Tissue Elastography Research Articles

Can ultrasound elastography be useful in the diagnosis of poor ovarian response?

This study aims to compare the elastographic properties of the ovaries of patients with poor ovarian response (POR) with healthy controls by using real-time ultrasound tissue elastography and to investigate the predictive value of ovarian strain ratio (OSR) in the diagnosis of POR. A cross-sectional study was conducted among infertility patients. OSR measurements of 46 women diagnosed with POR and 41 healthy controls with male infertility were performed by real-time ultrasound tissue elastography. Ovarian volume, OSR, antral follicle count (AFC), age, body mass index (BMI), anti-mullerian hormone (AMH), follicle stimulating hormone (FSH), and estradiol (E2) values, were compared between the groups. A receiver operating characteristic curve was used to compare the sensitivity and specificity of OSR, AFC, AMH, FSH, and E2 for POR diagnosis. Patients with POR were significantly older, had a lower duration of infertility, lower AMH, higher FSH, higher E2, lower AFC and ovarian volume (p < 0.01, p = 0.02, p < 0.01, p < 0.01, p < 0.01, p < 0.01, p < 0.01, respectively). The mean OSR of both ovaries was similar between the groups. For the diagnosis of POR, the sensitivity and specificity for AMH were 97.5% and 100%, for AFC were 86.7% and 97.6%; for FSH were 66.7% and 80.5%, for E2 were 53.3% and 90.2%, respectively. The significant independent predictors of the POR were AMH, AFC, and FSH, with no additional significant contribution from OSR. However, considering the relationship between POR and ovarian fibrosis, it is recommended to investigate this issue in more comprehensive studies.

Establishing Reference Values for Vaginal Vestibule Elastography in Healthy Postmenopausal Women.

Objective This study aims to establish normative elastography values for the vaginal vestibule in healthy postmenopausal women and assess the variability of these values with age and measurement time during the day. Methods The study included 111 women aged 40-90, excluding those with medical histories or treatments affecting vaginal health. Elastography measurements were taken twice daily, between 9-10 AM and 3-4 PM, using real-time tissue elastography technology. Statistical analysis evaluated the effects of age, body mass index (BMI), and diurnal variation on vaginal vestibule elasticity. Results A significant positive correlation between age and elastography values was found (p=8.36×10⁻⁷), with elastography values increasing by approximately 0.0040 units per year. The mean elastography value was 28.32% (SD=5.87%) in the morning and 28.10% (SD=5.90%) in the afternoon, with a statistically significant difference (p=0.016). BMI showed a weak negative correlation with elastography values (r=-0.2021, p=0.0334). Conclusion Establishing reference values for vaginal vestibule elastography provides a foundation for improved diagnostic accuracy and early detection of gynecological conditions. The findings support the use of elastography as a non-invasive, reliable diagnostic tool in clinical practice. Future research should validate these results across different age groups and in women with specific gynecological conditions to further solidify the clinical applicability of vaginal vestibule elastography.

Reliability of ultrasound real‐time tissue elastography in evaluating swallowing‐related muscle elasticity and effects of swallowing exercises

AbstractIntroductionEvaluating swallowing function, essential for eating, is necessary to detect functional decline, enabling the provision of effective interventions. There is a growing demand for a simple method for evaluating swallowing dynamics. Conventional methods of evaluating swallowing function, such as the fibreoptic endoscopic evaluation of swallowing or videofluoroscopic swallowing study, are highly invasive and require specific equipment only available at certain hospitals, making it difficult for older adults to receive convenient evaluations. Therefore, we used ultrasound real‐time tissue elastography (RTE), a low‐invasive method, to evaluate tissue elasticity as the strain ratio (SR). This study primarily aimed to verify whether RTE can evaluate the elasticity of swallowing‐related muscles (SRMs) and determine intra‐ and inter‐rater reliabilities. The secondary aim was to investigate the effect of swallowing exercises, such as head‐lifting exercises, on SRM elasticity.MethodsIntraclass correlation coefficients for SR were calculated using ultrasound B‐mode images to determine the reliability of SRM elasticity. SRs before and after the Shaker swallowing exercise were compared using the Wilcoxon signed‐rank test.ResultsHigh ICCs for intra‐ and inter‐rater reliabilities were obtained for all targeted SRMs. SR after the Shaker exercise indicated a significant decrease in the geniohyoid muscle and both sides of the digastric muscles, whereas both sides of the masseter exhibited no changes.ConclusionRTE can be used as a novel simple and non‐invasive method for assessing and capturing differences in SRs of SRMs after light exercise. Further research may develop a relationship with swallowing function in patients with dysphagia or older individuals.

