Strain Ratio Values Research Articles

Diagnostic Value of Elastography, Strain Ratio, and Elasticity to B-Mode Ratio and Color Doppler Ultrasonography in Breast Lesions.

PurposeThe aim of this study was to investigate the sensitivity, specificity, and diagnostic accuracy of sonoelastography (SE), strain ratio (SR), elasticity to B-mode (E/B) ratio, and color Doppler ultrasonography (US) in suspected breast lesions.Materials and MethodsThis prospective study was conducted on women referred to Alzahra university hospital of Tabriz for annual screening of breast cancer between May 2017 and December 2018. B-mode US, SE, and color Doppler imaging were conducted in females with suspected mammography reports. The lesions in B-mode were classified according to the Breast Imaging Reporting and Data System (B-RADS). The results of SE imaging were graded based on five-grade SE score. SR and E/B ratio of each lesion were also analyzed in SE images. Color Doppler findings were categorized from 0 (no visible vessel) to 2 (> two vessels) based on the vascularity of the tumor. Pathology results were used as the gold standard to measure the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and diagnostic accuracy of each modality.ResultsOne-hundred and ten breast lesions of 104 women aged 42.05±10.33 years were included in the study. Seventy-seven of the lesions were benign and 3 were malignant. Sensitivity and specificity of 97.0% and 77.9% for B-mode US, 93.9% and 87.0% for SE score, 81.8% and 66.2% for color Doppler US, 72.7% and 77.6% for E/B ratio (cutoff: 1.05), and 77.3% and 79.6% for SR (cutoff: 1.90) were obtained, respectively. Addition of SE score to B-mode US increased the sensitivity to 93.9%, specificity to 93.5%, and AUC from 0.95 to 0.97. Cumulative color Doppler US with B-mode US did not enhance the diagnostic accuracy of B-mode US.ConclusionSE was more effective than color Doppler US for distinguishing malignant from benign breast lesion. Among the three different SE features, five-grade SE score was superior to E/B ratio and SR.

Partially cystic thyroid cancer on conventional and elastographic ultrasound: a retrospective study and a machine learning-assisted system.

BackgroundThyroid carcinoma constitutes the vast majority of all thyroid cancer, most of which is the solid nodule type. No previous studies have examined combining both conventional and elastic sonography to evaluate the diagnostic performance of partially cystic thyroid cancer (PCTC). This retrospective study was designed to evaluate differentiation of PCTC from benign partially cystic nodules with a machine learning–assisted system based on ultrasound (US) and elastography.MethodsPatients with suspicious partially cystic nodules and finally confirmed were included in the study. We performed conventional US and real-time elastography (RTE). The US features of nodules were recorded. The data set was entered into 6 machine-learning algorithms. Sensitivity, specificity, accuracy, and area under the curve (AUC) were calculated.ResultsA total of 177 nodules were included in this study. Among these nodules, 81 were malignant and 96 were benign. Wreath-shaped feature, micro-calcification, and strain ratio (SR) value were the most important imaging features in differential diagnosis. The random forest classifier was the best diagnostic model.ConclusionsUS features of PCTC exhibited unique characteristics. Wreath-shaped partially cystic nodules, especially with the appearance of micro-calcifications and larger SR value, are more likely to be malignant. The random forest classifier might be useful to diagnose PCTC.

TI-RADS Diagnostic Performance: Which Algorithm is Superior and How Elastography and 4D Vascularity Improve the Malignancy Risk Assessment.

