Elastography: Current Status, Future Prospects, and Making It Work for You

Real-time shear wave elastography in measuring normal ileocolon intestinal wall stiffness using colonoscopy as reference: A single-center research

Purpose

To investigate the feasibility of real-time shear wave elastography (SWE) in evaluating intestinal wall stiffness, and to establish the threshold SWE value of normal intestinal wall and explore the influencing factors of intestinal SWE.

Method

659 subjects who underwent intestinal SWE and colonoscopy were retrospectively enrolled. The wall elasticity of colonoscopy-confirmed normal/abnormal intestinal segment was measured by transabdominal SWE. Measurement reliability was evaluated by the intraclass correlation coefficient (ICC). The threshold value of SWE in differentiating normal and abnormal intestine was determined using ROC curve analysis with the largest Youden index, and the diagnostic performance of this threshold was evaluated. We explored the effects of gender, age, depth and type of the targeted intestinal segment on the intestinal wall elasticity by t test and logistic linear regression analysis.

Results

The technical success rate of SWE examination is 95.3 % (628/659). The mean SWE value of normal intestinal walls is (5.45 ± 1.34) kPa, which was significantly lower than that of abnormal ones (15.38 kPa±7.22, P < 0.001). Using 8.1 kPa as the threshold， the sensitivity and specificity were 93.5 % and 96.0 % with an AUC of 94.8 %. The overall ICC for SWE measurements was 0.933. Gender (ß=0.278, P = 0.013), depth (ß=0.220, P = 0.043) and type of the targeted segment (ß=0.522, P < 0.001) was associated with the SWE value of intestinal wall, but age was not (ß=0.050, P = 0.484).

Conclusions

SWE is feasible in evaluating the stiffness of intestinal wall with high reliability. The SWE threshold value differentiating normal intestinal wall and abnormal intestinal wall is 8.1 kPa.

Evaluation of submandibular and parotid salivary glands by ultrasonography in patients with diabetes

BACKGROUND

Microvascular complications of diabetes mellitus (DM) include oral manifestations and complications, including xerostomia, reduced salivary flow, susceptibility to infection, periodontal disease and salivary gland enlargement.

OBJECTIVE

The present study aims to evaluate B-mode ultrasonography (USG) parameters such as size, volume and echogenicity of the submandibular and parotid salivary glands on both sides, shear-wave elastography (SWE) value and colour Doppler properties in patients with DM and healthy control groups.

METHODS

In total, 160 right and left submandibular glands and 160 right and left parotid glands of 80 patients, 40 patients (20 type 1 DM, 20 type 2 DM) and 40 healthy control group, between the ages of 18-70 were examined by USG. Echogenicity, parenchyma internal structure, margin and dimensional measurements (antero-posterior length, supero-inferior length, medio-lateral length and volume) and colour Doppler with 'ML 6-15-D Matrix Array (4-15 MHz)' probe, shear-wave elastography '9L-D (2-8 MHz)' probe was investigated.

RESULT

Statistically significant difference was observed in echogenicity in the right submandibular gland, echogenicity in the right parotid gland, margin characteristics, parenchymal homogeneity and colour Doppler characteristics between the type 1 DM, type 2 DM and control groups (p < .05). It was observed that the size, volume and SWE values of both submandibular and parotid glands were higher in the DM patient group than in the control group. Higher values were observed in type 2 DM compared to type 1 DM in the patient group.

CONCLUSION

USG is an effective imaging technique in investigating the effects of diabetes on the submandibular and parotid salivary glands.

Learning-based distortion correction enables proximal-scanning endoscopic OCT elastography

Proximal rotary scanning is predominantly used in the clinical practice of endoscopic and intravascular OCT, mainly because of the much lower manufacturing cost of the probe compared to distal scanning. However, proximal scanning causes severe beam stability issues (also known as non-uniform rotational distortion, NURD), which hinders the extension of its applications to functional imaging, such as OCT elastography (OCE). In this work, we demonstrate the abilities of learning-based NURD correction methods to enable the imaging stability required for intensity-based OCE. Compared with the previous learning-based NURD correction methods that use pseudo distortion vectors for model training, we propose a method to extract real distortion vectors from a specific endoscopic OCT system, and validate its superiority in accuracy under both convolutional-neural-network- and transformer-based learning architectures. We further verify its effectiveness in elastography calculations (digital image correlation and optical flow) and the advantages of our method over other NURD correction methods. Using the air pressure of a balloon catheter as a mechanical stimulus, our proximal-scanning endoscopic OCE could effectively differentiate between areas of varying stiffness of atherosclerotic vascular phantoms. Compared with the existing endoscopic OCE methods that measure only in the radial direction, our method could achieve 2D displacement/strain distribution in both radial and circumferential directions.

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.

Ultrasonographic evaluation of the masseter muscle in patients with temporomandibular joint degeneration

Purpose

Sonographic elastography can be used to evaluate the hardness of muscle tissue through the application of compression. Strain elastography gauges hardness through the comparison of echo sets before and after compression. This study utilized ultrasonography to measure the thickness and hardness of the masseter muscle in individuals with temporomandibular joint (TMJ) osteoarthritis.

Materials and Methods

This study included 40 patients who presented with joint pain and were diagnosed with TMJ osteoarthritis via diagnostic cone-beam computed tomography, along with 40 healthy individuals. The thickness and hardness of each individual's masseter muscle were evaluated both at rest and at maximum bite using ultrasonography. The Mann-Whitney U test and the chi-square test were employed for statistical analysis, with the significance level set at P<0.05.

Results

The mean thickness of the resting masseter muscle was 0.91 cm in patients with osteoarthritis, versus 1.00 cm in healthy individuals. The mean thickness of the masseter muscle at maximum bite was 1.28 cm in osteoarthritis patients and 1.36 cm in healthy individuals. The mean masseter elasticity index ratio at maximum bite was 4.51 in patients with osteoarthritis and 3.16 in healthy controls. Significant differences were observed between patients with osteoarthritis and healthy controls in both the masseter muscle thickness and the masseter elasticity index ratio, at rest and at maximum bite (P<0.05).

Conclusion

The thickness of the masseter muscle in patients with TMJ osteoarthritis was less than that in healthy controls. Additionally, the hardness of the masseter muscle was greater in patients with TMJ osteoarthritis.

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

PURPOSE

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.

METHODS

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.

RESULTS

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).

CONCLUSION

A single dose intravitreal Ranibizumab (Lucentis®, Genentech, USA) injection does not alter the elasticity of ocular and periocular structures.

Sonographic evaluations of the skeletal muscles in patients with Pompe disease

BACKGROUND

Pompe disease usually has muscle weakness due to glycogen accumulation. Heckmatt scale is commonly used to grade the pertinent findings of ultrasound. Nonetheless, it is difficult to detect subtle changes of the muscle. Besides, no ultrasonographic parameter has been proposed to predict the motor functions of Pompe disease. Therefore, we aimed to find out an ultrasonographic parameter that can quantify the muscle involvement and correlate with the motor functions in Pompe disease.

