A Preliminary Investigation of Normal Pancreas and Acute Pancreatitis Elasticity Using Virtual Touch Tissue Quantification (VTQ) Imaging

Diagnostic performance of acoustic radiation force impulse for acute pancreatitis: A meta-analysis

OBJECTIVE

The objective of this meta-analysis is to evaluate the diagnostic performance of acoustic radiation force impulse (ARFI) in acute pancreatitis (AP) patients.

METHODS

PubMed, Web of Science, Embase, Wanfang, Chinese Biological Medicine databases, and Chinese Biomedical Literature Service System were searched for relevant studies to explore the potential diagnostic performance of ARFI in AP from inception to November 2023. STATA 14.0 was used to analyze the standardized mean difference (SMD) with 95% confidence interval (CI), pooled sensitivity, specificity, area under the curve, meta-regression analysis, sensitivity analysis, and publication bias.

RESULTS

Nine studies, involving 533 AP patients and 585 healthy controls, were included. AP patients had significantly higher ARFI levels than healthy controls (SMD: 3.13, 95% CI: 1.88-4.39, P = .001). The area under the curve of ARFI for diagnosing AP was 0.99 (95% CI: 0.98-1.00), with 98% sensitivity and 94% specificity. Meta-regression identified the study region and study period as the sources of heterogeneity. Sensitivity analysis showed that the exclusion of any single study did not materially alter the overall combined effect. No evidence of publication bias was observed in the included studies.

CONCLUSION

This meta-analysis demonstrated that ARFI exerted satisfactory diagnostic performance in AP.

Estimating reference values of parenchymal stiffness of normal pancreatic parenchyma by means of point shear wave elastography

INTRODUCTION

There are numerous imaging modalities available to describe pancreatic parenchyma. None of the broadly accepted diagnostic methods uses elasticity as an indicator of tissue damage.

The Role of Transabdominal Ultrasound Elastography in Gastrointestinal Non-Liver Diseases: Current Application and Future Prospectives

Ultrasound imaging is the first-line investigation for patients with abdominal symptoms, as it effectively depicts the gastrointestinal tract and enables the diagnosis of multiple pathological conditions. Among different recent ultrasound technological advancements, elastography enables the evaluation of various tissue characteristics, such as neoplastic transformation or fibroinflammatory status. In recent years, ultrasound elastography has been utilized extensively for the study of liver diseases and in numerous other clinical settings, including gastrointestinal diseases. Current guidelines suggest the use of transabdominal ultrasound elastography to characterize bowel wall lesions, to assess gastrointestinal contractility, to diagnose and grade chronic pancreatitis; however, no specific indications are provided. In the present paper, we summarize the evidence concerning the application of different ultrasound elastography modalities in gastrointestinal non-liver diseases.

Sedative effect with the combination of butorphanol and midazolam on two-dimensional shear wave elastography of pancreas and kidney in healthy dogs

OBJECTIVE

To evaluate the sedative effect of a combination of butorphanol and midazolam on 2-D shear wave elastography (SWE) of the kidneys and pancreas in dogs.

ANIMALS

8 clinically healthy dogs.

PROCEDURES

We conducted a 2-D SWE examination of the bilateral kidneys and the pancreas before and after IV of 0.2 mg/kg butorphanol and 0.1 mg/kg midazolam in each dog. We performed 2-D SWE on the left kidney via a subcostal approach with the dog in right lateral recumbency, on the right kidney via the intercostal approach with the dog in left lateral recumbency, and on the right lobe of the pancreas via the subcostal approach. Subsequently, the pancreas and kidney shear wave velocities (SWV) pre- and postsedation were compared.

RESULTS

On qualitative evaluation using color mapping, the pancreas and kidneys showed a homogeneous blue-to-green color in pre- and post-sedation 2-D SWE. There was no significant difference in SWV pre- and post-sedation in the pancreas and kidneys.

CLINICAL RELEVANCE

Intravenous administration of a combination of 0.2 mg/kg butorphanol and 0.1 mg/kg midazolam did not change the 2-D SWE of the pancreas and kidneys significantly. The combination of butorphanol and midazolam can be used in healthy dogs for 2-D SWE evaluation of the pancreas and kidneys, especially when the patient is uncooperative during the examination.

