Role of acoustic radiation force impulse elastography of placenta in the diagnosis of pre-eclampsia.

BACKGROUND: Placental dysfunction is one of the main causes of preeclampsia and hypertensive disorders of pregnancy. MATERIAL AND METHODS: This is a prospective comparative study done on 30 pregnant women with pre-eclampsia and another 30 pregnant women as controls. In all these subjects the elasticity of the placenta was measured. RESULTS: The results obtained showed that there was a significant difference in SWV values between the two groups (p value = 0.001). The mean SWV value of normal pregnant women was 0.99 m/ second as opposed to 1.99 m/second in pre-eclamptic pregnant women. CONCLUSION: Sonoelastography is a promising noninvasive tool in the detection of preeclampsia with high diagnostic accuracy. The SWV values measured at the central zones of the placenta with a cut-off value of 1.325 m/s identify the presence of pre-eclampsia with high sensitivity and specificity.

Clinical and diagnostic characteristics of non-alcoholic fatty liver disease among Egyptian children and adolescents with type1 diabetes.

BACKGROUND: Type 1 diabetes mellitus (T1DM) patients are at an increased risk for non-alcoholic fatty liver disease (NAFLD). This study aimed to evaluate the clinical criteria associated with the diagnosis of Non-Alcoholic Fatty Liver Disease (NAFLD) among T1DM Egyptian children and adolescents. METHODS: 74 T1DM patients aged 8-18 year were enrolled in this cross sectional study. Assessments of Clinical status, anthropometric measures, lipid profile, glycated haemoglobin (HbA1c) and liver enzymes were done. Abdominal Ultrasound evaluation of hepatic steatosis was done. Accordingly, patients were divided into two groups (NAFLD and normal liver group) and compared together. Assessment of liver fibrosis using acoustic radiation force impulse elastography (ARFI) was done. Statistical analysis included; independent t-test, Chi square and Fisher's Exact, Pearson and Spearman tests and Logistic regression models for factors associated with fatty liver were used when appropriate. RESULTS: In this study; 74 patients were enrolled; 37 males (50%) and 37 females with mean age 14.3 ± 3.0 year. The mean insulin dose was 1.1 ± 0.4 U/kg and mean disease duration was 6.3 ± 3.0 year. NAFLD was detected in 46 cases while 28 cases had normal liver as diagnosed by abdominal ultrasound. Cases with NAFLD had statistically significant higher BMI-Z scores, waist/hip, waist/height and sum of skin fold thicknesses compared to those with normal liver (P < 0.05). The mean value of HbA1c % was significantly higher in NAFLD group (P = 0.003). Total cholesterol, triglycerides and LDL serum levels were significantly elevated (p < 0.05), while the HDL level was significantly lower in NAFLD cases (p = 0.001). Although, serum levels of liver enzymes; ALT and AST were significantly higher among cases with NAFLD than in normal liver group (p < 0.05), their means were within normal. Using the ARFI elastography; NAFLD cases exhibited significant fibrosis (F2, 3 and 4). BMI, patient age and female gender were among risk factors for NAFLD. CONCLUSIONS: NAFLD represents a serious consequence in type 1 diabetic children and adolescents that deserves attention especially with poor glycemic control. NAFLD has the potential to evolve to fibrosis. This study demonstrated a very high prevalence of NAFLD in T1D children and adolescents using US which was (62.2%) with the percent of liver fibrosis among the NAFLD cases (F2-F4) using ARFI elastography was 26%. BMI, age of patients and female gender were detected as risk factors for NAFLD.

Post-hepatoportoenterostomy Acoustic Radiation Force Impulse Elastography to Predict Two-year Outcome of Biliary Atresia.