METHODS

Eighteen patients with Pompe disease were enrolled. The echo heterogeneity index (standard deviation divided by mean echogenicity values by ImageJ analysis) and shear modulus were recorded from rectus femoris, biceps femoris, tibialis anterior, medial gastrocnemius, biceps brachii and triceps brachii muscles. Motor functions, including manual muscle strength, 6-min walk and four-limb stair climb tests were assessed. Correlations between ultrasonographic parameters and Heckmatt scale and motor functions were analyzed.

RESULTS

The echo heterogeneity index, but not the shear modulus, was negatively correlated with the Heckmatt scale rating in all muscles. The echo heterogeneity indices of tibialis anterior (r = 0.698, p = 0.008) and medial gastrocnemius (r = 0.615, p = 0.025) muscles showed positive correlations with the walking distance. Besides, the echo heterogeneity indices of four lower limb muscles were negatively correlated with the duration of stair climbing.

CONCLUSION

The echo heterogeneity index but not the shear modulus can be used to quantitatively describe the muscle involvement in Pompe disease. In addition, lower echo heterogeneity indices of lower limb muscles are associated with worse motor functions in these patients.

Aşil tendonu gerinim oranı ile mitral anulus kalsifikasyonu varlığı arasındaki ilişki

Amaç: Aşil tendonu (AT)- ultrasonografisi (US) ve gerinim elastografisi (SE) ile elde edilen AT- kalınlığı (T) ve AT- gerinim oranının (SR) mitral kapak kalsifikasyonlu (MAC) hastaları belirlemedeki önemini araştırmayı amaçladık. Gereç ve Yöntem: Çalışmaya ekokardiyografi sonrası MAC tanısı alan 100 hasta (65 kadın, 35 erkek ve ortalama yaş 64.7 ± 12.1) ve kardiyovasküler risk faktörü benzer olan 50 kontrol (32 kadın, 18 erkek ve ortalama yaş 63.2 ± 12.8) alındı. Laboratuvar incelemeler ve AT US yapıldı. AT-T ve AT-SR hesaplandı. Bulgular: MAC olan hastalarda AT-T ve AT-SR belirgin olarak yüksek olduğu bulundu. Logistic regresyon analizinde, AT-T ve AT-SR değerlerinin MAC olma riskini bağımsız olarak belirlediği bulundu. Bu analize göre AT-T (her 1 mm) ve AT-SR (her 0.1)’nin MAC olma riskini sırası ile %69.9 ve %12.7 oranlarında artırdığı saptandı. AT-T ve AT-SR değerlerinin MAC olan hastaları belirlemesi açısından ROC analizi yapıldığında, ROC eğri altında kalan alanın sırası ile 0.684 ve 0.819 belirlendi. Aynı analizde, AT-SR için sınır değer 1.25 olarak alındığında %94.1 sensitivite ve %76.2 spesivite ile MAC varlığını belirlediği tespit edildi. Sonuç: AT SE incelemesinde saptanan AT-SR, MAC olan hastaları önceden belirlemede kullanılabilecek basit, ucuz, tekrarlanabilir ve non-invaziv bir parametredir. Bu durum MAC ve AT-SR artışının benzer fizyopatolojik mekanizma ile meydana gelebilmesinin bir sonucu olabilir.

Screening for spontaneous preterm birth by cervical length and shear-wave elastography in the first trimester of pregnancy

BACKGROUND

First-trimester cervical length for the prediction of spontaneous preterm delivery remains controversial. A better method for the measurement of the first-trimester cervical length and additional cervical ultrasound parameters for the identification of women at high risk for spontaneous preterm delivery are needed.

OBJECTIVE

This study aimed to compare the predictive value of cervical length measured by 2 different methods in the first trimester of pregnancy to predict spontaneous preterm delivery and to explore the potential value of first-trimester cervical shear-wave elastography for the prediction of spontaneous preterm delivery.

STUDY DESIGN

This was a prospective study in unselected singleton pregnancies at 11⁺⁰ to 13⁺⁶ weeks' gestation. Cervical length was measured by the following 2 methods in the base-cohort population: (1) a linear distance between the 2 ends of the glandular area around the endocervical canal (single-line method: cervical length-s) and (2) a sum of the linear distance from the internal os to the greatest cervical curvature and the linear distance from this point to the external os (2-line method: cervical length-t). In a substudy, cervical shear-wave elastography scores for 9 regions of interest (inner, middle, and external parts of anterior lip, endocervical canal, and posterior lip) in midsagittal plane were also obtained by transvaginal ultrasonography. The screening performance of the first-trimester cervical length measured by the 2 different methods for the prediction of spontaneous preterm delivery was assessed by receiver operating characteristics curve analysis. The areas under the curves were compared using a DeLong test. The predictive performance of a soft cervix (mean elastography scores with multiple of median <5th, 10th, 15th, 20th, and 25th percentile) for spontaneous preterm delivery was also determined.

RESULTS

Among a total of 2316 included pregnancies, spontaneous delivery at <37 and <34 weeks' gestation occurred in 111 cases (4.8%) and 20 cases (0.9%), respectively. In the total study population, when compared with the term delivery group, the median cervical length-t was shorter in women with spontaneous delivery at <34 weeks' gestation (36.9 mm vs 35.1 mm; P=.015), but there was no clear correlation for cervical length-s. Receiver operating characteristics curves demonstrated that cervical length-t achieved better performance in predicting spontaneous delivery at <34 weeks' gestation (area under the curve, 0.658 vs 0.573; P<.01) than cervical length-s. The best combined model to predict spontaneous delivery at <34 weeks' gestation was provided by cervical length-t and history of preterm delivery (area under the curve, 0.692). In the substudy, a soft cervix with a mean elastography scores multiple of median <10th percentile had a relative risk of 7.8 (95% confidence interval, 2.1-28.6) for spontaneous delivery at <34 weeks' gestation; the detection rate was 44.4% at a false-positive rate of 9.0%.

CONCLUSION

The 2-line approach provides a better estimate of the actual first-trimester cervical length and achieves better performance as a screening tool for spontaneous preterm delivery at <34 weeks' gestation than the conventional measurement. A soft cervix as determined by shear-wave elastograpthy in the first trimester is associated with an increased risk for subsequent spontaneous preterm delivery.