Ultrasound Shear Wave Elastography of Normal Pancreas in Adult Subjects

Background and Purpose Transabdominal ultrasound (US)-based shear wave elastography (SWE) provides an attractive method of estimating pancreatic stiffness. There is limited data on the SWE values of the healthy pancreas in Indian subjects. The current study aimed to evaluate SWE of the normal pancreas.

Methods We performed a study from January 2019 to March 2019. We included adult patients who presented for the US of the upper abdomen for vague abdominal symptoms, unrelated to the pancreas. The SWE values were obtained from the pancreatic head and body. The association of pancreatic SWE with age, gender, fatty liver, chronic liver disease, and cholelithiasis was recorded.

Results During the study period, 205 subjects underwent SWE of the pancreas. The mean age of subjects was 41.3 (standard deviation [SD] 15.3) years. There were 93 males and 112 females. The mean SWE value in the head of the pancreas was 8.98 (SD 2.46 kPa), and that in the body region was 8.67 (SD 2.67 kPa). There was a positive correlation of SWE with age. The SWE of the pancreatic body was significantly higher in patients who had a fatty liver on US (p < 0.05). There was no significant association of SWE of the pancreas with gender, presence of chronic liver disease, or gallstones.

Conclusion The normal values of pancreatic SWE are correlated with age and fatty change in the liver.

Evaluation of the Elasticity of the Pancreas Using Acoustic Radiation Force Impulse Elastography in Patients with Acute Pancreatitis: A Systematic Review and Meta-Analysis

Acoustic radiation force impulse (ARFI) elastography has been used to diagnose acute pancreatitis (AP). The present study aimed to assess the effectiveness of ARFI elastography in the diagnosis of AP. Studies examining the efficacy of ARFI elastography in AP were selected by searching MEDLINE, EMBASE, CENTRAL, ICTRP, and ClinicalTrial.gov. until September 2021. Meta-analyses were performed using random effects models. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to assess the certainty of the evidence. Eight case-control studies (994 patients) were included in the meta-analysis. The ARFI-Virtual Touch Quantification value (or ARFI shear wave propagation velocity) of the AP patient group was 0.83 m/s higher (95% confidence interval [CI]: 0.36-1.3) than that in the control group (95% CI: 1.0-1.28). The sensitivity and specificity of ARFI elastography for diagnosing AP were 98.3% (95% CI: 92.6-96.6%) and 95.5% (95% CI: 87.5-98.5%), respectively. The results showed that physicians could use ARFI elastography to accurately diagnose patients with AP. Additional well-designed studies are necessary to validate the efficacy of ARFI elastography in patients with AP.

Pancreatic Steatosis Is Associated with Both Metabolic Syndrome and Pancreatic Stiffness Detected by Ultrasound Elastography

INTRODUCTION

There is increasing evidence that pancreatic steatosis (PS) is associated with metabolic syndrome (MS). However, it is not known whether it is associated with PS grade and pancreatic stiffness, or not. We aimed to evaluate the relationship between PS and its grade detected by transabdominal ultrasound, and pancreatic stiffness determined by two-dimensional shearwave elastography (2D-SWE), whether it has clinical significance and its relationship with MS.

METHODS

Patients with and without PS were evaluated prospectively.

RESULTS

Patients with PS had higher odds ratio for MS (OR 5.49). Also, ultrasonographic grade of PS was associated with MS parameters and hepatosteatosis. Pancreatic SWE value was significantly higher in PS group and positively correlated with PS grade, liver fat, MS, number of MS criteria.

DISCUSSION/CONCLUSION

PS and its grade were associated with MS. In this first comprehensive PS-SWE study, we found that pancreas stiffness increased in the presence of PS, in correlation with PS grade and MS.

Evaluation of children and adolescent with cystic fibrosis by pancreatic elastography

BACKGROUND

Cystic fibrosis (CF) is an autosomal recessively inherited disease. Clinical findings vary by age of the patient, the organ systems involved, and the severity of the CFTR gene mutation. Pancreatic and liver involvement is prominent and exocrine pancreatic insufficiency is observed in the majority of patients. Point shear wave elastography (pSWE) is a non-invasive method that can quantitatively determine tissue elasticity and stiffness. In this study, the morphological evaluation of the pancreas was performed using the pSWE technique in pediatric patients diagnosed with CF. The effectiveness of this method for the early detection of pancreatic insufficiency was investigated.

