatic stiffness. In each patient, ten measurements of SWV were performed on the right hepatic lobe. Patients were also evaluated by standard diagnostic tools (standard US, liver- and lung function tests, oesophagogastroscopy). Among CF patients, median SWV was significantly higher in patients with clinical, biochemical and US signs of hepatic involvement than in patients without US evidence of liver disease 1.08 m/s [(95% confidence interval (CI), 1.02-1.14]. Median SWV values in patients with portal hypertension, splenomegaly and oesophageal varices were 1.30 (95% CI, 1.17-1.43), 1.54 (95% CI, 1.32-1.75) and 1.63 (95% CI, 1.26-1.99), respectively. Differences were significant (p<0.001). ARFI is an innovative screening technique able to help identify CFLD in children.

Temporal changes in the stiffness of the remnant liver and spleen after donor hepatectomy as assessed by acoustic radiation force impulse: A preliminary study

Virtual touch tissue quantification (VTTQ) is an implementation of ultrasound acoustic radiation force impulse imaging that provides numerical measurements of tissue stiffness. We have evaluated the temporal changes of the remnant liver and spleen after living donor hepatectomy with special reference to the differences between right and left liver donation. Nineteen living donors who received right lobectomy (small remnant liver [SRL] group; n = 7) or extended left and caudate lobectomy (large remnant liver [LRL] group; n = 12) were enrolled. They underwent measurement of liver and spleen VTTQ before and after donor surgery. Virtual touch tissue quantification of the remnant liver increased postoperatively until postoperative day (POD) 3-5, and the values in the SRL group were significantly higher than those in the LRL group at POD 3-9. The values of the spleen also increased after donor surgery and the values in the SRL group were significantly higher than those in the LRL group at POD 3-14. A significant positive correlation between postoperative maximum value of VTTQ and postoperative maximum total bilirubin levels was observed. In liver transplant recipients, there was a significant positive correlation between preoperative spleen VTTQ and the corresponding actual portal venous pressure that was measured at the time of transplant surgery. Stiffness of the remaining liver and spleen in the smaller remnant liver group became harder than that in the larger remnant liver group. Perioperative measurement of liver and spleen VTTQ seems to be a useful means for assessing the physiology of liver regeneration.

Pancreatic Mucinous Cystadenoma at Ultrasound Acoustic Radiation Force Impulse (ARFI) Imaging

Pancreatic Mucinous Cystadenoma at Ultrasound Acoustic Radiation Force Impulse (ARFI) Imaging

Acoustic Radiation Force Impulse (ARFI) technique in ultrasound with Virtual Touch tissue quantification of the upper abdomen

Virtual Touch tissue quantification is an implementation of ultrasound (US) Acoustic Radiation Force Impulse (ARFI) imaging that provides numerical measurements (wave-velocity values) of tissue stiffness. The aim of this study was to define the normal values of shear-wave speed for the healthy liver, gallbladder, pancreas, spleen and kidneys. Thirty-five young healthy volunteers underwent Virtual Touch tissue quantification after having signed an informed consent form. All upper abdominal organs were examined by two independent operators. A phantom fluid model was also evaluated. All mean wave-velocity values were analysed and compared. Results. One hundred and forty measurements of liver, pancreas, spleen and kidneys, and 70 measurements of the gallbladder lumen were performed. Twenty measurements on the phantom were also performed. Comparing all measurements separately made by each operator in different parts of the organs, no statistically significant differences were observed. A "XXXX/0" value was always obtained from all measurements performed on the gallbladder lumen and on the phantom fluid model. Liver, pancreas, spleen and kidney mean values were 1.59 m/s, 1.40 m/s, 2.44 m/s and 2.24 m/s, respectively. Virtual Touch tissue quantification is a new, promising implementation of the US ARFI technique, which provides numerical measurements of tissue stiffness. The mean shear-wave speed is lower in the pancreatic parenchyma than in the liver and kidney, whereas the spleen is characterised by the highest mean value. In simple fluids such as water, the value identified by the system with "XXXX" or 0, is always measured.