The Value of Ultrasound Elastography in Diffuse Thyroid Disease among a Sample of Iraqi Population

Abstract Background: Early detection of many thyroid disorders is essential in the management. Ultrasound elastography is beneficial in the assessment of diffuse thyroid diseases.      Aim of study: To assess the role of ultrasound strain elastography in the diagnosis of diffuse non nodular thyroid disease in comparison to healthy controls and in the characterization and differentiation of the types of diffuse thyroid diseases. Patients and methods: It is a prospective analytic study performed in the Radiology Department of Oncology Teaching Hospital/Medical city Complex in Baghdad during the period from 1st of December 2019 to 30th of June, 2020 on convenient sample of 25 patients with diffuse thyroid disease, in addition to a sample of 25 healthy control persons. The diagnosis of diffuse thyroid diseases was made by combination of clinical symptoms, laboratory investigations and thyroid ultrasound. Results: The mean elastography strain ratio (1.36) of patients with diffuse thyroid disease was significantly higher than (0.82) mean of elastography strain ratio for healthy control persons (p<0.001). The acceptable cutoff elastography strain ratio in the diagnosis of diffuse thyroid disease was 0.89 with validity results (80% sensitivity, 70% specificity and 75% accuracy). The mean elastography strain ratio for patients with Hashimotos thyroiditis was significantly higher than the strain ratio of patients with Graves disease (p=0.002). Conclusions: The ultrasound elastography is useful in the assessment and characterization of diffuse thyroid disease. The ultrasound elastography strain ratio value is helpful in differentiation between different diffuse thyroid diseases especially between Hashimotos thyroiditis and Graves's disease

Quantifying Lower Limb Muscle Stiffness as Ambulation Function Declines in Duchenne Muscular Dystrophy with Acoustic Radiation Force Impulse Shear Wave Elastography

Duchenne muscular dystrophy (DMD) is a progressive muscular disease, but validated imaging tools to quantify muscle microstructure alteration as mobility declines are lacking. We aimed to determine the feasibility of using acoustic radiation force impulse shear-wave elastography (ARFI/SWE) in the quantitative assessment of lower limb muscle stiffness in DMD patients. Shear wave velocities (SWVs) of lower limbs were measured in 39 DMD patients and 36 healthy controls aged 3-20 y. Mean SWV values of the controls and of the DMD patients at different ambulatory stages were compared using analysis of variance with Bonferroni correction. The DMD group had increased lower limb muscle stiffness compared with controls. Stiffness of the tibialis anterior and medial gastrocnemius muscle decreased from ambulatory to early non-ambulatory stages, whereas stiffness of the rectus femoris muscle increased from ambulatory to late non-ambulatory stages. We describe how SWV changes in lower limb muscles have the potential to predict ambulatory decline in DMD.

Shear-wave elastography in thyroid ultrasound: Can be a predictor of extrathyroidal extension and cervical lymph node metastasis in papillary thyroid carcinoma?

ABSTRACT

This study aimed to investigate whether extrathyroidal extension (ETE) and cervical lymph node metastasis (LNM) can be predicted using elasticity parameters of shear-wave elastography (SWE) combined with B-mode ultrasound (US) of papillary thyroid carcinomas (PTCs).We retrospectively reviewed 111 patients who underwent preoperative SWE evaluation among PTC patients from July 1, 2016 to June 20, 2018. Patients were divided into 2 groups based on the presence or absence of ETE based on pathology reports. Univariate and multivariate analyses of clinical and radiologic features including B-mode US features, US patterns, and SWE parameters were performed. These analyses were repeated in LNM positive and negative groups. The diagnostic performance of SWE parameters were also evaluated.Of the 111 patients, 33 had ETE, 78 did not have ETE, 44 had LNM, and 67 did not have LNM. A taller-than-wide shape and T3 stage on US were associated with ETE. Female sex, total thyroidectomy, and T3 stage on US were associated with LNM. When B-mode US and SWE were combined, there was no improvement in diagnostic performance.Combination of SWE and B-mode US findings is not useful for predicting ETE and LNM status in PTC patients.

A Comparison Study of Conventional Ultrasound and Ultrasound Strain Elastography in the Evaluation of Myopathy

The aim of this study was to compare ultrasound strain elastography (USE) with conventional ultrasonography echogenicity (EL) in detecting muscle pathology. For conventional ultrasonography, biceps EL was obtained. For USE, elasticity index (EI) of biceps was represented as a range, from 0 (softest) to 6 (hardest). Muscle-to-fats elasticity ratio compared EI of muscle with that of surrounding fats. Color distribution of elastogram was analyzed using open-source ImageJ software showing % red, % green, and % blue within a region of interest. Increased biceps EL, decreased biceps EI, and elasticity ratio were observed in patients with myopathy. In the color elastogram, there is no significant difference in % green between healthy control and patient, but significance was observed in % red and % blue (P < 0.001). Utilization of USE parameters has increased sensitivity up to 100% compared with 63% with conventional US. It is a promising adjunct for the clinical diagnosis of myopathy.

Use of Shear Wave Elastography for Quantitative Assessment of Muscle Stiffness After Botulinum Toxin Injection in Children With Cerebral Palsy

OBJECTIVES

This study aimed to investigate the stiffness of the gastrocnemius (GC) muscle with acoustic radiation force impulse (ARFI) elastography after botulinum toxin-A (BTX-A) injection in children with spastic cerebral palsy (CP) and to examine the relationship between elastographic and clinical parameters.

METHODS

This prospective randomized single-blind controlled clinical study included 49 lower extremities of 33 children with spastic CP. They were randomized into 2 groups: group 1 (n = 25 extremities in 17 children) received BTX-A injection and a home-based exercise program; group 2 (n = 24 extremities in 16 children) received only a home-based exercise program. Patients were evaluated in pretreatment and posttreatment periods in the first and third months with ARFI elastography, the Modified Ashworth Scale, Modified Tardieu Scale, Pediatric Functional Independence Measure, Gross Motor Function Classification System, and goniometric range of motion measurement of the ankle.

RESULTS

A statistically significant difference was found in elastography of the GC muscle in group 1 only at the first month after treatment (P < .05). No statistical difference was found in elastography of the GC after treatment in group 2. According to the Modified Ashworth Scale, Modified Tardieu Scale, and ankle passive range of motion, group 1 showed significant improvements after treatment (P < .05). Also, there was a significant correlation between these clinical parameters and elastographic measurements (P < .05).

CONCLUSIONS

According to the results of this study, the measurements from ARFI elastography combined with clinical parameters might be useful for evaluation of spasticity after BTX-A treatment in children with CP. Also, they might be useful in distinguishing patients who will benefit clinically, especially in the early stages of treatment.

Diagnostic reliability of elastography in thyroid nodules reported as indeterminate at prior fine-needle aspiration cytology (FNAC): a systematic review and Bayesian meta-analysis

OBJECTIVES

To assess the diagnostic yields of elastography in thyroid nodules reported as indeterminate in FNAC according to guidelines.

METHODS

Databases of Medline, Embase, and Cochrane Central were searched till 31 October 2019. Two different reviewers check the studies and extracted the data. The diagnostic accuracy and yield were quantitatively synthesized using Bayesian bivariate model in R.