METHODS

Fifty-five patients with CF (24 girls, 31 boys) and 60 healthy children (29 girls, 31 boys) without any chronic diseases and who were suitable for the pSWE examination were included in the study.

RESULTS

The mean value of pSWE was 1.12 ± 0.16 in the healthy group and 0.97 ± 0.16 in the patients with cystic fibrosis. There was a statistically significant difference between the two groups (P < 0.001). Significant negative correlations were found between pSWE and age (r = -0.319; P = 0.018), height (r = -0.293; P = 0.03), serum glucose (r = -0.346; P = 0.01), HbA1C (r = -0.592; P = 0.02), and duration of the disease (r = -0.806; P < 0.001).

CONCLUSIONS

Investigating pancreatic elasticity and detecting pancreatic insufficiency using pSWE (a simple, inexpensive, and non-invasive method) in the early period before overt laboratory and clinical symptoms of EPI appear can contribute positively to long-term results in young patients with CF.

Comparison of the diagnostic value of virtual touch tissue quantification and virtual touch tissue imaging quantification in infants with biliary atresia

OBJECTIVE

This study aimed to compare the diagnostic performance of vital touch tissue quantification (VTQ) and virtual touch tissue imaging quantification (VTIQ) in diagnosing infants with biliary atresia (BA) from jaundiced infants.

METHODS

In this study, 26 jaundiced infants with BA, 33 jaundiced infants without BA, and 40 normal infants were enrolled. The hepatic shear wave velocity (SWV) of each infant was determined by VTQ and VTIQ examinations, respectively. Then, the receiver operating characteristic (ROC) curves were drawn and the area under the curve (AUC) and optimal cut-off values were calculated to evaluate the sensitivities and specificities of VTIQ and VTQ for BA.

RESULTS

The mean values of SWV of the control group measured by VTQ and VTIQ were (1.09 ± 0.18) m/s and (1.36 ± 0.21) m/s, respectively. The mean values of SWV of the non-BA group measured by VTQ and VTIQ were (1.30 ± 0.28) m/s and (1.52 ± 0.29) m/s, respectively. The mean values of SWV of the BA group measured by VTQ and VTIQ were (2.36 ± 0.36) m/s and (2.43 ± 0.29) m/s, respectively. The diagnostic threshold of VTQ and VTIQ to diagnose BA was 1.77 and 1.92 m/s. The sensitivities of VTQ and VTIQ to diagnose BA were 90.9% and 95.5%. The specificities of VTQ and VTIQ to diagnose BA were 68.4% and 78.9%.

CONCLUSION

Vital touch tissue quantification and VTIQ could help distinguish infants with BA from jaundiced infants by measuring the liver SWV values. VTIQ has higher sensitivity and specificity than VTQ.

Pancreas ultrasound two-dimensional shear wave elastography in healthy children

BACKGROUND

Pancreas shear wave speed might be a biomarker of pancreatic disease in children.

OBJECTIVE

This study aimed to measure pancreas shear wave speed by two-dimensional (2-D) ultrasound shear wave elastography (SWE) in a balanced cohort of presumed healthy children.

MATERIALS AND METHODS

This was a prospective study of 120 children (<18 years of age) without a known history of pancreatic disease, who underwent ultrasound 2-D SWE of the pancreas. Five shear wave speed measurements in the pancreas body and/or tail were obtained for each participant using a Canon Aplio i800 system, i8CX1 transducer. The Mann-Whitney U test or Kruskal-Wallis test were used to compare continuous distributions. Spearman's correlation was used to assess univariate relationships between continuous variables. Multivariable regression with stepwise selection was used to evaluate independent predictors of pancreas shear wave speed.

RESULTS

The median age for the study population was 5.0 years (range: 7 days to 17.8 years) and 61 (50.8%) of the participants were female. The median depth of shear wave speed measurement was 4.7 cm (interquartile range [IQR]: 4.2-5.3). The median pancreas shear wave speed was 1.31 m/s (IQR: 1.21-1.40). On multivariable analysis, female biological sex (P=0.051), the number of hours nil per os (P=0.097), the median depth of measurement (P=0.001) and the median liver shear wave speed (P=0.020) were positively associated with pancreas shear wave speed.