Evaluation of anorectal function using real-time tissue elastography before and after preoperative chemoradiotherapy

PurposeThis study aimed to clarify the relationship between changes in elasticity and anorectal function before and after chemoradiotherapy.MethodsThis is a single-center prospective cohort study (Department of Surgical Oncology, The University of Tokyo). We established a technique to quantify internal anal sphincter hardness as elasticity using transanal ultrasonography with real-time tissue elastography. Twenty-seven patients with post-chemoradiotherapy rectal cancer during 2019–2022 were included. Real-time tissue elastography with transanal ultrasonography was performed before and after chemoradiotherapy to measure internal anal sphincter hardness as “elasticity” (hardest (0) to softest (255); decreased elasticity indicated sclerotic changes). The relationship between the increase or decrease in elasticity pre- and post-chemoradiotherapy and the maximum resting pressure, maximum squeeze pressure, and Wexner score were the outcome measures.ResultsA decrease in elasticity was observed in 16/27 (59.3%) patients after chemoradiotherapy. Patients with and without elasticity decrease after chemoradiotherapy comprised the internal anal sphincter sclerosis and non-sclerosis groups, respectively. The maximum resting pressure post-chemoradiotherapy was significantly high in the internal anal sphincter sclerosis group (63.0 mmHg vs. 47.0 mmHg), and a majority had a worsening Wexner score (60.0% vs. 18.2%) compared with that of the non-sclerosis group. Decreasing elasticity (internal anal sphincter sclerosis) correlated with a higher maximum resting pressure (r = 0.36); no correlation was observed between the degree of elasticity change and maximum squeeze pressure.ConclusionInternal anal sphincter sclerosis due to chemoradiotherapy may correlate to anorectal dysfunction.

Ultrasonic surface acoustic wave elastography: A review of basic theories, technical developments, and medical applications.

Physiological and pathological changes in tissues often cause changes in tissue mechanical properties, making tissue elastography an effective modality in medical imaging. Among the existing elastography methods, ultrasound elastography is of great interest due to the inherent advantages of ultrasound imaging technology, such as low cost, portability, safety, and wide availability. However, most current ultrasound elastography methods are based on the bulk shear wave; they can image deep tissues but cannot image superficial tissues. To address this challenge, ultrasonic elastography methods based on surface acoustic waves have been proposed. In this paper, we present a comprehensive review of ultrasound-based surface acoustic wave elastography techniques, including their theoretical foundations, technical implementations, and existing medical applications. The goal is to provide a concise summary of the state-of-the-art of this field, hoping to offer a reliable reference for the further development of these techniques and foster the expansion of their medical applications.

Value of real-time tissue elastography diffusion quantitative analysis combined with tumor markers for differential diagnosis of benign and malignant breast nodules

Background/Aim. Serum tumor markers (TMs) are commonly combined with imaging examinations to differentiate benign and malignant breast nodules (BNs), but there are still limitations. The aim of the study was to determine the value of real-time tissue elastography (RTE) diffusion quantitative analysis combined with serum TMs for the differential diagnosis of benign and malignant BNs. Methods. A total of 149 patients with BNs were included in this study. They were assigned to the benign BN group (n = 87) and malignant BN group (n = 62). All patients were examined using RTE diffusion quantitative analysis. Venous blood was collected to detect the levels of TMs carcinoembryonic antigen-CAE, cancer antigen (CA) 153, and CA 199. The value of RTE diffusion quantitative analysis parameters, TMs, and their combination for the differentiation of benign and malignant BNs was analyzed using the receiver operating characteristic-ROC curve. Results. Among all the above indicators, the area ratio of the blue region (AREA%) had the highest differential value, with an area under the curve (AUC) of 0.916 [95% confidence interval (CI): 0.812- 0.967], while sensitivity and specificity were 88.90% and 86.79%, respectively (p &lt; 0.05). Compared to RTE diffusion quantitative analysis parameters or TMs alone, the combination of the two showed the highest value for the differentiation of benign and malignant BNs, with an AUC of 0.957 (95% CI: 0.834-0.982), while sensitivity and specificity were 95.50% and 94.33%, respectively (p &lt; 0.05). Conclusion. RTE diffusion quantitative analysis combined with TMs has a high value for the differentiation of benign and malignant BNs.