Background and Aims: Early identification of prognostic factors to predict transplant/death outcome of biliary atresia (BA) is challenging. We aimed to investigate the longitudinal changes and predictive value of dynamic changes in acoustic radiation force impulse elastography with shear wave speed (SWS) quantification and other parameters within three months after hepatoportoenterostomy (HPE) for 2-year BA outcomes. Methods: Seventy-four patients who underwent HPE between July 2016 and June 2019 were prospectively enrolled. Outcomes were classified into native liver survival and transplant/death groups. Acoustic radiation force impulse elastography was performed sequentially at 3 months intervals post-HPE. Cox regression analysis was used to determine the superior SWS values and other predictors of liver transplantation or death. Results: Among patients 2 years of age, 36 survived with a native liver, nine died, and 29 underwent liver transplantation. The trend in SWS levels in the transplant/death group was significantly different from that in the native liver survival group. ΔSWS at 1-3 months post-HPE and total bilirubin at 1 month post-HPE were selected as superior predictors of liver transplantation or death using multivariate Cox regression models: hazard ratio (HR)=1.927; 95% confidence interval (CI): 1.475-2.661; p<0.001 and HR=1.010; 95% CI: 1.003-1.017; p=0.007, respectively. The combination of the selected ΔSWS and total bilirubin had good predictive power, with an area under the receiver operating characteristics curve of 0.89, specificity 94.44% and sensitivity 73.68%. Conclusions: Our results suggest that early postoperative bilirubin levels and SWS changes were reliable predictors of 2-year BA outcomes.

Evaluation of carotid artery stiffness in patients with coronary artery disease using acoustic radiation force impulse elastography.

OBJECTIVES: We evaluated carotid artery stiffness in patients with coronary artery disease (CAD) using acoustic radiation force impulse (ARFI) elastography and investigated the relationship between stiffness and CAD. METHODS: This study examined 76 CAD patients (aged 60.7 ± 11) and 70 healthy individuals (aged 59.6 ± 9). The left common carotid artery mean shear wave velocity (LCmeanSWV) and the right common carotid artery mean shear wave velocity (RCmeanSWV) of the anterior walls were measured using ARFI elastography, and the results of the patient group and the healthy group were compared. The common carotid intima-media thickness (CIMT) was measured in both groups and compared with mean SWV. RESULTS: The RCmeanSWVs in the patient and healthy groups were 3.47 ± 1 m/s and 2.69 ± 0.90 m/s, respectively (p < 0.001). The LCmeanSWVs in the patient and healthy groups were 3.60 ± 0.9 m/s and 2.90 ± 0.80 m/s, respectively (p < 0.001). A significant correlation was found between the RCmeanSWV and the right CIMT values and between the LCmeanSWV and the left CIMT values (r = 0.231, p = 0.03 and r = 0.331, p = 0.002, respectively). CONCLUSIONS: The mean SWV values of carotid arteries of CAD patients measured with ARFI elastography were significantly higher than the mean SWV values of the carotid arteries of healthy individuals. Thus, measurement of the carotid artery SWV could be a potential tool in the risk evaluation of cardiovascular disease. Nonetheless, new studies are required to determine whether this method serves as a useful additional tool.

Diagnostic Performance of Point Shear Wave Elastography Using Acoustic Radiation Force Impulse Technology in Peripheral Pulmonary Consolidations: A Feasibility Study.

The aim of the study described here was to evaluate the diagnostic performance of lung ultrasound point shear wave elastography using acoustic radiation force impulse (ARFI) in peripheral pulmonary consolidations (PPCs). A total of 87 patients with PPCs diagnosed from April to December 2020 were included retrospectively in the study. The inclusion criteria were (i) a PPC >1 cm; (ii) valid ARFI measurements; and (iii) confirmation of the diagnosis of a PPC by histocytological examination and/or clinical and radiological follow-up. The presence of pleural effusions and mean ARFI velocities (MAVs) of PPCs were evaluated. To examine the MAV for potential cutoff values between benign and malignant PPCs, a receiver operating characteristic analysis was implemented. In total, 48 of 87 PPCs (55.2%) were accompanied by pleural effusions. Benign PPCs had significantly lower MAVs than malignant PPCs (1.82 ± 0.97 m/s vs. 3.05 ± 0.73 m/s, p < 0.001). Selecting 2.21 m/s as a cutoff value yielded a sensitivity and specificity of 89.7% and 75.9%, respectively, in diagnosing malignant PPCs (area under the curve = 0.852, 95% confidence interval: 0.773-0.931). In summary, ARFI elastography may be an additional non-invasive tool for differentiating benign from malignant PPCs. Furthermore, the feasibility of using ARFI elastography in PPCs associated with pleural effusions was proved. However, there is some degree of overlap between different disease entities, and diagnosis should always take into account the clinical background.