CONCLUSION

We report pancreas shear wave speed in a large, balanced cohort of children without a known history of pancreatic disease, providing reference values for normal.

Quantitative shear wave elastography for noninvasive assessment of solid pancreatic masses

PURPOSE

To evaluate the diagnostic value of quantitative shear wave elastography (SWE) for the differential diagnosis of solid pancreatic tumors.

MATERIALS AND METHODS

A total of 66 solid pancreatic masses were enrolled in this study and all the lesions underwent quantitative SWE. The stiffness of the masses was expressed in shear wave velocity (SWV, m/s). The receiver operating characteristic (ROC) curve was plotted to assess the diagnostic performance of quantitative SWE. The optimal cutoff value for SWV in the differentiation of benign from malignant masses was determined.

RESULTS

The final diagnoses were 26 benign and 40 malignant masses. The SWVs were statistically higher for pancreatic malignant masses compared with those for benign masses (3.30±1.22 m/s versus 1.31±0.64 m/s; P < 0.001). The area under the curve (AUC, 0.93) was obtained. When the best cut-off point was 1.77 m/s, the accuracy, sensitivity, and specificity were 92.4%, 90.0%, and 96.2%, respectively.

CONCLUSIONS

Quantitative SWE is a novel technique that can be considered as a quantitative and objective diagnostic tool for prediction of pancreas malignancy.

Diagnostic performances of the KWAK-TIRADS classification, elasticity score, and Bethesda System for Reporting Thyroid Cytopathology of TI-RADS category 4 thyroid nodules

OBJECTIVE

To explore the value of the KWAK Thyroid Imaging Reporting and Data System (KWAK-TIRADS), elasticity score (ES), and Bethesda System for Reporting Thyroid Cytopathology (BSRTC) in the diagnosis of suspicious thyroid nodules.

MATERIALS AND METHODS

The study included 392 cases of TI-RADS category 4 thyroid nodules that underwent thyroidectomy between January 2017 and October 2019. All patients underwent ultrasonography, ultrasound elastography, and fine-needle aspiration cytology (FNAC) before surgery. The nodules were classified into different categories based on the KWAK-TIRADS, ES, and BSRTC. Patients were divided into two groups based on postoperative pathological characteristics. The sensitivity (Se), specificity (Sp), and area under the receiver operating characteristic (ROC) curve were calculated. Student's t-test and Pearson chi-square test were used to compare diagnostic performance.

RESULTS

There were 159 patients in the benign group and 233 in the malignant group. The percentage of malignant nodules in KWAK-TIRADS categories 4a, 4b, and 4c were 44.3%, 64.8%, and 92.9%, respectively. The percentages of malignant nodules in ES 2, 3, 4, and 5 were 0%, 37.1%, 93.8%, and 100%, respectively. The percentage of malignant nodules in BSRTC levels I, II, III, IV, V and VI were 57.1%, 2.8%, 9.9%, 76.6%, 99.1%, and 100%, respectively. Among those methods, the BSRTC had better diagnostic efficiency than the KWAK-TIRADS and ES (Sp 81.1%, Se 93.6%, and AUC 0.918, P<0.01). Among the combined methods, KWAK-TIRADS+ES+BSRTC was more effective than KWAK-TIRADS+ES, KWAK-TIRADS+BSRTC, and ES+BSRTC (Sp 93.7%, Se 91.4%, and AUC 0.967, P<0.01).

CONCLUSION

The combination of KWAK-TIRADS, ES, and BSRTC can improve the accuracy of identifying category 4 thyroid nodules.

Pancreatic ultrasound elastography is not useful to predict the risk of pancreatic fistulas after pancreatic resection