Given the increased prevalence of thyroid nodules in the general population (~50%), the real challenge resides in correctly recognizing the suspicious ones. This study proposes to compare four important Thyroid Imaging and Reporting Data Systems (TI-RADS) and evaluate the contribution of elastography and 4D Color Doppler assessment of vascularity in estimating the risk of malignancy. In the study, 133 nodules with histopathological examination were included. Of these, 35 (26.31%) proved to be malignant. All nodules were classified using the four selected systems and our proposed improved score. The American College of Radiology (ACR) and EU TI-RADS had good sensitivity (94.28%, 97.14%) and NPV (93.33%, 95.83%), but fairly poor specificity (31.81%, 23.46%) and PPV (35.48%, 31.19%), with an accuracy of 42.8% and 45.8%, respectively. Horvath TI-RADS had better accuracy of 66.9% and somewhat improved specificity (62.24%), but poorer sensitivity (80%). Russ’ French TI-RADS includes elastography in the risk assessment strategy. This classification proved superior in all aspects (Se: 91.42%, Sp:82.65%, NPV:96.42%, PPV:65.30%, and Acc of 84.96%). The mean strain ratio (SR) value for malignant lesions was 5.56, while the mean SR value for benign ones was significantly lower, 2.54 (p < 0.05). It also correlated well with the response variable: histopathological result (p < 0.001). Although, adding 4D vascularity to the French score generated a similar calculated accuracy and from a statistical point of view, the parameter itself proved beneficial for predicting the malignancy risk (p < 0.001) and may add important knowledge in uncertain situations. Advanced ultrasound techniques definitely improved the risk estimation and should be used more extensively.

Noninvasive assesment in differentiating benign and malign pancreatic lesions with endosonographic elastography score and strain ratio

Background: We aimed to evaluate the diagnostic capability of endoscopic ultrasound elastography (EUS-EG) and strain ratio (SR) for differentiating benign pancreatic lesions from the malign lesions Material and Method: We retrospectively evaluated well collected data of patients who undergone EUS-EG in a single centre during the period of January 2016-June 2019. Patients who had pancreatic disorders were further evaluated for the study. The final diagnosis of solid pancreatic lesions (SPL) was made by histopathologic examination. Control group consisted of patients with chronic pancreatitis (CP) who diagnosed according to Rosemont criteria. Elastography was evaluated by a qualitative (elastography scores) and a quantitative method SR. Results: A total of 66 patients (42 (63.6%)female/42 (63.6%)male) with mean age of 58.88±15.32 (19- 80) were included in the study. Thirty-eight patients had SLP, remain 28 patients were CP. In SPL group, 32 (84.2%) had adenocarcinomas and 6 (15.8%) had neuroendocrine tumors. Among 28 patients with benign pancreatic lessions, 23 (82.1%) had CP while five (17.9%) had autoimmune pancreatitis. Median SR values were significantly higher in patients with SPL than those with CP (44.0 (10.0-110.0) vs 7.0 (2.6-14.6), p&amp;lt;0.001). Elasticity scores were also significantly different between patients with SLP and CP (p&amp;lt;0.001). Elasticity scores were significantly different between adenocarcinomas and CP (p&amp;lt;0.001). A 14 cut-off value of SR had 97% sensitive and 100% specificity for SPL and receiver-operating characteristic curves showed an area under the curve of 0.99.6. Likelihood Ratio test revealed that SR appears as the best parameter in discrimination of lesion type either as benign or malignant (X2 = 54.031, p&amp;lt;0.001). Conclusion: Our study suggested that EUS-elastography and SR scores are highly effective in differentiating malign-benign pancreatitis lesions

Combination diagnosis with elastography strain ratio and molecular markers effectively improves the diagnosis rate of small breast cancer and lymph node metastasis.

To evaluate the strain ratio (SR) combined with molecular pathological and serum markers for the diagnosis of breast masses. SR and 7-point scale elasticity scores were used with real-time tissue elastography and 2-dimensional color-Doppler ultrasound (US) to diagnose breast lesions in 311 hospitalized patients. Immunohistochemical staining and enzyme-linked immunosorbent assays (ELISAs) were used to examine pathological and serum tumor markers and their correlations with SR findings. SR had a higher diagnostic value compared to the 7-point scale elasticity score, displaying an obvious low-to-high distribution from benign to malignant lesions with an optimal cutoff point at 3.88, which yielded an area under the curve (AUC) of 0.896 with 89.1% sensitivity, 85.6% specificity, and positive and negative predictive values of 91.0% and 82.8%, respectively. The differences of SR values between small (≤1.5 cm), large (>3 cm) (P=0.010), and moderate (>1.5 cm and ≤3 cm) sizes (P=0.038) in distinguishing benign from malignant breast masses were statistically significant, with SR being most specific and sensitive for diagnosing small lesions. Expression of 3 molecular pathological indicators (p75NTR, p63, and CK5/6), and 5 serum mastocarcinoma markers (uPA, PAI-I, CA27-29, CEA, and CA15-3) showed statistical significance (P<0.05) in distinguishing between benign and malignant breast lesions. Furthermore, SR combined with CA15-3 and CK5/6 positivity showed 94.2% sensitivity and 89.2% specificity as combined markers for triple-negative (TN) breast cancer, whereas SR combined with D2-40 and CK19 were good diagnostic markers for breast cancer lymph node metastasis. SR, together with a molecular and serological marker, may serve as an additional tool for the diagnosis of small breast cancer tumors.