Microstructural breast tissue characterization: A head-to-head comparison of Diffusion Weighted Imaging and Acoustic Radiation Force Impulse elastography with clinical implications.

PURPOSE: Head-to-head comparison of Diffusion Weighted Imaging (DWI) and Acoustic Radiation Force Impulse (ARFI) elastography regarding the characterization of breast lesions in an assessment setting. METHOD: Patients undergoing an ultrasound examination including ARFI and an MRI protocol including DWI for the characterization of a BI-RADS 3-5 breast lesion between 06/2013 and 10/2016 were eligible for inclusion in this retrospective, IRB-approved study. 60 patients (30-84 years, median 50) with a median lesion size of 16 mm (range 5-55 mm) were included. The maximum shear wave velocity (SWVmax) and mean apparent diffusion coefficient (ADCmean) for each lesion were retrospectively evaluated by a radiologist experienced in the technique. Histology was the reference standard. Diagnostic performances of ARFI and DWI were assessed using ROC curve analysis. Spearman's rank correlation coefficient and multivariate logistic regression were used to investigate the independence of both tests regarding their diagnostic information to distinguish benign from malignant lesions. RESULTS: Corresponding areas under the ROC curve for differentiation of benign (n = 16) and malignant (n = 49) lesions were 0.822 (ARFI) and 0.871 (DWI, p-value = 0.48). SWVmax and ADCmean values showed a significant negative correlation (ρ = -0.501, p-value < 0.001). In multivariate analysis, combination of ARFI and DWI did not improve the results of each single modality, thus no significant independent diagnostic information was present. CONCLUSION: Significant correlation between quantitative findings of ARFI and DWI in breast lesions exists. Thus, ARFI provides similar diagnostic information as a DWI-including protocol of an additional "problem-solving" MRI for the characterization of a sonographically evident breast lesion, improving the immediate patient management in the assessment setting.

Acoustic radiation force impulse elastography of liver as a screening tool for liver fibrosis in alcoholic liver disease.

CONTEXT: Acoustic radiation force impulse (ARFI) elastography is a noninvasive and quantitative technique for diagnosis of liver fibrosis. To the best of our knowledge, there are only two studies reported in literature for evaluation of alcoholic liver disease using ARFI. AIMS: The aim of this study was to evaluate the diagnostic performance of ARFI elastography for assessing liver fibrosis in alcoholic liver disease and compare it with biochemical indices aspartate transaminase-to-platelet ratio index (APRI) and fibrosis-4 Index (FIB-4) using histopathology as the reference standard. SETTINGS AND DESIGN: Institutional cross-sectional study. METHODS AND MATERIALS: The patients visiting our hospital over a period of 2 years with a high-risk consumption of alcohol (>40 g/day for men and >20 g/day for women for a cumulative period of more than 5 years) were subjected to ARFI elastography of liver, Liver Function Tests (to calculate APRI and FIB-4 indices), and liver biopsy. STATISTICAL ANALYSIS USED: Area under the receiver operating characteristic (AUROC) curve analysis, Kruskal--Wallis test for ANOVA. RESULTS: A total of 50 patients of chronic alcoholic liver disease were evaluated with ARFI elastography, which performed better than the biochemical indices in distinguishing cirrhosis of the liver (F = 4) from the severe fibrosis (F ≥ 3) with area under the receiver operating characteristic of 0.97, whereas for significant fibrosis (F ≥ 2) and severe fibrosis (F ≥ 3), it was comparable to the biochemical indices with AUROC of 0.65 and 0.70. In our study, the median shear wave velocity cutoff values were 1.37 m/s, 1.51 m/s, and 1.87 m/s for F ≥ 2, F ≥ 3, and F = 4 fibrosis stages, respectively. CONCLUSIONS: ARFI elastography is a noninvasive, reliable, and repeatable diagnostic test for grading of liver fibrosis. It performs better than the biochemical indices to differentiate severe fibrosis and cirrhosis of liver.