The clinical usefulness of pancreatic elastography (PE) in the assessment of the pancreatic texture before pancreatic resection still remains uncertain. The aims are: to evaluate the value of pancreatic stiffness in both healthy volunteers and patients affected by pancreatic tumor; to evaluate the ability of PE in predicting clinically relevant postoperative pancreatic fistula (CR-POPF). Pancreatic stiffness of healthy subjects was compared with those of pancreatic tumors measuring shear wave velocity (SWV). In the last group, the ability of preoperative SWV in predicting CR-POPF was evaluated using linear regression. Ninety subjects were consecutively enrolled. No difference was found in SWV in the two groups (1.33 ± 0.31 vs 1.26 ± 0.30, p = 0.337). Multivariate analyses showed that male gender was associated with a softer pancreas (OR 0.74, CI 0.55-0.98, p = 0.035). In the 45 patients suitable for a secondary endpoint, the presence of soft pancreas assessed by surgeon's palpation (OR 61.21; CI 2.14- > 1000; p = 0.016) and preoperative risk score (OR 1.72; CI 1.01-2.96; p = 0.049) was predictors of CR-POPF. SWV showed a trend in predicting CR-POPF. The pancreatic stiffness far to the pancreatic neoplasm is the same as healthy controls. SWV showed a trend in predicting CR-POPF but the clinical utility is limited.

Quantification of pancreatic elasticity in type 2 diabetes: A new potential imaging marker for evaluation of microangiopathy

PURPOSE

The aim of this study was to noninvasively explore pancreatic morphological and mechanical changes in diabetic patients with or without microangiopathy and to investigate the clinical correlations of pancreatic stiffness or size with diabetic microangiopathy.

METHODS

A total of 213 type 2 diabetic patients with / without microangiopathy (91/122) were prospectively enrolled. Microangiopathy included diabetic retinopathy, diabetic nephropathy and diabetic peripheral neuropathy. Each subject underwent pancreatic ultrasonography and elastography. The shear wave velocity (SWV) and thickness of the head, body and tail were measured and compared. Receiver operating characteristic (ROC) curves was performed in the diagnosis of microangiopathy. Risk factors of the occurrence of more microvascular complications were explored.

RESULTS

The SWV in pancreas increased significantly in patients with microangiopathy (P < 0.01) while the thickness was similar in all patients. The area under ROC curve for the SWV in pancreatic body was greatest (0.747) and the sensitivity, specificity were 73.0, 70.9 %. There was a significant shift towards the occurrence of more microvascular complications for patients with increasing of the SWV in pancreatic body (OR 39.25), long duration of diabetes (OR 1.077), aging (OR 1.039) and elevation of microalbuminuria (OR 1.004).

CONCLUSIONS

The SWV in pancreatic body was significantly high in diabetic patients with microangiopathy and was prominently correlated with the number of microvascular complications. The SWV in pancreatic body may be considered as a potential marker for diabetic microangiopathy and its occurrence.

Attenuation Measuring Ultrasound Shearwave Elastography as a Method for Evaluating Pancreatic Viscoelasticity

Pancreatic cancer is the fourth most common cause of cancer-related fatalities as there are a limited number of tools to diagnose this disease in its early stages. Pancreatitis is characterized as an inflammation of the pancreatic tissue due to an excess amount of pancreatic enzymes remaining in the organ. Both of these diseases result in a stiffening of the tissue which makes them suitable for the use of elastography techniques as a diagnostic method. However, these methods typically assume that the tissue is purely elastic when biological tissue is inherently viscoelastic. The attenuation measuring ultrasound shear elastography (AMUSE) method, which measures both attenuation and shear wave velocity was used to characterize the viscoelasticity of pancreatic tissue. This method was tested in ex vivo normal porcine samples that were also stiffened in formalin and in vivo by conducting studies in healthy human subjects. Ex vivo testing showed ranges of phase velocity, group velocity, and phase attenuation values of 1.05 - 1.33 m/s, 0.83 - 1.12 m/s, and 183 - 210 Np/m. After immersing the ex vivo tissue in formalin there was a distinguishable difference between normal and stiffened tissue. This study produced percent difference ranges of phase velocity, group velocity, and phase attenuation from 0 to 100 minutes in formalin of 30.0% - 56.5%, 38.2% - 58.6%, and 55.8% - 64.8%, respectively. The ranges of phase velocity, group velocity, and phase attenuation results in human subjects were 1.53 - 1.60 m/s, 1.76 - 1.91 m/s, and 196 - 204 Np/m, respectively. These results were within a similar range reported by other elastography techniques. Further work with the AMUSE method in subjects with pancreatitis and cancer is needed to determine its effectiveness in showing a difference between healthy and diseased tissue in humans.