RESULTS

Twenty studies with 1734 indeterminate thyroid nodules undergoing elastography were included. The summary estimates of sensitivity and specificity were 0.766 (95% credible interval (CrI), 0.686-0.835) and 0.867 (95% CrI, 0.780-0.931), respectively. The summary estimate for diagnostic odds ratio (DOR) was 25.9 (95% CrI, 12.8-46.2). Summary receiver operating characteristic plots for elastography showed a right-diagonal curvilinear relationship, suggesting a trade-off between sensitivity and specificity, and the estimate of area under curve (AUC) was 0.743. The summary estimates for positive and negative likelihood ratios were 6.6 (95% CrI, 4.2-11.3) and 0.27 (95% CrI, 0.21-0.36), respectively.

CONCLUSIONS

Elastography had fair diagnostic yields in indeterminate thyroid nodules. Shear wave elastography and strain ratio elastography could be more efficient in diagnosis and should evolve in the next years while combing elastography with ultrasound would contribute more to sensitivity and specificity currently.

KEY POINTS

• Elastography has fair diagnostic yields in indeterminate thyroid nodules. • Shear wave elastography and strain ratio elastography are more efficient than real-time elastography. • Combining elastography and other ultrasound techniques improves evaluation of indeterminate thyroid nodules.

Association between elastography findings of the levator ani and stress urinary incontinence

PURPOSE

To investigate the elasticity of the levator ani musle (LAM) with the patients suffering from stress urinary incontinence (SUI) by transperineal elastography.

METHODS

Conventional transperineal ultrasound and elastography were performed in the patients with SUI on quiescent condition and maximal Valsalva. Transperineal ultrasound and elastography were repeated after Kegel exercises. The scoring system and strain ratio (SR) values were recorded and analyzed.

RESULTS

After Kegel exercises, the ratio of subjective improvement or cure was 81 % (102/126). Mean elasticity score (ES) and SR of LAM were significantly higher than the value before on maximal Valsalva, respectively. Mean ES and SR of LAM after Kegel exercises were similar with the value before on quiescent condition, respectively.

CONCLUSION

The improvement of SUI was associated with the stiffer LAM assessed by elastography. Women with SUI who have softer LAM were more likely to have symptoms of SUI and Kegel exercise could strengthen the stiffness of LAM.

BRIEF SUMMARY

The improvement of SUI was associated with the stiffer LAM assessed by elastography.

Diagnostic Performance of Acoustic Radiation Force Impulse Elastography for the Differentiation of Benign and Malignant Superficial Lymph Nodes: A Meta-analysis

To estimate the diagnostic performance of acoustic radiation force impulse elastography in distinguishing between benign and malignant superficial lymph nodes, relevant articles published before October 31, 2018, in China and other countries were used. Conclusively, a total of 18 articles were analyzed. Sixteen studies used Virtual Touch tissue quantification (Siemens Healthineers, Erlangen, Germany), and 4 studies used Virtual Touch tissue imaging (Siemens Healthineers). After a meta-analysis, it was found that acoustic radiation force impulse elastography is an efficient method for detecting superficial lymph nodes. In addition, if the cutoff value for the shear wave velocity were less than 2.85 m/s, the summary sensitivity would increase, and the heterogeneity would be reduced.

Postoperative diagnostic potentials of median nerve strain and applied pressure measurement after carpal tunnel release

Bakground

The objective of this study is to investigate the prognostic values of median nerve strain and applied pressure measurement for the assessment of clinical recovery after carpal tunnel release.

Methods

Forty-five wrists, from 45 idiopathic carpal tunnel syndrome patients who treated with open carpal tunnel release, were evaluated by ultrasound. Median nerve strain, pressure applied to the skin, and ratio of pressure-strain were measured at the proximal part of the carpal tunnel. In addition, distal latencies in the motor and sensory nerve conductions studies and cross-sectional area of median nerve were measured. The parameters were compared before and after the open carpal tunnel release. According to patient recovery, the receiver operating characteristic curves were generated to evaluate the prognostic values of the parameters. The areas under the receiver operating characteristic curves were compared among parameters.

Results

There was a significant increase in the median nerve strain, and significant decreases in the pressure applied to the skin and ratio of pressure-strain after carpal tunnel release (P < 0.01). There were significant decreases in the distal latencies and the cross-sectional area after carpal tunnel release (P < 0.01). The areas under the curves were 0.689, 0.773, 0.811, 0.668, 0.637, and 0.562 for the pressure, strain, pressure-strain ratio, motor latency, sensory latency, and area, respectively.

Conclusions

The results suggest that elasticity of the median nerve and pressure around the nerve recover quickly after carpal tunnel release. Pressure-strain ratio was the most reliable parameter to reflect clinical recovery. The measurement of strain and applied pressure can be useful indicators to evaluate effectiveness of the carpal tunnel release.

Trial registration

Registered as NCT04027998 at ClinicalTrials.gov. Retrospectively registered on July 22, 2019.

Clinical Efficacy of Real-Time Sonoelastography for the Follow-Up of Congenital Sternocleidomastoid Muscle Torticollis

Purpose

To evaluate the clinical efficacy of real-time sonoelastography (RTS) for the follow-up of congenital muscular torticollis, based on measurements of muscle elasticity.

Materials and Methods

Thirty-four infants (23 male, 11 female) with congenital sternocleidomastoid (SCM) muscle torticollis underwent ultrasonography and elastography between November 2012 and December 2014. We evaluated the thickness, morphology (mass-like, fusiform, or overall thickened shape), and echogenicity of the SCM muscle on grayscale images and color patterns (homogeneous blue, mixed green < 50% and ≥ 50%, and green to red) on elastography. Strain ratios were measured using Q-lab software. A clinician classified the degree of neck rotation and side flexion deficits using a 5-point grade system based on angles of neck rotation and side flexion. Correlations between the ultrasonography and clinical findings were evaluated by statistical analysis.

Results

Twenty-two infants had right and 12 had left SCM torticollis, respectively. Linear regression analysis showed that involved/contralateral SCM thickness differences, morphology, elasticity color scores, and strain ratios of the affected SCM muscles were significantly correlated with neck rotation and side flexion deficit scores (p < 0.05). The elasticity color score of the affected SCM muscle was the most significant factor.

Conclusion

RTS might provide a reliable means for evaluating and monitoring congenital muscular torticollis.

Association Between the Elasticity of Hip Muscles and the Hip Migration Index in Cerebral Palsy

OBJECTIVES

Cerebral palsy (CP) increases the risk of hip displacement during childhood. Abnormal hip muscle forces have been proposed as the predisposing factors. In CP, the amount of hip displacement is commonly evaluated by the Reimers hip migration index (MI) on an anteroposterior pelvic radiograph. To the best of our knowledge, the association between the elasticity of hip muscles measured by shear wave elastography and the MI has not been studied yet. Herein, we aimed to analyze the correlation between the elasticity of hip muscles and the MI.