Quantification of Pediatric Burn Scar Stiffness Using Acoustic Radiation Force Impulse Ultrasound Elastography.

The purpose of this study was to quantify the stiffness of hypertrophic scars using acoustic radiation force impulse ultrasound elastography. Sixteen pediatric patients with hypertrophic scars resulting from burn injuries participated in this study (mean age: 5.13, standard deviation: 3.20). Values for the elastic modulus (E) of scar and control sites were obtained. Scarred areas were found to be almost four times stiffer than control sites (scar Emean = 39.29 kPa compared with control Emean = 10.19 kPa) (p = 0.0004). Correlations between scar stiffness and clinician-reported subjective scar scale scores were not observed (rs = 0.30, p = 0.27 and rs = 0.25, p = 0.35 respectively). We found that acoustic radiation force impulse imaging can discriminate between hypertrophic scars and normal skin and should be considered a potentially valuable tool in the armamentarium of objective scar measures. Future research should focus on evaluating the technology's ability to detect scar change over time in order to determine responsiveness to treatment.

[Value of contrast - enhanced ultrasonography and acoustic radiation force impulse elastography in identification of boundary range and viability of hepatic alveolar echinococcosis].

OBJECTIVE: To investigate the biologic viability and boundary range of hepatic alveolar echinococcosis (HAE) by the contrast-enhanced ultrasonography (CEUS) and acoustic radiation force impulse elastography (ARFI). METHODS: Totally 27 HAE patients confirmed by pathology underwent CEUS and ARFI examinations. RESULTS: Gray scale sonography of HAE showed unclear boundary, inhomogeneous, and middle hyperechoic nodules, and the maximum area was (6.08 ± 4.47) cm2 in 27 lesions. CEUS of HAE showed non-enhancement in three phases and black hole sign. Circumferential enhancement on the pe riphery of the lesion was synchronized with the liver parenchyma and showed "fast in and slow out". The maximum area was (8.87 ± 4.83) cm2. The area of ECUS was larger than gray scale sonography in HAE (t = 2.20, P = 0.03). The mean shear wave velocities (SWVs) of the interior, the boundary range, and the surrounding liver tissues of HAE were statistically different by ARFI (F = 84.538, P < 0.001), and the interior had the highest values. CONCLUSIONS: CEUS and ARFI examinations can detect the biologic viability and boundary range of migrating zone around HAE, which is valuable for guiding treatment, judging curative effect, and predicting prognosis.

Acoustic Radiation Force Impulse Imaging With Virtual Touch Tissue Quantification Enables Characterization of Mild Hypoxic-Ischemic Brain Damage in Neonatal Rats.

OBJECTIVES: The aim of this study was to investigate whether the measurement of brain tissue stiffness using acoustic radiation force impulse (ARFI) elastography with virtual touch tissue quantification can improve the early detection of neonatal hypoxic-ischemic brain damage in rats. METHODS: Seven-day-old Sprague-Dawley rats were randomly assigned to 3 groups: the mild asphyxia (n = 30), moderate asphyxia (n = 30), and sham control (n = 10) groups. Rats in the mild and moderate asphyxia groups were exposed to 8% oxygen (hypoxia) for 30 and 60 minutes, respectively, at 1 hour after ligation of the right common carotid artery. An ultrasound diagnostic instrument was used to obtain 2-dimensional ultrasound images, and ARFI with virtual touch tissue quantification was used to measure shear wave velocity preoperatively and at 12, 24, 48, and 72 hours postoperatively. Hematoxylin-eosin staining was used to evaluate brain damage. RESULTS: Two-dimensional ultrasound imaging detected swelling and increased echogenicity at 48 to 72 hours in the mild asphyxia group and at 24 to 72 hours in the moderate asphyxia group. The shear wave velocity substantially increased from 0.65 ± 0.04 m/s preoperatively to 0.78 ± 0.07 m/s at 72 hours in the moderate asphyxia group and from 0.64 ± 0.04 m/s preoperatively to 0.70 ± 0.03 m/s at 72 hours in the mild asphyxia group. The changes in the shear wave velocity coincided with the histopathologic changes in the brain, which included neuronal demyelination, hyperplasia, and necrosis; edema around vascular structures; and hemorrhage in the ependymal and periventricular areas. CONCLUSION: Shear wave velocity data obtained with the virtual touch tissue quantification technique may be used for early diagnosis of neonatal hypoxic-ischemic brain damage.