Elastography of the Pancreas, Current View

Ultrasound elastography (USE) of the pancreas allows pancreatic tissue stiffness assessment by virtual palpation. Two main types of USE are used. For the pancreas strain elastography applying by endoscopic ultrasound has been established for the characterisation of small solid pancreatic lesions (SPL). In larger SPL >30 mm the results are less convincing mainly due to the heterogenicity of the lesions but also by concomitant changes of the surrounding pancreatic parenchyma. The current role of shear wave elastography has to be determined. This article reviews the current use of elastography of the pancreas.

Ultrasound point shear wave elastography of the pancreas: comparison of patients with type 1 diabetes and healthy volunteers - results from a pilot study

Background

The aims of this study were to establish shear wave elastography of the pancreas by comparing measurements in patients with type 1 diabetes (T1D) and healthy volunteers and to consider whether this method could contribute to the screening or prevention of T1D.

Methods

This pilot study included 15 patients with T1D (10 men, 5 women) and 15 healthy volunteers (10 men, 5 women) as controls. Measurements were performed with a Siemens Acuson S3000 (Siemens Healthcare, Erlangen, Germany) using a 6C1 convex transducer and the Virtual Touch™ tissue quantification (VTQ) method.

Results

The mean shear wave velocity of the head of the pancreas was 1.0 ± 0.2 m/s (median: 1.1 m/s) for the study group and likewise 1.0 ± 0.2 m/s (median: 0.9 m/s) for the control group. Velocities of 1.2 ± 0.2 m/s (median: 1.2 m/s) were measured in the body of the pancreas in both groups. There was a significant difference between the values obtained in the tail of the pancreas: patients 1.1 ± 0.1 m/s (median: 1.0 m/s) versus controls 0.9 ± 0.1 m/s (median: 0.8 m/s) (p = 0.0474). The mean value in the whole pancreas of the study group was not significantly above that of the control group: 1.1 ± 0.1 m/s (median: 1.0 m/s) versus 1.0 ± 0.1 m/s (median: 1.0 m/s) (p = 0.2453).

Conclusions

Sonoelastography of the pancreas revealed no overall difference between patients with T1D and healthy volunteers. Patients with T1D showed higher values only in the tail segment. Future studies need to determine whether specific regional differences can be found in a larger study population.

The importance of acoustic radiation force impulse (ARFI) elastography in the diagnosis and clinical course of acute pancreatitis

BACKGROUND/AIMS

Acute pancreatitis (AP) is characterized by acute inflammation of the pancreas and it has a highly variable clinical course. The aim of our study was to evaluate the value of acoustic radiation force impulse (ARFI) elastography in the diagnosis and clinical course of AP.

MATERIALS AND METHODS

Consecutive patients with a diagnosis of AP (patients group) and healthy subject (control group) were prospectively enrolled to the study. Demographic features and clinical, laboratory, and radiological data were recorded. Virtual Touch Tissue Quantification (VTQ) was used to implement ARFI elastography. The tissue elasticity is proportional to the square of the wave velocity (SWV).

RESULTS

A total of 108 patients (age, 57±1.8 y) and 79 healthy subjects (age, 53.6±1.81 y) were included in the study. There were 100 (92.5%) edematous and 8 (7.4%) necrotizing AP. The mean SWV was significantly higher in the patient group than in the control group (2.43±0.08 vs. 1.27±0.025 m/s, p < 0.001). There was not significant difference between patient and control group regarding age and gender. SWV cutoff value of 1.63 m/s was associated with 100% sensitivity and 98% specificity for the diagnosis of AP. There was not significant difference between patients with and without complications and patients with edematous and necrotizing AP regarding mean SWV value. There was also not significant correlation between mean SWV value and age, mean length of hospital stay, and mean amylase level.

CONCLUSION

ARFI elastography may be a feasible method for the diagnosis of AP, but it has no value for the prediction of clinical course of AP.

Diagnostic Performance of Superb Microvascular Imaging (SMI) Combined with Shear-Wave Elastography in Evaluating Breast Lesions

Background

This study explored the diagnostic value of a combined modality of Superb Microvascular Imaging (SMI) and shear-wave elastography in differentiating malignant and benign breast lesions.

Material/Methods

A total of 121 patients with 123 breast lesions enrolled underwent conventional ultrasound exam (US), Color Doppler Flow Imaging (CDFI), SMI examination, and Virtual Touch Tissue Quantification (VTQ) measurement between May 2016 and October 2017. Vessels were detected by both CDFI and SMI in a quantitative manner. The stiffness of all the breast tissues was evaluated by VTQ method. We further assessed the diagnostic performances of CDFI, SMI, VTQ, CDFI+VTQ, and SMI+VTQ.