Renal Medulla and Cortex Strain Elastography in Healthy Individuals

Kidney diseases are a common illness in worldwide. Many invasive and non-invasive methods are used to detect renal disease. Ultrasonic elastography (UE) is one of these techniques and a relatively new one. In this study, it is intended to determine whether is there a difference between medulla and cortex strain Ratio (SR) values in healthy individuals without renal disease. The study recruited 74 normal volunteers (26 males, 48 female subjects) with an average age of 43.46 ± 14.65 years (18-76). The SR values between the cortex and the medulla p value was 0,052. There was no significant difference between cortex and medulla SR values. There is no significant difference between the medulla and cortex values of healthy individuals who have undergone strain elastography, suggesting that the results of these studies are even more valuable.

REAL TİME ELASTOGRAFİNİN ETKİNLİĞİ: KORTİKOMEDÜLLER STRAİN ORANI ÜRİNER OBSTRÜKSİYONUN TANI VE TAKİBİNDE KULLANILABİLİR Mİ?

Aim: To investigate the utility of corticomedullary strain ratio (SR) in the diagnosis and follow-up of urinary obstruction Material and Methods: Forty volunteer patients (26 males, 14 females) aged between 18-60 years, who were admitted to our outpatient urology clinic with renal colic due to stone and diagnosed as unilateral urinary tract obstruction via CT, were included in the study. Contralateral intact kidneys of the same patients were accepted as control group. The age, gender, duration of renal colic, blood pressure and BMI of the all patients were also recorded. Patients were examined with renal ultrasonography, doppler ultrasonography and Real Time Elastography (RTE) by a single radiologist with 8 years of experience in abdominal radiology. The average of these three measurements was used in statistical analysis. Strain ratio (SR) was measured by marking the region of interest in the medulla and cortex determined in B mode during the decompression phase. Results: No difference was observed in terms of age between the groups. We found a positive correlation between renal pelvic diameter and RI in obstructed kidney (p=0.006 ve r=0.446). There was a statistically significant difference between mean corticomedullary SR values of hydronephrotic kidneys (0.38 ± 0.43) and mean SR values of contralateral intact kidneys (0.61 ± 0.69) (p=0.025). Also, we observed statistically significant difference between the mean arterial doppler values of the hydronephrotic kidneys (0.64 ± 0.06) and the arterial doppler values of intact kidneys (0.60 ± 0.05) (p=0.026). Conclusion: The measurement of renal corticomedullary SR by RTE, which is a noninvasive method, can be used in the diagnosis and follow-up of urinary obstruction. This finding is supported by increased arterial RI data in urinary obstruction described in the literature.

Diaphragm thickness and stiffness in patients with hyperkyphosis due to osteoporotic vertebral fracture: an ultrasonographic and elastographic study.

PurposeThe objective of this study was to evaluate the thickness and stiffness of the diaphragm, using ultrasound (US) and strain elastography (SE) in patients with hyperkyphosis due to osteoporotic vertebral fracture.Material and methodsThis prospective and case-control study was conducted between October 2019 and December 2019. Diaphragm thickness, SE, and strain ratio values of patients with hyperkyphosis due to osteoporotic vertebral fracture were compared with those of the control group.ResultsThere were 42 patients (14 males, 28 females) with a mean age of 81.10 ± 6.3 years in the kyphosis group and 36 subjects (11 males, 25 females) with a mean age of 81.00 ± 5.5 years in the control group. End-inspirium thickness, change level, and thickening ratio of the diaphragm were significantly higher in the control group (p < 0.001 for all). Strain ratio values were significantly higher in the kyphosis group, and the rate of hardest colour code was significantly higher in the control group. The diaphragm thickness at end-inspirium and thickening ratio values correlated positively with the forced expiratory volume in the first second (FEV1, %) and forced vital capacity (FVC, %) values. The strain ratio values correlated inversely with the FEV1 (%) and FVC (%) values. The diaphragm thickness at end-inspirium and thickening ratio values correlated inversely with the Cobb values and number of vertebra fractures. A positive correlation was determined between the strain ratio values and the Cobb values and number of vertebra fractures.ConclusionsUltrasonography is a promising imaging tool to evaluate and quantify the diaphragm function and stiffness in relevant patients.