Value of contrast - enhanced ultrasonography and acoustic radiation force impulse elastography in identification of boundary range and viability of hepatic alveolar echinococcosis / 中国血吸虫病防治杂志

Objective To investigate the biologic viability and boundary range of hepatic alveolar echinococcosis (HAE) by the contrast-enhanced ultrasonography (CEUS) and acoustic radiation force impulse elastography (ARFI). Methods Totally 27 HAE patients confirmed by pathology underwent CEUS and ARFI examinations. Results Gray scale sonography of HAE showed unclear boundary, inhomogeneous, and middle hyperechoic nodules, and the maximum area was (6.08 ± 4.47) cm2 in 27 lesions. CEUS of HAE showed non-enhancement in three phases and black hole sign. Circumferential enhancement on the pe riphery of the lesion was synchronized with the liver parenchyma and showed “fast in and slow out”. The maximum area was (8.87 ± 4.83) cm2. The area of ECUS was larger than gray scale sonography in HAE (t = 2.20, P = 0.03). The mean shear wave velocities (SWVs) of the interior, the boundary range, and the surrounding liver tissues of HAE were statistically different by ARFI (F = 84.538, P < 0.001), and the interior had the highest values. Conclusions CEUS and ARFI examinations can detect the biologic viability and boundary range of migrating zone around HAE, which is valuable for guiding treatment, judging curative effect, and predicting prognosis.

Acoustic radiation force impulse (ARFI) elastography in a cohort of alpha-1 antitrypsin-deficient individuals and healthy volunteers.

BACKGROUND: Acoustic radiation force impulse (ARFI) elastography has been used to assess liver stiffness non-invasively. However, its usefulness in alpha-1 antitripsin-deficient (AATD) individuals is unknown. PURPOSE: To assess if liver fibrosis is present in a cohort of AATD individuals using ARFI elastography. MATERIAL AND METHODS: Eighty-three participants aged 38-39 years, except for two who were aged 40 years, underwent ultrasound elastography of the liver with ARFI technique. Twenty-nine were homozygote ZZ genotype, PiZZ (14 men, 15 women); 12 were SZ genotype, Pi SZ (8 men, 4 women), and 42 were healthy volunteers, PiMM (16 men, 26 women). Three specific liver anatomical regions were examined: segments 2/3 (left lobe) in the subcostal plane, and 5/6 and 7/8 (right lobe) in the intercostal space. In each region, three measurements were registered. RESULTS: There was no statistically significant difference between ARFI-median in the AATD group and the control group (P value = 0.877) and neither between AATD groups (PiZZ and PiSZ) with a P value = 0.259. The ARFI-median was lower in the right liver lobe than in the left lobe in all groups and the difference between both lobes was statistically significant (P = 0.001). No statistically significant difference was found in ARFI-median of the right liver lobe between the AATD group and the control group (P = 0.759), nor between the AATD group (P = 0.384). No gender difference was found in ARFI-median. CONCLUSIONS: ARFI values in AATD individuals aged 38-39 years showed no difference compare to healthy participants.

Improvement of liver stiffness measurement, acoustic radiation force impulse measurements, and noninvasive fibrosis markers after direct-acting antivirals for hepatitis C virus G4 recurrence post living donor liver transplantation: Egyptian cohort.