Results

Both CDFI and SMI exhibited significant differences between malignant and benign masses (p<0.001) in terms of Adler classification. The mean shear-wave velocity (SWV) of malignant neoplasms was 5.28 m/s, with interquartile range (IQR) 4.01–6.39 m/s (p<0.001). The mean SWV of benign lesions was 2.64 m/s, with IQR 2.30–5.01 m/s (p<0.001). No significant difference was found for the area under the receiver operating characteristic curve (AUC) for CDFI, SMI, and VTQ (χ²=2.29, P=0.3715). The sensitivity was the highest on SMI+VTQ (85.42%) and the lowest on CDFI (58.33%). CDFI+VTQ (85.33%) had a slightly higher specificity than SMI+VTQ (84.00%). The accuracy rate of these 2 modalities remained the same (84.55%).

Conclusions

Superb Microvascular Imaging yields more detailed vascular information in the bloodstream in benign and malignant breast masses compared with conventional ultrasonography. VTQ provides standardized quantified results in assessing tissue stiffness. The combined modality of SMI+VTQ added to conventional ultrasonography presented a better diagnostic performance in differentiating malignant breast neoplasms.

Pancreatic Elastography From Acoustic Radiation Force Impulse Imaging for Evaluation of Diabetic Microangiopathy

OBJECTIVE

The purposes of this study were to compare pancreatic shear-wave velocity (SWV) in subjects with and those without diabetic microvascular complications and to investigate the feasibility of pancreatic SWV in evaluating diabetic microangiopathy.

SUBJECTS AND METHODS

SWV measurements were prospectively performed in 115 patients with diabetes mellitus and 115 healthy persons by use of acoustic radiation force impulse imaging. Patients with diabetes were divided into subgroups with and without microangiopathy. Pancreatic SWV was compared in three groups. Factors associated with increased SWV were studied.

RESULTS

Pancreatic SWV increased significantly in the subgroups with diabetes mellitus compared with the control group (p < 0.01). Especially, the SWV in the pancreatic body was significantly higher when microangiopathy was present (p < 0.01). In patients with diabetes, microangiopathy (standardized β = 0.208, p = 0.022), age (standardized β = 0.265, p = 0.004), and total cholesterol level (standardized β = 0.223, p = 0.011) were positively and markedly correlated with high SWV in the pancreatic body.

CONCLUSION

The increased SWV in the pancreatic body was significantly related to the presence of microangiopathy. It is feasible to use SWV in the pancreatic body to evaluate diabetic microangiopathy.

Influence of age, sex, body mass index, alcohol, and smoking on shear wave velocity (p-SWE) of the pancreas

Purpose

A variety of elastographic techniques have been developed to facilitate the non-invasive assessment of tissue properties. The goal of the study was to examine the influence of gender, age, BMI, alcohol consumption, and smoking in healthy volunteers.

Methods

Of the 263 participants who met all the study inclusion criteria, 234 had successful measurements. The examination was performed with the Siemens Acuson S3000 (Siemens Healthcare, Erlangen, Germany), using the 6C1 curved array transducer with the virtual touch tissue quantification (VTQ) method.

Results

The values determined with the curved array in the head of the pancreas were 1.44 ± 0.39 m/s for women and 1.19 ± 0.29 m/s for men; in the body, the results were 1.49 ± 0.37 m/s for women and 1.26 ± 0.30  m/s for men; in the tail, the corresponding values were 1.29 ± 0.36 m/s for women and 1.05 ± 0.30 m/s for men. Comparison of gender showed that men have significantly lower mean values than women. There were significantly higher values in all parts of the organ with the increasing age of the participants (p < 0.0001). For BMI, there was a significant correlation with the values only when considering the BMI in continuous form. Alcohol consumption and smoking did not have any significant effects.

Conclusions

ARFI-VTQ is qualified for use on pancreatic tissue. Further studies are required to examine the influence of other factors in larger populations.

Measurement of elasticity of normal placenta using the Virtual Touch quantification technique

Purpose:

The aim of this study was to measure the elasticity of normal placentas using the Virtual Touch quantification (VTQ) technique.