Supershear Rayleigh wave imaging for quantitative assessment of biomechanical properties of brain using air-coupled optical coherence elastography.

Recently, supershear Rayleigh waves (SRWs) have been proposed to characterize the biomechanical properties of soft tissues. The SRWs propagate along the surface of the medium, unlike surface Rayleigh waves, SRWs propagate faster than bulk shear waves. However, their behavior and application in biological tissues is still elusive. In brain tissue elastography, shear waves combined with magnetic resonance elastography or ultrasound elastography are generally used to quantify the shear modulus, but high spatial resolution elasticity assessment in 10 μm scale is still improving. Here, we develop an air-coupled ultrasonic transducer for noncontact excitation of SRWs and Rayleigh waves in brain tissue, use optical coherent elastography (OCE) to detect, and reconstruct the SRW propagation process; in combing with a derived theoretical model of SRWs on a free boundary surface, we quantify the shear modulus of brain tissue with high spatial resolution. We first complete validation experiments using a homogeneous isotropic agar phantom, and the experimental results clearly show the SRW is 1.9649 times faster than the bulk shear waves. Furthermore, the propagation velocity of SRWs in both the frontal and parietal lobe regions of the brain is all 1.87 times faster than the bulk shear wave velocity. Finally, we evaluated the anisotropy in different brain regions, and the medulla oblongata region had the highest anisotropy index. Our study shows that the OCE system using the SRW model is a new potential approach for high-resolution assessment of the biomechanical properties of brain tissue.

The Clinical Value of Multimodal Ultrasound for the Differential Diagnosis of Hepatocellular Carcinoma from Other Liver Tumors in Relation to Histopathology.

Recent advances in the field of ultrasonography offer promising tools for the evaluation of liver tumors. We aim to assess the value of multimodal ultrasound in differentiating hepatocellular carcinomas (HCCs) from other liver lesions. We prospectively included 66 patients with 72 liver tumors. The histological analysis was the reference standard for the diagnosis of malignant liver lesions, and partially for benign tumors. All liver lesions were assessed by multiparametric ultrasound: standard ultrasound, contrast-enhanced ultrasound (CEUS), the point shear wave elastography (pSWE) using shear wave measurement (SWM) method and real-time tissue elastography (RTE). To diagnose HCCs, CEUS achieved a sensitivity, specificity, accuracy and positive predictive value (PPV) of 69.05%, 92.86%, 78.57% and 93.55%, respectively. The mean shear-wave velocity (Vs) value in HCCs was 1.59 ± 0.29 m/s, which was lower than non-HCC malignancies (p < 0.05). Using a cut-off value of 1.58 m/s, SWM achieved a sensitivity of 54.76%, and 82.35% specificity, for differentiating HCCs from other malignant lesions. The combination of SWM and CEUS showed higher sensitivity (79.55%) compared with each technique alone, while maintaining a high specificity (89.29%). In RTE, most HCCs (61.53%) had a mosaic pattern with dominant blue areas corresponding to type "c" elasticity. Elasticity type "c" was 70.59% predictive for HCCs. In conclusion, combining B-mode ultrasound, CEUS, pSWE and RTE can provide complementary diagnostic information and potentially decrease the requirements for other imaging modalities.