Progression of recurrent hepatitis C is accelerated in liver transplant (LT) recipients. Direct-acting antivirals (DAAs) have recently emerged as a promising therapeutic regimen for the treatment of hepatitis C virus infection. Rates of sustained virological response (SVR) have drastically improved since the introduction of DAAs. The aim is to elucidate the changes in liver stiffness measurement (LSM) by transient elastography (TE) as well as acoustic radiation force impulse (ARFI) elastography and fibrosis scores after DAA treatment in LT recipients with hepatitis C virus recurrence. A single-center, prospective study including 58 LT recipients with hepatitis C recurrence who received different sofosbuvir-based treatment regimens. Transient elastography and ARFI elastography values were recorded as well as fibrosis 4 score (FIB-4) and aspartate aminotransferase-to-platelet ratio index were calculated at baseline and SVR at week 24 (SVR24). The outcome was improvement in LSM and at least a 20% decrease in LSM at SVR24 compared with baseline. The sustained virological response was 98.1%. There was improvement of platelet counts, alanine aminotransferase, and aspartate aminotransferase, which in turn caused improvement in fibrosis scores at SVR24. LSM by TE and ARFI elastography decreased from the baseline median value of 6.3 kPa (interquartile range [IQR]; 4.6 to 8.8 kPa) and 1.28 m/s (IQR; 1.07 to 1.53 m/s) to an SVR24 median value of 6.2 kPa (IQR; 4.85 to 8.9 kPa) and 1.12 (IQR; 0.97 to 1.30 m/s), respectively. Logistic regression analysis showed that baseline viral load was the only significant predictor of improvement in LS after DAA therapy at SVR24. Sofosbuvir-based treatment resulted in an early improvement in parameters of liver fibrosis in post-LT patients with hepatitis C recurrence.

Shear wave velocity of the healthy thyroid gland in children with acoustic radiation force impulse elastography.

PURPOSE: Acoustic radiation force impulse imaging is a kind of shear wave elastography that can be used in children for differentiating thyroid pathologies. Possible changes in the healthy thyroid gland in children may create difficulties in the use of shear wave velocities (SWV) in thyroid pathologies. The aim of this study was to define the normal values of SWV for the healthy thyroid gland in children, elucidate the correlation of the SWV values with potential influencing factors, and evaluate intra-operator reproducibility of the SWV. METHODS: Between January 2015 and December 2015, a total of 145 healthy children (81 girls, 64 boys; mean age, 10.5 ± 3.14 years; range 6-17 years) were enrolled in the study. The SWV and volume of the thyroid gland were determined. RESULTS: The mean shear wave velocity of the thyroid gland was 1.22 ± 0.20 m/s. There was no correlation between age and the mean SWV of the thyroid gland (Spearman Rho = 0.049, p = 0.556). There was also no correlation between the thyroid gland volume or BSA and the mean SWV. The only correlation detected was between BSA and total thyroid gland volume (p < 0.001). CONCLUSION: In the present study, the SWV of the healthy thyroid gland in children was determined. There was no correlation between the SWV of the thyroid gland and age, BSA, or thyroid gland volume.

Liver stiffness reduction correlates with histological characteristics of hepatitis C patients with sustained virological response.

BACKGROUND & AIMS: We investigated the correlation between histological characteristics and changes in liver stiffness (LS) in patients with sustained virological response (SVR) using acoustic radiation force impulse (ARFI) elastography. METHODS: In this prospective study, we enrolled 176 hepatitis C patients with SVR who underwent ARFI elastography and liver biopsy before antiviral treatment, and serial ARFI elastography at the end of treatment (EOT) and at 24 weeks after the EOT. To compare the long-term changes in LS in patients with SVR using ARFI elastography, another group of 140 patients who had undergone paired biopsy after achieving SVR was included. RESULTS: Mean LS values were 1.60±0.63 m/s, 1.48±0.56 m/s and 1.37±0.62 m/s at baseline, EOT and 24 weeks after EOT, respectively, P<.001. Higher inflammatory activity at baseline was associated with an improvement in LS at the EOT, with an odds ratio of 1.940. Significant fibrosis at baseline was associated with an improvement in LS at 24 weeks after the EOT, with an odds ratio of 2.617. Among patients in the paired biopsy group with baseline fibrosis stage identical to the ARFI group, LS values at 24 weeks after the EOT did not show any difference with values at 5 years after EOT. CONCLUSIONS: Pre-treatment histological characteristics influence LS reduction after SVR is achieved.

Prevent Pancreatic Fistula after Pancreatoduodenectomy: Possible Role of Ultrasound Elastography.