Interacting Factors of Strain Ratio Values in Fibroadenomas and the Contribution of Color Scale.

Background:The purpose of this retrospective study is to investigate the association of qualitative and semiquantitative strain elastography (SE) features with factors such as lesion size, skin-to-lesion distance, and patient's age in fibroadenomas and to discuss false-positive results.Methods:A total of 120 lesions that were performed SE with histopathologically confirmed fibroadenoma were included in the study. All images were reviewed from the archiving system with a consensus of two radiologists. Tsukuba elasticity score was used for color scoring (from 1 to 5). Lesions with strain ratio (SR) ≥2.27 and color scale score of 4 or 5 were considered as false positive. The patients were divided into two groups according to the age: <50 and ≥50 years old. Regard of the size, lesions were divided into two groups: <15 mm and ≥15 mm. The distances of the lesions to the skin were also divided into two groups: <5 mm and ≥5 mm. Statistical analysis to identify associations between these groups and SR was carried out with Pearson Chi-square test and Fisher's exact test. The false-positive rates were calculated.Results:There was no statistically significant difference between patients' age, lesion size, skin-to-lesion distance, and SR values. The false-positive rate was 21.66% for SR, while it was 3.33% for color scale.Conclusion:SR values of the fibroadenomas were not affected by factors such as age, lesion size, and depth. In addition, false-positive rates significantly decrease when color scale scores are evaluated for fibroadenomas.

Levator ani evaluation at transperineal elastography in women with deep infiltrating endometriosis postoperatively

ObjectiveTo explore whether operation can change the elasticity of levator ani in deep infiltrating endometriosis (DIE) with operation and pharmacotherapy using transperineal elastography. MethodsTotal thirty-four patients who were diagnosed as DIE were included in the study. Transperineal elastography were performed in all cases preoperatively and postoperatively. The levator ani was evaluated by means of the scoring system and strain ratio (SR) values on maximal Valsalva and quiescent condition, respectively. ResultsOn quiescent condition, the preoperative mean elastography scores and SR of the levator ani were statistically significantly higher than the postoperative ones in both shaving technique group and segmental colorectal resection group. And on maximal Valsalva, the preoperative mean elastography scores and SR of the levator ani were statistically significantly lower than the postoperative ones in both groups. After surgery and 6 cycles of GnRHa therapy, the mean elastography score and SR of the levator ani were statistically significantly lower than before GnRHa therapy in shaving technique group on quiescent condition. And on maximal Valsalva, the mean elastography score and SR were statistically higher than before GnRHa therapy. However, in segmental colorectal resection group, the differences were not observed before and following 6 cycles of GnRHa therapy. ConclusionThe elasticity of levator ani of DIE was changed by both shaving technique and segmental colorectal resection. And transperineal elastography could access the alterations.

Elastosonographic evaluation after extracorporeal shockwave treatment in plantar fasciopathy.

To assess the ultrasound features in patients with plantar fasciopathy before and after extracorporeal shock waves therapy (ESWT), using conventional grey-scale imaging and both strain (SE) and shear wave (SWE) elastosonographic evaluation. Consecutive patients of both sexes attending our outpatient's clinic, with diagnosis of unilateral plantar fasciopathy, were enrolled. Patients were treated with 3 sessions of ESWT once a week, and underwent clinical and ultrasound evaluation at baseline and at one and three months after treatment. Roles and Maudsley score (RM), visual analog scale (VAS) and 17-Italian Foot Function Index (FFI), were used to assess pain and functional improvement. Twenty patients (11 female and 9 male) were enrolled in the study. Contralateral asymptomatic healthy plantar fascia was used as a control. At baseline, SWE velocity (SWEv) showed statistically significant difference between affected 3.8 (1.5; 5.1) m/s and healthy side 4.7 (4.07; 7.04) m/s, (p=0.006); no significant difference was found for strain ratio values (p=0.656). SWEv post hoc test results showed a significant difference from baseline 3.8 (1.5-5.1) m/s and three month 5.23 (4.55-6.74) m/s follow up visit (p=0.003). Significant statistical negative correlation was found between the SWEv and VAS (p=0.001) and positive correlation between the SWEv and FFI (p=0.012). SWE was effective in assessing plantar fascia elasticity and its alteration in fasciopathy. Furthermore, on the basis of the correlation with pain and functional scales, this technique appears to be a useful additional technique to conventional ultrasound for monitoring the efficacy of treatment.