METHODS

Bilateral hips of 25 children with spastic CP were included prospectively in this study. Anteroposterior pelvic radiographs were used to measure the MI. Shear wave elastography was performed to evaluate the elasticity of muscles. The correlation between the MI and the elasticity of hip flexor and adductor muscle groups was assessed. Also, the association between the elasticity of agonist/antagonist muscles was analyzed.

RESULTS

The MI showed fair to good correlations with hip flexors and adductors for both readers (0.71 ≥ r ≥ 0.52). The mean MIs of the patients ± SDs were 22.64% ± 7.79% for reader 1 and 21.55% ± 8.83% for reader 2. The elasticity of agonist/antagonist muscle groups showed little/no to a weak correlation for both readers (0.32 ≥ r ≥ -0.07).

CONCLUSIONS

Although, hip flexor and adductor muscle elasticity showed a correlation with MI, it seems very hard to say that increased elasticity of hip flexor and adductor muscles causes hip dislocation.

Incorporation of shear wave elastography into a prediction model in the assessment of cervical lymph nodes

Rationale and objectives

To assess the performance of shear wave elastography (SWE) and an extended model in predicting malignant cervical lymph nodes (LNs).

Materials and methods

109 patients who underwent ultrasound (US) and SWE before needle biopsy were enrolled. The optimal cutoff value of elasticity indices (EIs) was determined by receiver operating characteristic (ROC) curves. The c-statistic, net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were used to compare extended model and traditional one.

Results

Malignant LNs had higher EIs than benign nodes (p < 0.001). The optimal cutoff point was 42 kilopascal, corresponding to 83.3% sensitivity, 64.7% specificity, and 68.8% overall accuracy. A multivariable logistic regression analysis confirmed that EI was an independent predictor for malignancy. The new extended prediction model had a positive NRI (0.96) and IDI (0.10) for predicting malignant neck LNs. Nevertheless, the c-statistic was not significantly different between the two models.

Conclusion

The parameter of SWE theoretically improve the model performance. However, its real clinical impact is minor, as the parameters of US-based model is already very robust. SWE can be considered as an adjunctive quantitative tool beyond conventional US examination.

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.

Real-time ultrasound elastographic evaluation of extraocular muscle involvement in Graves' ophthalmopathy

Purpose: To evaluate the affected extraocular muscles (EOMs) of patients with Graves' ophthalmopathy (GO) using real-time ultrasound elastography (UE) and to compare these results with those of healthy subjects.Methods: This prospective, comparative case series included 70 eyes of 35 patients with moderate-to-severe GO with type 2 orbitopathy (myogenic variant) according to their computed tomography (CT) scans. Forty-six eyes of 23 healthy subjects were evaluated as the control group. The strain ratio of orbital fat to medial rectus was calculated as the ratio of the medial rectus to orbital fat tissue, and the strain ratio of orbital fat to lateral rectus was calculated as the ratio of lateral rectus to orbital fat tissue.Results: The strain ratio of orbital fat to medial rectus was 3.03 ± 1.25 (range: 1.05-5.07) in the GO group, and 0.54 ± 0.20 (range: 0.14-1.08) in the control group (p = .0001). The strain ratio of orbital fat to lateral rectus was 0.97 ± 0.29 (range: 0.56-1.55) in the GO group, and 0.63 ± 0.23 (range: 0.18-1.09) in the control group (p = .0001).Conclusion: By using real-time UE, we found the medial and the lateral recti of GO patients to be stiffer compared to those of healthy subjects.

Usability of Achilles tendon strain elastography for the diagnosis of coronary artery disease

PURPOSE

There are close relationships between major coronary artery disease (CAD) risk factors and Achilles tendon thickness (AT-T) and AT strain ratio (AT-SR). Our aim was to evaluate the diagnostic importance of AT-T and AT-SR as obtained by ultrasonography (USG) and strain elastography (SE) for predicting CAD.

MATERIALS AND METHODS

One hundred and eighty-four patients scheduled to undergo coronary angiography were included in the study. Achilles tendon USG (B-mode and SE) and laboratory tests were performed on all patients. The patients were divided into two groups, i.e., patients with and without CAD.

RESULTS

The patients with CAD (72.8%) were more likely to be male, exhibited higher frequencies of diabetes mellitus (DM) and hyperlipidemia, exhibited higher levels of basal creatinine and glucose, and had higher AT-T and AT-SR values (p < 0.05 for all). Age, DM, AT-T, and AT-SR independently predicted the probability of CAD in a logistic regression analysis (p < 0.05 for all). Age (each year), DM (presence), AT-T (each 1 mm), and AT-SR (each 0.1) increased the CAD risk by 3.4%, 2.9 times, 47.1%, and 16.0%, respectively. ROC analysis revealed AUCs of 0.665 and 0.730 for the AT-T and AT-SR values, respectively (p < 0.05). The AT-SR cutoff value of 1.2 predicted the presence of CAD with 75.4% sensitivity and 72.7% specificity.

CONCLUSIONS

AT-SR is a simple, inexpensive, noninvasive, reproducible, and objective parameter for the prediction of CAD. We think that AT-SR evaluation should become a part of conventional USG assessments in patients who are at a high risk of CAD.

Imaging in the diagnosis of idiopathic inflammatory myopathies; indications and utility

INTRODUCTION

Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of muscle diseases that carry a significant morbidity and mortality risk. The utilization of imaging in the diagnostic pathway of IIM is therefore important to obtain early diagnosis and even monitor patients over time. Areas covered: Magnetic resonance imaging (MRI) has been the main imaging modality used to detect myositis but limitations include cost and accessibility, leading to delays in time to scan, and patient contraindications. This has led to the exploration of other imaging techniques to diagnose and monitor response to therapy. This article is based primarily on a literature search via PubMed using Boolean terms 'myositis' and the various imaging modalities. Expert opinion: Imaging is sensitive to pathology in IIM and may contribute to the diagnostic process. Learning how specific imaging features can distinguish different forms of IIM may allow more rapid diagnosis of myositis subtype and treatment planning, and to monitor disease activity particularly in patients who respond poorly to treatment. However, more work is needed to investigate the validity and relative utility of these imaging modalities.

Accuracy and Reproducibility of Sonoelastography for the Assessment of Fibroids and Adenomyosis, with Magnetic Resonance Imaging as Reference Standard

The aims of this prospective diagnostic evaluation study were (i) to estimate the inter-observer agreement and reproducibility of real-time sonoelastography and real-time gray-scale ultrasound in the measurement of uterine and fibroid volumes; (ii) to evaluate the agreement between real-time gray-scale ultrasound, sonoelastography and magnetic resonance imaging with respect to these outcomes; and (iii) to evaluate the diagnostic accuracy of sonoelastography in the diagnosis of uterine pathology on stored sonoelastography and gray-scale cine loops. Women without a history of uterine pathology and with the diagnosis intrauterine fibroids or adenomyosis were included. All participants underwent gray-scale ultrasound, sonoelastography and magnetic resonance imaging. Compression sonoelastography was found to have high inter-observer and inter-method agreement for the measurement of uterine and fibroid volumes. The addition of sonoelastography to gray-scale ultrasound seems to be useful in the differentiation between fibroids, adenomyosis and normal uteri as reflected by an increase in accuracy and diagnostic agreement.