BACKGROUND: The purpose of the study is to evaluate the utility of acoustic radiation force impulse (ARFI) on pancreatic tissue as a preoperative predictor of postoperative pancreatic fistula (POPF). Studied patients underwent exclusively to pancreaticoduodenectomy (PD) surgery. METHODS: Shear wave velocity of pancreas was measured using ARFI in 71 patients scheduled for PD. An intraoperative pancreas palpation was made by surgeons. A postoperative clinical evaluation to detect occurrence of POPF was performed. Sensitivity, specificity, positive and negative predictive values together with the accuracy of the method were investigated. RESULTS: Incidence of fistula observed in 17 patients with soft pancreas was approximately 53% vs. 47% without fistula. Percentage of patients without fistula was higher (66%) among 24 patients with medium parenchymal texture values, and was even higher (69%) in 26 patients with hard pancreas. Comparing ARFI and intraoperative pancreatic palpation, low wave velocity values (≤1.40 m/s) match 60% with soft parenchyma assessed by palpation and high values (>2 m/s) match 59% with hard pancreas on palpation. CONCLUSIONS: This study shows that ARFI elastography may be clinically useful as a preoperative predictor of pancreatic fistula following PD.

Noninvasive assessment of hepatic sinusoidal obstructive syndrome using acoustic radiation force impulse elastography imaging: A proof-of-concept study in rat models.

OBJECTIVES: To determine the feasibility of acoustic radiation force impulse (ARFI) elastography in the evaluation of hepatic sinusoidal obstruction syndrome (SOS) in rat models. METHODS: Rat SOS models of various severities were created by monocrotaline gavage (n = 40) or by intraperitoneal injection of 5-fluorouracil, leucovorin and oxaliplatin (FOLFOX) (n = 16). Liver shear-wave velocity (SWV) was measured using ARFI elastography. Liver samples were analysed for the SOS score, steatosis, lobular inflammation and fibrosis. RESULTS: The liver SWV was significantly elevated in the SOS models (1.29-2.24 m/s) compared with that of the matched control rats (1.01-1.09; p≤.09; veFor seven FOLFOX-treated rats which were longitudinally followed-up, the liver SWV significantly increased at 7 weeks (1.32±0.13 m/s) compared with the baseline (1.08±0.1 m/s, p=.015) and then significantly declined after a 2-week, treatment-free period (1.15±0.13 m/s; p=.048). Multivariate analysis revealed that the SOS score (p<.001) and lobular inflammation (p=.044) were independently correlated with the liver SWV. CONCLUSION: Liver SWV is elevated in SOS in proportion to the degree of sinusoidal injury and lobular inflammation in rat SOS models. ARFI elastography has potential as an examination for diagnosis, severity assessment and follow-up of SOS. KEY POINTS: • Liver SWV using ARFI elastography was significantly elevated in SOS rat. • Sinusoidal injury and lobular inflammation grades had correlation with liver SWV. • ARFI elastography has potential for diagnosis, severity assessment, and follow-up of SOS.

Prospective Comparison of the Diagnostic Performance of Magnetic Resonance Elastography with Acoustic Radiation Force Impulse Elastography for Pre-operative Staging of Hepatic Fibrosis in Patients with Hepatocellular Carcinoma.

The purpose of this study was to compare the diagnostic accuracy of magnetic resonance (MR) elastography with that of acoustic radiation force impulse (ARFI) elastography for pre-operative staging of hepatic fibrosis in patients with hepatocellular carcinoma. We prospectively enrolled 77 patients who were scheduled to undergo hepatectomy for hepatocellular carcinoma. Pre-operative MRE and ARFI elastography examinations were performed on the same day, and liver stiffness/velocity values were determined. Fibrosis stage and necro-inflammatory activity of resected specimens were determined histopathologically using the METAVIR scoring system. Correlations between MRE and ARFI elastography findings and histologic findings were determined by receiver operating characteristic (ROC) analysis. Correlation of MRE was excellent and correlation of ARFI elastography was good with fibrosis stage. MRE had better diagnostic performance than ARFI elastography in estimating substantial fibrosis (F2), severe fibrosis (F3) and cirrhosis (F4). The optimal cutoff value and the area under the ROC curve (AUROC) were determined using ROC curve analysis. The highest Youden index was used as a criterion for selecting the optimal cutoff value. ROC analysis revealed that MRE discriminated advanced stages of fibrosis (F ≥ 2) well in patients with hepatocellular carcinoma at a cutoff value of 3.0 kPa with an AUROC value of 0.93, and ARFI elastography did so at a cutoff value of 1.77 m/s with an AUROC value of 0.81 for predicting advanced stages of fibrosis (F ≥ 2). In conclusion, MRE is a more accurate imaging modality than ARFI elastography in estimating advanced stages of fibrosis and cirrhosis.