Nipple Deformation and Peripheral Pressure on the Areola During Breastfeeding.

Breastfeeding is a complex process where the infant utilizes two forms of pressure during suckling, vacuum and compression. Infant applied compression, or positive oral pressure, to the breast has not been previously studied in vivo. The goal of this study is to use a methodology to capture the positive oral pressure values exerted by infants' maxilla (upper jaw) and mandible (lower jaw) on the breast areola during breastfeeding. In this study, the positive and negative (vacuum) pressure values are obtained simultaneously on six lactating mothers. Parallel to the pressure data measurements, ultrasound images are captured and processed to reveal the nipple deformations and the displacements of infants' tongues and jaw movements during breastfeeding. Motivated by the significant differences in composition between the tissue of the breast and the nipple-areola complex, the strain ratio values of the lactating nipples are obtained using these deformation measurements along with pre- and postfeed three-dimensional (3D) scans of the breast. The findings show an oscillatory positive pressure profile on the breast under both maxilla and mandible, which differs from clinical indications that only the mandible of an infant moves during breastfeeding. The strain ratio varies between mothers, which indicates volume changes in the nipple during feeding and suggests that previous assumptions regarding strain ratio for nonlactating breasts will not accurately apply to breast tissue during lactation.

Monitoring symptom improvements after the treatment of active myofascial trigger points with ultrasound elastography

Purpose: Ultrasound elastography (UE) is a recently developed technique and is used to determine the mechanical properties of tissues. We aimed to assess the usefulness of axial-strain UE for pre and post treatment evaluation of patients with active myofascial triggerpoints (MTrPs) of the upper trapezius.Materials and Methods: The study included 49 patients (66 MTrPs) with myofascial pain syndrome. Patients were randomized into two treatment groups, group 1 (trigger point injection with stretching exercises) and group 2 (trigger point injection). The groups were evaluated with UE before, 2 and 14 days post-treatment. Disability, pain, and pressure pain threshold (PPT) were also assessed. Results: All clinical parameters were strongly correlated with strain ratio (SR) value at baseline, 2 and 14 days post-treatment. Both groups demonstrated significant improvements with respect to Neck Pain and Disability Scale , VAS, and PPT scores post-treatment. However, group 1 had better scores than group 2 in 14 days post-treatment. Conclusion: Our study demonstrated that SR values for MTrPs in the upper trapezius correlated with clinical parameters at baseline and after treatment. According to these results, axial-strain UE, which is non-invasive and semiquantitative method may be usefull to evaluation and monitor improvement in patients with active MTrPs.

Physical Modelling and Numerical Simulation of the Deep Drawing Process of a Box-Shaped Product Focused on Material Limits Determination

Similitude theory helps engineers and scientists to accurately predict the behaviors of real systems through the application of scaling laws to the experimental results of a scale model related to the real system by similarity conditions. The theory was applied when studying the deep drawing process of a bathtub made from cold rolled low carbon aluminum-killed steel from the point of view of material limits. The bathtub model was created on the basis of geometric, physical, and mechanical similarity on a scale of 1:5. Thus, simulations and physical models were created. The simulation model was used to verify the combination yield locus/hardening law on the basis of comparing the thickness change. As a result, Hill 48/Krupkowski showed the minimal deviation by comparing data evaluated from numerical simulations and that measured on the physical model. Additionally, material anisotropy was modelled when virtual materials were defined from experimentally measured values of the plastic strain ratio. As an outcome, extra deep drawing quality steel with an average plastic strain ratio of rm ≥ 1.47 and an average strain hardening exponent of nm ≥ 0.23 must be used for the deep drawing of the bathtub.