A soft cervix, categorized by shear-wave elastography, in women with short or with normal cervical length at 18-24 weeks is associated with a higher prevalence of spontaneous preterm delivery

OBJECTIVE

To determine whether a soft cervix identified by shear-wave elastography between 18 and 24 weeks of gestation is associated with increased frequency of spontaneous preterm delivery (sPTD).

MATERIALS AND METHODS

This prospective cohort study included 628 consecutive women with a singleton pregnancy. Cervical length (mm) and softness [shear-wave speed: (SWS) meters per second (m/s)] of the internal cervical os were measured at 18-24 weeks of gestation. Frequency of sPTD <37 (sPTD<37) and <34 (sPTD<34) weeks of gestation was compared among women with and without a short (≤25 mm) and/or a soft cervix (SWS <25th percentile).

RESULTS

There were 31/628 (4.9%) sPTD<37 and 12/628 (1.9%) sPTD<34 deliveries. The combination of a soft and a short cervix increased the risk of sPTD<37 by 18-fold [relative risk (RR) 18.0 (95% confidence interval [CI], 7.7-43.9); P<0.0001] and the risk of sPTD<34 by 120-fold [RR 120.0 (95% CI 12.3-1009.9); P<0.0001] compared to women with normal cervical length. A soft-only cervix increased the risk of sPTD<37 by 4.5-fold [RR 4.5 (95% CI 2.1-9.8); P=0.0002] and of sPTD<34 by 21-fold [RR 21.0 (95% CI 2.6-169.3); P=0.0003] compared to a non-soft cervix.

CONCLUSIONS

A soft cervix at 18-24 weeks of gestation increases the risk of sPTD <37 and <34 weeks of gestation independently of cervical length.

Factors Affecting the Quality of Breast Quasistatic Ultrasound Elastograms

OBJECTIVES

To explore factors affecting the quality of quasistatic ultrasound elastograms of the breast and to evaluate their accuracy in distinguishing benign and malignant breast lesions.

METHODS

A total of 663 patients with 702 breast lesions were recruited. All patients received both conventional ultrasonography and quasistatic elastography. Patients' breast lesions were divided into A and B groups according to satisfactory and unsatisfactory elastographic examinations. Group A included 590 satisfactory elastograms, whereas Group B included 112 unsatisfactory elastograms. Various factors-maximum depth of the lesion, maximum transverse diameter of the lesion, thickness of the adipose layer, thickness of the glandular layer, thickness of the breast, distance between the nipple and lesion, age, body mass index, and menopausal status-were analyzed and compared between the groups to gauge their effects on the quality of the elastograms.

RESULTS

Significantly deeper lesions, higher maximum transverse lesion diameters, thicker adipose layers, thicker glandular layers, and thicker breasts were identified in group B patients compared to group A patients (P < .05). Multivariate logistic regression analyses showed that the maximum depth of the lesion, thickness of the adipose layer, and thickness of the breast were independent factors in the quality of elastograms. The area under the curve for the maximum depth of the lesion was 0.986 with the optimal cutoff threshold of 2.5 cm.

CONCLUSIONS

Quasistatic elastography can be a supplementary approach to conventional ultrasonography in helping improve the diagnostic accuracy of breast lesions. The depth and size of breast lesions are correlated with the quality of elastograms.

Ex Vivo Shear-Wave Elastography of Axillary Lymph Nodes to Predict Nodal Metastasis in Patients with Primary Breast Cancer

Purpose

There is still a clinical need to easily evaluate the metastatic status of lymph nodes during breast cancer surgery. We hypothesized that ex vivo shear-wave elastography (SWE) would predict precisely the presence of metastasis in the excised lymph nodes.

Methods

A total of 63 patients who underwent breast cancer surgery were prospectively enrolled in this study from May 2014 to April 2015. The excised axillary lymph nodes were examined using ex vivo SWE. Metastatic status was confirmed based on the final histopathological diagnosis of the permanent section. Lymph node characteristics and elasticity values measured by ex vivo SWE were assessed for possible association with nodal metastasis.

Results

A total of 274 lymph nodes, harvested from 63 patients, were examined using ex vivo SWE. The data obtained from 228 of these nodes from 55 patients were included in the analysis. Results showed that 187 lymph nodes (82.0%) were nonmetastatic and 41 lymph nodes (18.0%) were metastatic. There was significant difference between metastatic and nonmetastatic nodes with respect to the mean (45.4 kPa and 17.7 kPa, p<0.001) and maximum (55.3 kPa and 23.2 kPa, p<0.001) stiffness. The elasticity ratio was higher in the metastatic nodes (4.36 and 1.57, p<0.001). Metastatic nodes were significantly larger than nonmetastatic nodes (mean size, 10.5 mm and 7.5 mm, p<0.001). The size of metastatic nodes and nodal stiffness were correlated (correlation coefficient of mean stiffness, r=0.553). The area under curve of mean stiffness, maximum stiffness, and elasticity ratio were 0.794, 0.802, and 0.831, respectively.

Conclusion

Ex vivo SWE may be a feasible method to predict axillary lymph node metastasis intraoperatively in patients undergoing breast cancer surgery.

Power Doppler Ultrasonography and Shear Wave Elastography as Complementary Imaging Methods for Suspected Local Breast Cancer Recurrence

OBJECTIVES

To prospectively investigate the diagnostic accuracy and clinical consequences of power Doppler morphologic criteria and shear wave elastography (SWE) as complementary imaging methods for evaluation of suspected local breast cancer recurrence in the ipsilateral breast or chest wall.

METHODS

Thirty-two breast masses with a suspicion of local breast cancer recurrence on B-mode ultrasonography underwent complementary power Doppler and SWE evaluations. Power Doppler morphologic criteria were classified as avascular, hypovascular, or hypervascular. Shear wave elastography was classified according to a 5-point scale (SWE score) and SWE maximum elasticity. Diagnostic accuracy was assessed by the sensitivity, specificity, and area under the curve. A decision curve analysis assessed clinical consequences of each method. The reference standard for diagnosis was defined as core needle or excisional biopsy.

RESULTS

Histopathologic examinations revealed 9 (28.2%) benign and 23 (71.8%) malignant cases. Power Doppler ultrasonography (US) had sensitivity of 34.8% (95% confidence interval [CI], 6.6%-62.9%) and specificity of 45.4% (95% CI, 19.3%-71.5%). The SWE score (≥3) had sensitivity of 87.0% (95% CI, 66.4%-97.2%) and specificity of 44.4% (95% CI, 13.7%-78.8%). The SWE maximum elasticity (velocity > 6.5cm/s) had sensitivity of 87% (95% CI, 66.4%-97.2%) and specificity of 77.8% (95% CI, 40.0% to 97.2%). The areas under the curves for the SWE score and SWE maximum elasticity were 0.71 (95% CI, 0.53-0.87) and 0.82 (95% CI, 0.64-0.93), respectively (P = .32).