Acoustic Radiation Force Impulse Elastography in Determining the Effects of Type 1 Diabetes on Pancreas and Kidney Elasticity in Children.

OBJECTIVE: The aim of this study is to determine the effects of type 1 diabetes on pancreas and kidney elasticity in children, using acoustic radiation force impulse ultrasound elastography. SUBJECTS AND METHODS: Sixty autoantibody-positive patients with type 1 diabetes (45% girls; mean [± SD] age, 11.7 ± 4.4 years; range, 1.9-19.3 years) admitted to the pediatric endocrinology outpatient clinic and 32 healthy children (50% girls; mean age, 10.2 ± 3.8 years; range, 2.1-17.3 years) were included in the study. Acoustic radiation force impulse elastography measurements were performed of the kidneys and pancreas in both groups. Body mass index, duration of diabetes, HbA1c levels, and insulin dosage of patients with type 1 diabetes were recorded. RESULTS: The mean shear-wave velocities of the pancreas were 0.99 ± 0.25 m/s in patients with type 1 diabetes and 1.09 ± 0.22 m/s in healthy control subjects; the difference was not significant (p = 0.08). The median shear-wave velocities of the right and left kidneys in patients with type 1 diabetes were 2.43 ± 0.29 and 2.47 ± 0.25 m/s, respectively. There were no significant differences in the shear-wave velocities of the right and left kidneys between the patients with type 1 diabetes and the healthy control subjects (p = 0.91 and p = 0.73, respectively). Correlation analysis showed no correlation between the shear-wave velocities of the pancreas and kidney versus HbA1c level, duration of diabetes, insulin dosage, height, weight, and body mass index of the patients with type 1 diabetes. CONCLUSION: The current study showed no significant difference in the shear-wave velocity of kidneys in children with type 1 diabetes with normoalbuminuria compared with the healthy control subjects. We also observed that the shear-wave velocity of the pancreas in children with type 1 diabetes and healthy control subjects did not differ significantly.

Evaluation of Non-alcoholic Fatty Liver Disease Using Acoustic Radiation Force Impulse Imaging Elastography in Rat Models.

The aim of this study is to evaluate the utility of acoustic radiation force impulse (ARFI) elastography for assessing hepatic fibrosis stage and non-alcoholic fatty liver disease (NAFLD) severity, as well as the relationship among hepatic histologic changes using shear wave velocity (SWV). Animal models with various degrees of NAFLD were established in 110 rats. The right liver lobe was processed and embedded in a fabricated gelatin solution (porcine skin). Liver mechanics were measured using SWV induced by acoustic radiation force. Among the histologic findings, liver elasticity could be used to differentiate normal rats from rats with simple steatosis (SS) as well as distinguish SS from non-alcoholic steatohepatitis (NASH), with areas under the receiver operating characteristic curves (AUROC) of 0.963 (95% confidence interval = 0.871-0.973) and 0.882 (95% confidence interval = 0.807-0.956), respectively. For NAFLD rats, the diagnostic performance of ARFI elastography in predicting significant fibrosis (F ≥ 2) had an AUROC of 0.963. For evaluating steatosis severity, we found a progressive increase in ARFI velocity proportional to steatotic severity in NAFLD rat models, but we observed no significant differences for steatotic severity after excluding the rats with fibrosis. ARFI elastography may be used to differentiate among degrees of severity of NAFLD and hepatic fibrotic stages in NAFLD rat models.