Methods:

This study was approved by the Institutional Ethics Committee. Fifty randomly selected, healthy pregnant women in their second trimester and 50 randomly selected, healthy pregnant women in their third trimester with a single fetus were included, and their placentas underwent VTQ through shear wave velocity (SWV) measurements. The measurements were performed at different locations to sample different areas of the placenta. Measurements were performed 3-4 times in each location, the mean shear wave velocities were calculated without the highest and lowest values of measurements in each region, and the results were compared.

Results:

The SWV of the placenta was 0.983±0.260 m/sec, and the minimal and maximal speed was 0.63 m/sec and 1.84 m/sec, respectively. There was no significant difference between the second and third trimester of VTQ of the placenta in terms of SWV (0.978±0.255 m/sec vs. 0.987±0.266 m/sec, P=0.711). The maternal age between second and third trimester was 27.9±4.3 years and 29.2±4.4 years, respectively; there was no significant difference between them (P=0.159).

Conclusion:

The results of this study show that the SWV of normal placenta tissue is 0.983±0.260 m/sec, it has little variation between the second and third trimesters, and the VTQ technique may potentially play an additional role in placenta evaluation.

The utility of ultrasound elastography in differentiation of endometriomas and hemorrhagic ovarian cysts

PURPOSE

To investigate the feasibility of acoustic radiation force impulse imaging in differentiation of endometriomas and hemorrhagic ovarian cysts.

MATERIALS AND METHODS

We evaluated 84 ovarian cysts with high internal echogenicity diagnosed in 70 consecutive women. We excluded simple cysts and hemorrhagic cysts containing septations or mural nodules with detectable flow on Doppler ultrasonography. We obtained the elastographic shear wave velocity (SWV) value of the cysts that could be endometriomas or hemorrhagic ovarian cysts.

RESULTS

Among the 78 ovarian cysts in 70 women without any septation or mural nodule, there were 42 endometriomas and 36 hemorrhagic ovarian cysts. Analysis of median SWV values of the ovarian cysts showed that the endometriomas had considerably higher levels of stiffness compared to the hemorrhagic ovarian cysts [median SWV 4.20 ± 0.42 vs 2.54 ± 1.04 m/s, p < 0.001]. A SWV cutoff value greater than 3.81 m/s yielded sensitivity and specificity values of 82.1 and 79.2 % respectively, for differentiation of endometriomas from hemorrhagic ovarian cysts.

CONCLUSION

Sonoelastography is a novel imaging technique that enables us to evaluate the stiffness of adnexal lesions. The accurate discrimination of endometriomas and hemorrhagic ovarian cysts is important for avoiding unnecessary surgical procedures. ARFI imaging has a high sensitivity and specificity for distinguishing endometrioma from hemorrhagic ovarian cysts.

Clinical Values of Studying Kidney Elasticity with Virtual Touch Quantification in Gestational Hypertension Patients

BACKGROUND The aim of this study was to investigate the differences in shear wave velocity (SWV) in renal cortex, renal medulla, and renal sinuses between gestational hypertension and normal pregnant women. MATERIAL AND METHODS Ninety patients with gestational hypertension and 30 women with normal pregnancy were enrolled in this study. Kidney biopsy was performed within 6 weeks to 3 months postpartum to determine the pathological nature of renal injury. According to the classification criteria for gestational hypertension, the patients were divided into 3 groups. Gestational hypertension only patients were classified as Group A; patients with mild preeclampsia as group B; patients with severe preeclampsia as group C; normal pregnant women as a control group. Virtual Touch Quantification technique was used to measure renal shear wave velocity; blood pressure, urine analysis, and renal function were also tested. RESULTS There was no difference in renal function between patients in group A and the control group (p>0.05), but there was a significant difference in renal function among patients in group A, B, and C, and there was a significant difference in renal function between patients in group B and C versus control (p<0.05 for all comparisons). There was also a significant difference in SWV values of the renal cortex, renal medulla, and renal sinus between patients in group A, B, and C versus control group (p<0.05). CONCLUSIONS The SWV values of the renal cortex, renal medulla, and renal sinus in patients with gestational hypertension were smaller than those of normal pregnant women, and the more severe the kidney injury, the smaller the SWV value.