CONCLUSIONS

Power Doppler US is unsuitable for discrimination between local breast cancer recurrence and fibrosis. Although the SWE score and SWE maximum elasticity can make this discrimination, the use of these methods to determine biopsy may lead to poorer clinical outcomes than the current practice of performing biopsies of all suspicious masses.

Qualitative and Semiquantitative Elastography for the Diagnosis of Intermediate Suspicious Thyroid Nodules Based on the 2015 American Thyroid Association Guidelines

OBJECTIVES

To evaluate qualitative and semiquantitative elastography for the diagnosis of intermediate suspicious thyroid nodules based on the 2015 American Thyroid Association (ATA) guidelines.

METHODS

Through a retrospective search of our institutional database, 746 solid thyroid nodules found on grayscale ultrasonography, strain elastography, and ultrasound-guided fine-needle aspiration between June and November 2009 were collected. Among them, 80 nodules from 80 patients with an intermediate suspicion of malignancy based on the 2015 ATA guidelines that were 10 mm or larger were recruited as the final study nodules. Elastographic findings were categorized according to the criteria of Rago et al (J Clin Endocrinol Metab 2007; 92:2917-2922) and Asteria et al (Thyroid 2008; 18:523-531), and strain ratio values were calculated and recorded. The independent 2-sample t test and χ² test (or Fisher exact test) were used to evaluate differences in clinical parameters between benign and malignant thyroid nodules. All variables were compared by univariate and multivariate logistic regression analyses, and odds ratios with 95% confidence intervals were calculated.

RESULTS

Of the 80 nodules, 6 (7.5%) were malignant, and 74 (92.5%) were benign. No significant differences were observed in age, sex, nodule size, elasticity score, and strain ratio between benign and malignant nodules. No variables significantly predicted thyroid malignancy on the univariate analysis. On the multivariate logistic regression analysis, there were no independent variables associated with thyroid malignancy, including the elasticity score and strain ratio (all P > .05).

CONCLUSIONS

Elastographic analysis using the elasticity score and strain ratio has limited ability to characterize the benignity or malignancy of thyroid nodules with an intermediate suspicion of malignancy based on the 2015 ATA guidelines.

Shear wave elastography and Afirma™ gene expression classifier in thyroid nodules with indeterminate cytology: a comparison study

PURPOSE

To compare shear wave elastography (SWE) and Afirma™ gene expression classifier (GEC) for diagnosis of malignancy in thyroid nodules (TNs) with Bethesda Classification (BC) III or IV indeterminate cytology.

METHODS

This preliminary single-center prospective study was approved by the Institutional Review Board. We evaluated 151 consented patients with 151 indeterminate TNs (123 BC III, 28 BC IV) on fine-needle aspiration biopsy (FNAB). B-mode ultrasound, vascularity, and SWE were performed prior to FNAB. TN stiffness was measured as shear wave velocity (SWV) in meters per second (m/s). The stiffest area of the TN was selected for SWV measurement. GEC testing was performed with a second FNAB. Surgery was recommended for GEC-suspicious TNs, or GEC-benign TNs with two or more worrisome B-mode US features.

RESULTS

Surgical pathology confirmed 31 malignant TNs. Among the GEC-suspicious group, 28 of 59 TNs were malignant. The SWV value of ≥3.59 m/s was the best cut-off for malignancy risk based on the receiver operating curve (ROC). Twenty-six malignant TNs had SWV ≥ 3.59 m/s. The sensitivity and specificity for SWV ≥ 3.59 m/s were 83.9 and 79.2%, respectively. Positive predictive value (PPV) was 51.0% and negative predictive value (NPV) was 95.0%. For the GEC-suspicious group, sensitivity, specificity, PPV, and NPV were 90.3, 74.2, 47.5, and 96.7%, respectively. In multivariate analysis, SWV and GEC-suspicious were significant predictors of malignancy, but B-mode features and vascularity were not.

CONCLUSION

This preliminary study indicates that SWE and GEC are independent predictors of malignancy in TNs with BC III or IV.

Non-invasive assessment of kidney allograft fibrosis with shear wave elastography: A radiological-pathological correlation analysis

OBJECTIVES

To evaluate the use of shear wave elastography in assessment of kidney allograft tubulointerstitial fibrosis.

METHODS

Shear wave elastography assessment was carried out by two independent operators in kidney transplant recipients who underwent allograft biopsy for clinical indications (i.e. rising creatinine >15% or proteinuria >1 g/day). Allograft biopsies were interpreted by the same pathologist according to the 2013 Banff Classification.

RESULTS

A total of 40 elastography scans were carried out (median creatinine 172.5 μmol/L [interquartile range 133.8-281.8 μmol/L]). Median tissue stiffness at the cortex (22.6 kPa [interquartile range 18.8-25.7 kPa] vs 22.3 kPa [interquartile range 19.0-26.5 kPa], P = 0.70) and medulla (15.0 kPa [interquartile range 13.7-18.0 kPa] vs 15.6 kPa [interquartile range 14.4-18.2 kPa]) showed no significant differences between the two observers. Interobserver agreement was satisfactory (intraclass correlation coefficient of the cortex 0.84, 95% CI 0.70-0.92 and intraclass correlation coefficient of the medulla 0.88, 95% CI 0.78-0.94). The areas under the receiver operating characteristic curves for detection of tubulointerstitial fibrosis were estimated to be 0.75 (95% CI 0.61-0.89), 0.85 (95% CI 0.75-0.95) and 0.65 (95% CI 0.53-0.78) for cortical, medullary tissue stiffness and serum creatinine, respectively.

CONCLUSIONS

Shear wave elastography can be used as a non-invasive tool to evaluate kidney allograft fibrosis with reasonable interobserver agreement and superior test performance to serum creatinine in detecting early tubulointerstitial fibrosis.

Quantitative Evaluation of Denervated Muscle Atrophy with Shear Wave Ultrasound Elastography and a Comparison with the Histopathologic Parameters in an Animal Model

This study explored the efficacy of shear wave ultrasound elastography (SWUE) for quantitative evaluation of denervated muscle atrophy in a rabbit model. The elastic modulus of the triceps surae muscle was measured with SWUE and compared with histopathologic parameters at baseline and at various post-denervation times (2, 4 and 8 wk) with 10 animals in each group. Our results revealed that the elastic modulus of denervated muscle was significantly lower at 2 wk but higher at 8 wk compared with that at the baseline (p <0.05), and no significant difference was found between the elastic modulus at 4 wk and that at the baseline (p > 0.05). The wet-weight ratio and the muscle fiber cross-sectional area of the denervated muscle decreased gradually during the 8 wk post-denervation together with a gradual increase of the collagen fiber area (p <0.05). In conclusion, SWUE was useful for quantitative evaluation of muscle denervation. The decreased elastic modulus might be an early sign of denervated muscle atrophy.