The Evaluation of Benign Acute Childhood Myositis by Ultrasound Elastography

Objective: Herein, we aimed to determine the diagnostic contribution of ultrasound elastography (UE) technique to the assessment of muscle stiffness in pediatric patients with myositis.&#x0D; Material and Methods: This study enrolled 16 patients who presented to our hospital’s Pediatric Neurology Outpatient Clinic with the complaint of inability to walk and who had a clinical presentation of benign acute childhood myositis (BACM). The patients were referred to the Radiology Department to undergo muscle ultrasonography (USG), where they underwent UE of the gastrocnemius muscle (GCM).&#x0D; Results: Children with myositis and healthy children are similar age (7.06 ± 1.52 year (5–11) vs. 7.00 ± 1.59 year (5–11) year) (P: 0.908) and body mass index (BMI) (20.04 ± 1.58 (18.6–24.2) vs. 22.08 ± 1.43 (19.9–24.4) (P: 0.946). The mean serum creatine kinase (CK) was measured as 1520.3 ± 1163.6 U/L (min: 456, max:4100) in children with myositis. In the children with myositis, the thickness of the medial and lateral GCM increased compared with that in control group (medial; 18.15 ± 3.02 mm vs 13.10 ± 2.26 mm, p&lt;0.001, lateral; 13.51 ± 3.07 mm vs 9.34 ± 1.86 mm, p&lt;0.001). The medial and lateral GCM ratio in group 1 was slight bigger than that in group 2 (medial; 1.10 ± 0.37 vs 1.00 ± 0.34, p: 0.274, lateral; 1.22 ± 0.44 vs 1.10 ± 0.29, p: 0.243). GCM strain values were mildly elevated in patients with myositis compared to controls.&#x0D; Conclusion: In the children with myositis, the thickness of the medial and lateral GCM increased compared with that in control group. GCM strain ratio values were slightly higher in myositis patients compared to the control group. We think that the increase in muscle thickness values is mainly secondary to the edema seen in myositis. In addition, UE is a clinically applicable quantitative analysis for changes in myositis.

Effect of strain ratio on cyclic deformation behaviour of 7050-T6 aluminium alloy

This paper aims at investigating the strain ratio effect on cyclic deformation behaviour of 7050-T6 aluminium alloy. Low-cycle fatigue tests are conducted under strain-controlled conditions at three strain ratios (−1, 0, and 0.5) with strain amplitudes in the range 0.60–1.75%. Microstructure is analysed by optical microscopy, transmission electron microscopy and X-ray diffraction, and fracture surfaces are examined by scanning electron microscopy and transmission electron microscopy. The results show that the material exhibits a cyclic strain-softening behaviour whose degree increases with increasing values of strain ratio and decreasing values of strain amplitude. Under non-zero mean strain, full relaxation of mean stress is only observed at higher strain amplitudes. A second order logarithmic model is proposed to account for the mean stress relaxation rates. Lifetime expectancy is reduced as the strain ratio raises which is consistent with the progressive increment of fatigue striation spacing observed in the fractographic analyses.

Geometric and strain analyses in folds of the area around Gankot, district Pithoragarh, Uttarakhand, India

The study area around Gankot in Pithoragarh district of Uttarakhand belongs to the Thalkedar Limestone unit of Mandhali Formation, Tejam Group in Inner Sedimentary Zone of Lesser Himalaya, which exposes complexly folded and refolded structures. Geometric analysis carried out on the profile section of the fold tracing using dip isogon and orthogonal thickness parameters revealed presence of all the fold geometry suggested by Ramsay (1967) however the class 3 followed by class 1B are the most dominant classes in the study area when individual layers of the fold were studied. The study of folds as multilayered unit reveals that folds in study area belong to strongly non-analogous fold class of anisodeviatoric folds. In fold, the strain analysis has been done by drawing strain ellipse obtained by Inverse Thickness Method which is useful in estimating flattening strain even when the flattening is imposed obliquely to the fold’s axial trace. The finite two-dimensional flattening strain ratio (Rs) value ranged between 1 and 3.14 with an average Rs value of 1.60. The method of Srivastava and Gairola (2003) has also been used to obtain shear strain and flattening strain for the multilayered folds of study area. The results reveal that the multilayered folds around Gankot area are moderately flattened with mean flatting strain varying between 1.06 and 2.28. A very high degree of variation in shearing ranging about 70o in both clockwise and anticlockwise directions has been noticed. The shear strains (γ) in folds have been found to vary between -2.75 to + 3.27 with an average of +0.33. The shearing and strain patterns are suggestive that the most dominant folding mechanism has been the flexure-shear for the folds of the study area which are overprinted by the fold flattening and other subsequent deformations.