Effects of a 4 Week Cyclic Stretching Program on Muscle Stiffness and Hardness and Jump Performance in Healthy Adults: Preliminary Results of a Randomized Controlled Trial

Category: Sports; Ankle Introduction/Purpose: In general, Static Stretching (SS) is widely used during warm-ups and cool-downs at competitive practices and events. Previous studies have shown that SS have improved muscle stiffness. On the other hand, previous studies have not shown range of motion, or vertical jump. Recently, acute effects of Cyclic Stretching (CS) have suggested to improve muscle stiffness and dynamic balance. CS is moved at a constant speed and angle using continuous passive and dynamometer-equipped exercise equipment. However, long-term CS and SS programs have been shown to improve muscle stiffness, hardness, and It is not known if muscle strength or physical performance is altered. This study aimed to examine the effects of a 4-week CS and SS program on muscle stiffness and hardness, muscle strength, and jump performance. Methods: The subjects participated 18 healthy men and were randomly assigned to a CS or SS group. Each stretching program was stretched in each condition for 2 minutes in a standing position in 5 days a week for 4 weeks. To assess muscle stiffness, muscle- tendon junction (MTJ) displacement and MTJ angle of gastrocnemius medialis (MG) were measured using ultrasonography and 20° before (pre-training) and after (post-training) conducting CS and SS program. MG hardness was measured using ultrasound real- time tissue elastography (RTE). ROM max and normalized peak torque (NPT) of ankle plantar flexor, squat jump (SJ) performance were measured in the pre- and post-training. The effects of the intervention on all outcome measures were determined using 2- way repeated-measures ANOVA with two group as a between participants factor and time (pre-training, post-training) When interaction effects were detected, post hoc comparisons were performed to test the differences in physical variables between pre- and post-training. Results: ROM max was significantly affected by time between CS and SS program (P &lt; .001, F = 26.0). MTJ displacement from 0°to 20°were significantly affected by time (P &lt; .05, F = 5.49; P &lt; .01, F = 10.26; P &lt; .01, F = 9.74). RTE from 0°to 20°were significantly affected by time (P &lt; .01, F = 13.27; P &lt; .01, F = 8.33; P &lt; .01, F = 53.52). There was significantly interaction for NPT between CS and SS program (P &lt; .01, F = 4.80). SJ were significantly affected by time (P &lt; .05, F = 5.70). Conclusion: This study examined the long-term effect of CS and SS on ROM max, muscle stiffness, NPT, and SJ. The results indicate that CS training had greater improvement than SS training in muscle strength between pre- and post-training. A significant decrease in muscle stiffness and hardness after SS was observed compared with CS. However, CS not only improves muscle stiffness and hardness as shown the effect of SS but also suggests the possibility of being a new extension method to improve muscle strength.

A quantitative sonoelastography evaluation of ocular and periocular elasticity after intravitreal ranibizumab injection

We evaluated changes in ocular and periocular elasticity by ultrasound (US) elastography in intravitreal ranibizumab-treated eyes and the healthy fellow eyes of patients with neovascular AMD. The study was performed on 52 eyes of 26 volunteers who ranged in age from 59 to 89 (mean 72±7.78) years old. The study group consisted of the patients with neovascular AMD treated with intravitreal ranibizumab. The fellow eyes (without choroidal neovascularization) of the study group were selected as the control group. All patients were examined with sonoelastography before intravitreal injection and at 1day, 1week, and 1month after intravitreal injection. All images were acquired with a Toshiba Aplio 500 ultrasound system (Tokyo, Japan) including software with a combined autocorrelation method and a multifrequency linear probe. The elastography values of the anterior vitreous (AV), posterior vitreous (PV), retina-choroid-sclera complex (RCS), retrobulbar fat tissue (RF), optic nerve head (ONH) and retrobulbar optic nerve (RON) were measured in each eye. There were 13 male (50%) and 13 female (50%) participants in our study. Anterior vitreous, posterior vitreous, RCS, retrobulbar fat tissue, ONH, and RON US elastography values were similar in both groups (P˃0.05 for all). On the other hand, there was a positive correlation between the difference between baseline and 1-month PV sonoelastography values and age (r=0.47, P=0.035). A single dose intravitreal Ranibizumab (Lucentis®, Genentech, USA) injection does not alter the elasticity of ocular and periocular structures.

Could real-time sonoelastography-measured placental strain ratio (PSR) value be a soft marker for the diagnosis of intrahepatic cholestasis of pregnancy?: A case-control study and short reviews.