Strain Ratio Measurements of Patellar and Achilles Tendons With Different Reference Regions in Healthy Volunteers

Strain ratio measurements of tendons vary because of the reference tissue selection. The main purpose of this study is to highlight, in detail, the numeric variability attributable to the use of various reference materials on strain ratio measurements of patellar and Achilles tendons. Measurements were performed at the proximal, middle and distal thirds of the patellar and Achilles tendons on the dominant site of healthy volunteers. A total of 3 references were used: the Hoffa's fat pad for the patellar tendon, the Kager's fat pad for the Achilles tendon, subcutaneous tissue and Aquaflex gel pads (Parker Laboratories, Fairfield, NJ, USA) for both tendons. Although the same methods were used by the same physician for each tendon site on repeated measurements, strain ratio values had numeric variability with various reference materials in each measurement. Therefore, comparison of numeric strain ratio results of various studies with various reference materials could confuse the clinical interpretations of these numeric data, and, using a reference material with standard stiffness like Aquaflex ultrasound gel pads, should be considered by verifying these results with further studies.

Study on value of ultrasonic elastography in diagnosis of clinical staging of cervical cancer and efficacy evaluation of radiotherapy.

The aim of this study was to investigate the application of ultrasonic elastography in the diagnosis of the clinical staging of cervical cancer (CC) and its evaluation value of the treatment effect of CC. A total of 160 suspected CC patients treated in our hospital from September 2016 to March 2018 were collected. Transvaginal conventional ultrasound and ultrasonic elastography were performed on patients to compare the results of the two in the diagnosis of the pathology and clinical staging of CC. Radiotherapy was used for patients confirmed as CC75 in 160 suspected CC patients. The value difference of strain ratio (SR) between conventional ultrasound and elastic ultrasound in the efficacy evaluation of CC patients was compared. The sensitivity (94.67%), specificity (92.94%) and diagnostic accordance rate (93.75%) of ultrasonic elastography for CC were significantly higher than those of conventional ultrasound, with a statistically significant difference (P<0.001). The sensitivity and diagnostic accordance rate of ultrasonic elastography for the pathological diagnosis of CC in stage III and IV were significantly higher than those of conventional ultrasound, with a statistically significant difference (P<0.05). The sensitivity, specificity and diagnostic accordance rate of elastic ultrasound SR value in the efficacy evaluation of radiotherapy in CC patients were higher than those of conventional ultrasound. Except for the specificity, the other two P-values were <0.05, with a statistically significant difference. The elastography images of different stages of CC have some characteristic features. Ultrasonic elastography has a certain clinical value for the diagnosis and efficacy evaluation of CC.

Ultrasound elastographic assessment of the stiffness of the anteromedial knee joint capsule at varying knee angles.

In vivo evaluation of the elastic properties of the knee joint capsule has not been adequately performed. To establish a methodology to assess the stiffness of the normal knee joint capsule over a range of knee flexion angles using ultrasound elastography. Ultrasound elastography with an acoustic coupler was used to assess the stiffness of the anteromedial capsule of the knee joints of 10 male (mean age 22.63 ± 1.02 years) and 10 female (mean age 21.6 ± 0.8 years) subjects at static knee flexion angles of 0°, 45°, 90°, and 120°. Relative stiffness of the capsule was obtained using the strain ratio (SR), defined as the ratio of the strain in the capsule to that in the acoustic coupler. The intraclass correlation coefficient (1, 3) ranged from 0.95 to 0.96, and the correlation coefficient between examiners (2, 3) was 0.94. SR values decreased significantly as the flexion angle increased (P <0.01). At 90° and 120°, it was significantly higher in female than in male subjects (P <0.01). This study established a feasible and reproducible method to obtain the stiffness characteristics of the anteromedial knee joint capsule using ultrasound elastography with an acoustic coupler.