Diagnosis of intrahepatic cholestasis of pregnancy (ICP) is often decided upon with typical pruritus supported by elevated serum bile acid levels. However, there is confusion regarding the absolute reference range for serum bile acid . To confirm the utility of Placental Strain Ratio (PSR) measurement as a marker for the diagnosis of ICP and to reveal the extent to which it is correlated with serum bile acid concentration. A case-control study was conducted. The case group included 29 patients who were admitted to our hospital in the second or third trimester of pregnancy with typical itching and were clinically diagnosed with ICP with >10 mmol/L serum bile acid. The first 45 pregnant women were assigned to a control group. Real-time tissue elastography software was used for ultrasound assessment of all pregnant placentas. Software was used to estimate the SR values. Biochemical liver function parameters, hemograms, serum bile acid levels, and SR values were compared between these groups. PSR was found to predict the development of cholestasis with poor discrimination (area under the curve [AUC] = 0.524; 95% CI = 0.399-0.646). The optimal threshold value with the best sensitivity and specificity rates was calculated to be 0.46 PSR. ICP developed significantly more frequently in the low PSR group than in the high PSR group (60% vs 29.3%, P = .05, odds ratios [OR] = 0.276, 95% CI = 0.069-1.105). No correlation was found between the PSR and bile acid levels (rho = -0.029, P = .816). PSR values can support the diagnosis of ICP, predict serum bile acid levels, and can be used as soft markers.

Investigation of tongue hardness using ultrasound elastography in children during growth period

ABSTRACT Purpose Previous studies, the changes in tongue hardness with growth were scarcely ever described, but tongue pressure and morphology were the focus of them. Given that, we decided to use ultrasound to examine the changes in tongue hardness during growth. Materials and methods 60 paediatric patients (30 boys and 30 girls) aged 6 to 11 years (mean age, 8.5 ± 1.7 years) who visited the Department of Orthodontics, Showa University Dental Hospital were selected for the study. Tongue hardness was measured using real-time ultrasound tissue elastography. The measured values of tongue elasticity were subjected to the Shapiro – Wilk test, and QQ plot for checking the normality. Pearson’s correlation coefficient was used to confirm the significance of the relationship among the three measurements of tongue elasticity, age, sex, height, weight, BMI, body fat, tongue pressure, and hand strength. Results We confirmed that the use of ultrasound SWE and SE are valuable for the measurement of tongue elasticity. A negative correlation between age and tongue elasticity SE (extraoral) (r = −0.26, P < 0.05), body weight and tongue elasticity SE (extraoral) (r = −0.30, P =＜0.05). Conclusion It was suggested that tongue hardness changes with changes with age. The balance between the tongue and perioral muscles is affected with the position of the teeth. Perioral muscle function is closely associated with malocclusion onset, particularly during childhood when maxillofacial growth and development are rapid. Therefore, the use of ultrasonography device can aid in the evaluation of treatments to improve perioral muscle function.

Determination of the reference range for semi-quantified elasticity of healthy supraspinatus muscles using real-time tissue elastography and its clinical use in patients after rotator cuff repair

BackgroundThe quantitative assessment of healthy supraspinatus muscle elasticity may provide clinically useful preliminary information after rotator cuff repairs. We aimed to determine the reference range for supraspinatus muscle semi-quantified elasticity and describe how it can be used clinically after rotator cuff repair. MethodsThe elasticity of healthy bilateral supraspinatus muscles in 43 participants aged between 24 and 75 years (categorized into two subgroups: <50 and ≥ 50 years) was measured as a strain ratio at 0° and 60° of shoulder abduction using real-time tissue elastography. The reference and modified reference ranges calculated by excluding outliers for elasticity were determined using normal distribution methods for logarithmically transformed data. The modified reference range was applied to eight cases of rotator cuff repair. FindingsStrain ratios under and over 50 years of age were 1.63 vs. 2.21 at 0° of shoulder abduction (P = 0.028) and 0.92 vs. 1.29 at 60° of shoulder abduction (P = 0.002), respectively. Modified reference ranges for under and over 50 years of age were 0.72–4.17 and 0.98–4.50 at 0° of shoulder abduction and 0.38–1.95 and 0.56–2.76 at 60° of shoulder abduction, respectively. Among eight cases, two showed strain ratios above the reference range at 1 month postoperatively, and rehabilitation protocols were adjusted. InterpretationA strain ratio above the reference range, especially above the upper limit at 0° of shoulder abduction, may indicate increased passive stiffness of the musculotendinous unit. Clinically, the reference range has the potential to be used as a baseline after rotator cuff repairs.

Comparative Study of Muscle Hardness during Water-Walking and Land-Walking Using Ultrasound Real-Time Tissue Elastography in Healthy Young People

Compared with land-walking, water-walking is considered to be beneficial as a whole-body exercise because of the characteristics of water (buoyancy, viscosity, hydrostatic pressure, and water temperature). However, there are few reports on the effects of exercise in water on muscles, and there is no standard qualitative assessment method for muscle flexibility. Therefore, we used ultrasound real-time tissue elastography (RTE) to compare muscle hardness after water-walking and land-walking. Participants were 15 healthy young adult males (24.8 ± 2.3 years). The method consisted of land-walking and water-walking for 20 min on separate days. The strain ratio of the rectus femoris (RF) and medial head of gastrocnemius (MHGM) muscles were measured before and immediately after walking using RTE to evaluate muscle hardness. In water-walking, the strain ratio significantly decreased immediately after water-walking, with p < 0.01 for RF and p < 0.05 for MHGM, indicating a significant decrease in muscle hardness after water-walking. On the other hand, land-walking did not produce significant differences in RF and MHGM. Muscle hardness after aerobic exercise, as assessed by RTE, was not changed by land walking but was significantly decreased by water walking. The decrease in muscle hardness induced by water-walking was thought to be caused by the edema reduction effect produced by buoyancy and hydrostatic pressure.

A Review about C-TIRADS, ACR-TIRADS, and K-TIRADS Combined with Real-Time Tissue Elastography to Diagnose Thyroid Nodules.

This study aimed to evaluate the diagnostic efficiency of the Chinese version of thyroid imaging reporting and data system (C-TIRADS), American College of Radiology (ACR)-TIRADS, and Korean (K)-TIRADS combined with real-time tissue elastography to diagnose thyroid nodules. A total of 574 thyroid nodule ultrasonographic images were retrospectively analyzed and classified based on the three TIRADS methods. The MedCale statistical software was used to construct the receiver operating characteristic (ROC) curve based on the pathological results of surgery. The diagnostic efficiency before and after assessing elastographies from the three TIRADS was compared between C-TIRADS, ACR-TIRADS, and K-TIRADS groups and within before and after TIRADS combined with elastic imaging. Furthermore, the unnecessary biopsy rates were also compared. Comparing area under ROC curve (AUC) with MEDCALC software (20.0.15, MedCalc Software Ltd., Ostend, Belgium), Delong test was used. The sensitivity and specificity were compared by STATA software (15.1, StataCorp LP, College Station, TX, USA) and Chi-square test. The rate of unnecessary biopsy was compared by SPSS software (23.0, IBM, Armonk, NY, USA) and Chi-square test. C-TIRADS, ACR-TIRADS, K-TIRADS cut-off values, and real-time tissue elastography (RTE) were 4b, 5, 5, and 3, respectively, and the areas under the ROC curve were 0.932, 0.914, 0.904, and 0.883, respectively. C-TIRADS had the highest AUC (p < 0.05) and sensitivity (p < 0.001), while ACR-TIRADS had the highest specificity (p < 0.001). After conducting a combined elastography with the three TIRADS, AUC showed increases of different degrees. Comparing TIRADS with TIRADS+RTE, the difference of C-TIRADS had statistical significance (p < 0.001), but the difference of ACR-TIRADS and K-TIRADS had no statistical significance (p > 0.05). The unnecessary biopsy rate showed decreases of different degrees. Differences between C-TIRADS and K-TIRADS were significant (p < 0.05), but in the case of ACR-TIRADS were not significant (p > 0.05). C-TIRADS, ACR-TIRADS, K-TIRA and RTE showed high diagnostic efficiency, with C-TIRADS having the highest. Real-time tissue elastography can improve TIRADS diagnostic efficiency and reduce its unnecessary biopsy rate. In this case C-TIRADS showed again the highest efficiency.

The Performance of the Uterine Artery Resistance Index following Stimulation of the Cervix in the Diagnosis of Endometriosis: A Prospective Study

Background: We speculated that stimulating the uterine cervix of patients may increase blood flow resistance of the uterine artery more significantly in women with endometriosis than those without. Accordingly, the resistance index (RI) of the uterine artery following stimulation of the cervix may offer a novel and promising non-invasive method for diagnosing endometriosis. In this prospective study, the aim was to determine the performance of the uterine artery resistance index (RI) following stimulation of the cervix in the diagnosis of endometriosis. Methods: This prospective cohort study included 270 patients with non-uterine diseases who were scheduled for laparoscopic surgery. Each patient underwent Doppler sonography for peak systolic velocity (PSV), end diastolic velocity (EDV), and RI before and after stimulation of the cervix, in addition to conventional ultrasound examination one day prior to laparoscopic surgery. The cervix was stimulated using a double convex array electronic vaginal probe for real-time tissue elastography. Results: Laparoscopic surgical evaluation revealed endometriosis in 91 (33.7%) patients. Following stimulation of the cervix, the RI of the uterine artery was significantly increased in the endometriosis group (p = 0.00), but no significant increase in the RI was observed in the control group (p = 0.45). The sensitivity and specificity of the post-stimulation RI for diagnosing endometriosis (using a cut off of 0.83) were 85.71% (95% confidence interval (CI): 76.45–91.88) and 88.83% (95% CI: 83.05–92.87), respectively. For peritoneal endometriosis (PEM), sensitivity and specificity were 86.96% (95% CI: 65.33–96.57) and 88.83% (95% CI: 83.05–92.87), respectively. The sensitivity and specificity of transvaginal ultrasonography (TVU) for diagnosing endometriosis were 63.74% (95% CI: 52.93–73.37) and 94.41% (95% CI: 89.68–97.14), respectively. The positive rate for TVU in diagnosing all endometrioses was 63.7%, and this was lower than that for the post-stimulation RI (84.6%, p = 0.001). Conclusions: Stimulation of the cervix leads to a significant decrease in uterine blood perfusion in women with endometriosis. TVU is a sensitive and specific method for the diagnosis of endometrioma, while the RI is a more sensitive parameter for diagnosing PEM than TVU. For the diagnosis of endometriosis, especially for PEM, the post-stimulation RI may prove to be a promising non-invasive diagnostic technique.

Inter-operator and inter-device reproducibility of shear wave elastography in healthy muscle tissues.

PurposeThe study aimed to assess whether the more limiting factor in reproducibility of shear wave elastography (SWE) would be the operator dependency or the incompatibility of different ultrasound (US) devices. The interrater agreement with less experienced operators was studied.MethodsA total of 24 healthy volunteers participated in the study (18 females, 6 males; range of age 27–55 years). SWE of biceps brachii (BB) and tibialis anterior (TA) muscles was performed on both sides from all participants in both longitudinal and transverse orientation of the transducer in respect to muscle fibers. Two operators repeated the SWE with two different US devices from different manufacturers (scanners 1 and 2).ResultsIntraclass correlation coefficient between the two operators was 0.91 (CI 0.88–0.93) for scanner 1 and 0.81 (CI 0.74–0.86) for scanner 2, respectively. Instead, there were significant differences in the SWE measurements between the two scanners, emphasizing in transverse orientation of the transducer. In the transverse transducer orientation, the mean shear wave velocity (SWV) in TA was 1.45 m/s (standard deviation [SD] ± 0.35 m/s) with scanner 1 and 2.35 m/s (SD ± 0.83 m/s) with scanner 2 (p < 0.001). In BB, the mean transverse SWV was 1.49 m/s (SD ± 0.35 m/s) with scanner 1 and 2.29 m/s (SD ± 0.63 m/s) with scanner 2 (p < 0.001). In longitudinal transducer orientation, the mean SWV in TA was 3.00 m/s (SD ± 0.73 m/s) with scanner 1 and 3.26 m/s (SD ± 0.42 m/s) with scanner 2 (p = 0.050). In BB, the mean longitudinal SWV was 3.60 m/s (SD ± 0.77 m/s) with scanner 1 and 3.96 m/s (SD ± 0.62 m/s) with scanner 2 (p = 0.019). The presented mean values were obtained by operator 1, there were no significant differences in the SWE measurements performed by the two operators.ConclusionThe results implicate that the reproducibility of the SWE measurements depends rather on the used US device than on the operator. It is recommendable that clinics collect reference values with their own US device and consider threshold values presented in previous studies only directional.

Evaluation of pelvic floor muscle elasticity in patients with overactive bladder syndrome using real-time tissue elastography

Introduction and hypothesisThe purpose of this study was to compare the muscle elasticity of the striated urethral sphincter (SUS) using real-time tissue elastography (RTE) as an evaluation of pelvic floor muscle (PFM) function between overactive bladder (OAB) patients and healthy women. MethodsThe subjects were 8 healthy middle-aged women (healthy group; age range 57–65 years) and 9 female OAB patients (OAB group; age range 42–80 years). The target sites of elastography were the striated urethral sphincter (SUS) and adipose tissue as the reference site; muscle elasticity was calculated as the strain ratio (SR) of the SUS to the reference site. Evaluations were performed at rest and during PFM contraction. The OAB group completed OAB symptom and quality of life questionnaires. The SUS SR was compared between the groups. The SUS SR at rest and during PFM contraction was compared within groups using the t-test and Wilcoxon’s test. The relationship between the questionnaire results and the SUS SR was evaluated by correlation analysis. ResultsIntergroup comparisons between the healthy and OAB groups showed no significant differences in SUS SR at rest and during PFM contraction. On intragroup comparisons, the SUS SR was significantly higher during PFM contraction than at rest in the healthy group (p = 0.011); in the OAB group, there was no significant difference in the SUS SR between rest and PFM contraction. The SUS SR was not significantly correlated with questionnaire results for OAB symptoms. ConclusionThis study shows the potential to non-invasively confirm the inability of OAB patients to correctly perform PFM contraction using RTE.

Combinational elastography for assessment of liver fibrosis in patients with liver injury.

ObjectiveWe investigated the utility of combinational elastography with point shear wave elastography (pSWE) and real-time tissue elastography (RTE) for evaluating liver fibrosis in patients with liver injury.MethodsIn this prospective single-institution study, patients scheduled for a liver biopsy to determine the presence of liver disease were enrolled. Liver fibrosis in each patient was evaluated using both shear wave velocity (Vs) shown by pSWE and the liver fibrosis index (LFI) shown by RTE, while a liver biopsy sample was obtained from the same area that was subjected to an elastography examination. Results of the latter were compared with those obtained in a histological examination.ResultsMultivariate analysis showed that Vs and LFI were significantly correlated with the liver fibrosis stage in all of the enrolled patients. Sub-analysis findings compared patients with and without non-alcoholic fatty liver disease (NAFLD) and demonstrated that Vs was significantly correlated with the liver fibrosis stage in both groups, whereas LFI was correlated with that only in the non-NAFLD patients. However, a multivariate analysis demonstrated a significant correlation between steatosis grade and LFI in the NAFLD patients.ConclusionsRTE is less useful than pSWE for assessing liver fibrosis in patients with NAFLD.

A stability result for the identification of a permeability parameter on Navier–Stokes equations

In this work, we present a stability result for the inverse problem of recovering a smooth scalar permeability parameter given by the Brinkman’s law applied to the steady Navier–Stokes equations from local observations of the fluid velocity on a fixed domain. In comparison with (Choulli et al 2013 Appl. Anal. 92 2127–43), we prove a logarithmic estimate under weaker assumptions, since our proof is based in a strategy that does not require pressure observations. This kind or result are useful for inverse problems in soft tissue elastography (see Honarvar et al 2012 Phys. Med. Biol. 57 5909–27). Finally, we present some numerical tests that validate our theoretical results.