Measurements of the trapezius and erector spinae muscles using virtual touch imaging quantification ultrasound-Elastography: a cross section study

Background

This study uses virtual touch imaging quantification (VTIQ) technology for the first time to conduct measurements of the trapezius and erector spinae muscles in a large study population. The significance of various influencing factors, such as age and sex, are also examined.

Method

The study population comprised 278 subjects. The Siemens Acuson S3000 and VTIQ technology were used for measurements of the trapezius and erector spinae muscles (Siemens Healthcare, Erlangen, Germany).

Results

The following mean values ± standard deviation were calculated: left trapezius: males 2.89 ± 0.38 m/s, females 2.71 ± 0.37 m/s; right trapezius: males 2.84 ± 0.41 m/s, females 2.70 ± 0.38 m/s; left erector spinae: males 2.97 ± 0.50 m/s, females 2.81 ± 0.57 m/s; right erector spinae: males 3.00 ± 0.52 m/s, females 2.77 ± 0.59 m/s. A significant difference between male and female subjects was demonstrated both for the shear wave velocities of the trapezius and erector spinae as well as for the thickness of the trapezius muscle (p < 0.05). There was also a significant difference in muscle elasticity between subjects over 60 years of age and those under 60 (p < 0.05). Furthermore, the results indicate that regular physical activity has an effect on muscle elasticity.

Conclusions

Our results demonstrate significantly different results between male and female subjects and between under- and over-sixty-year-old subjects. This means that sex-related and age-adapted considerations are obviously needed for further studies.

Measurement of Median Nerve Strain and Applied Pressure for the Diagnosis of Carpal Tunnel Syndrome

The objective of this study was to evaluate the diagnostic utility of strain and applied-pressure measurements of the median nerve in carpal tunnel syndrome (CTS). Thirty-five wrists of 23 idiopathic CTS patients and 30 wrists of 15 normal patients were examined. Median nerve strain, pressure to the skin and the pressure/strain ratio were measured at the proximal carpal tunnel level. Parameters were compared between CTS patients and controls. The areas under the receiver operating characteristic curves (AUCs) were compared for the parameters. Median nerve strain was significantly lower in the patients than in the controls (p < 0.01). Pressure and pressure/strain ratio were significantly higher in the patients than in the controls (p < 0.05: pressure, p < 0.01: ratio). The AUCs were 0.926, 0.681 and 0.937 for strain, pressure and pressure/strain ratio, respectively. Pressure/strain ratio is useful for evaluating the condition of the median nerve with respect to the hardness of the surrounding structures in CTS.

Elastographic Findings of Achilles Tendons in Asymptomatic Professional Male Volleyball Players

OBJECTIVES

Elastography is a new sonographic technique that evaluates the elasticity of different tissues such as the Achilles tendon. In this study, we aimed to investigate the elastographic findings of Achilles tendons in professional athletes in comparison with healthy volunteers.

METHODS

Twenty-one professional male volleyball players with no history of Achilles trauma were included in this study. Twenty-one healthy male volunteers with similar ages and body mass indices were selected as control participants. All participants underwent sonographic and elastographic evaluations of the Achilles tendons to evaluate Achilles tendon thickness and stiffness.

RESULTS

We observed thickening in many of the thirds of the Achilles tendons (right proximal, right middle, left middle, and left distal thirds) of athletes in comparison with healthy volunteers. We did not detect any abnormalities according to the sonographic evaluations in both athletes and healthy volunteers. In the elastographic evaluations, we observed softening in the middle thirds of the Achilles tendons of athletes according to the main types (P < .001) and subtypes (P < .001 for right; and P = .002 for left middle third). There was no difference observed in the elastographic evaluations of the proximal and distal thirds.

CONCLUSIONS

On sonography and elastography, we observed thickening and softening in Achilles tendons of athletes in comparison with healthy volunteers who had similar ages and body mass indices. These changes could be associated with early tendon degeneration. Further longitudinal studies may support this consideration.

Liver Stiffness and Serum Alpha-Fetoprotein in Discriminating Small Hepatocellular Carcinoma from Cirrhotic Nodule

AIM

This study aimed to investigate the clinical significance of liver stiffness and serum alpha-fetoprotein (AFP) in differentiating small hepatocellular carcinoma (HCC) from cirrhotic nodule.

METHODS

A total of 95 chronic hepatitis B patients who were diagnosed with small HCC (n = 53) or cirrhotic nodule (n = 42) underwent ultrasound elastography point quantification (ElastPQ) examinations on lesion and background liver. Three stiffness parameters, lesion stiffness value (SV), absolute stiffness difference (ASD) of lesion and background liver, stiffness ratio (lesion/background liver) (SR), and serum AFP were retrospectively analyzed. Then, the capabilities of lesion SV, ASD, SR, AFP, and the combination of each individual stiffness parameter with AFP were evaluated in differentiating small HCC from cirrhotic nodule.

RESULTS

Significantly higher lesion SV, ASD, SR, and serum AFP were observed in small HCC compared with cirrhotic nodule patients (all P ≤ 0.0001). By comparing the stiffness parameters on the patients with AFP greater than 20 ng/mL and AFP of 20 ng/mL or smaller, a higher lesion SV and comparable ASD and SR were found in the small HCC patients. The diagnostic accuracy of lesion SV, ASD, SR, and AFP in the discrimination of small HCC and cirrhotic nodule was 0.731, 0.825, 0.820, and 0.789, respectively. Moreover, the improved sensitivity was observed in the combination of liver stiffness with AFP (83%, 100%, and 92% for lesion SV/AFP, ASD/AFP, and SR/AFP, respectively).

CONCLUSIONS

This study illustrated that the combination of liver stiffness and serum AFP has considerable clinical value in detecting suspicious small HCC from cirrhotic nodule.

Muscle elastography: a new imaging technique for multiple sclerosis spasticity measurement

Multiple sclerosis (MS) spasticity is currently evaluated on the basis of neurological examinations such as Ashworth Scale (AS) and 0-10 NRS. Severity of spasticity is difficult to quantify. We investigated the use of real time elastography (RTHE) ultrasounds for evaluating objectively the muscle fibers status in MS spasticity patients and their changes after a new antispasticity treatment. Two studies were performed. In study A, 110 MS patients underwent a neurological evaluation based on the AS and RTHE. The RTHE images were scored with the new 1-5 muscle fibers rigidity imaging scale, here called MEMSs (Muscle Elastography Multiple Sclerosis Score). The correlation between AS and MEMSs was found to be statistically significant. In study B, 55 MS patients treated with THC:CBD oromucosal spray for their resistant spasticity were followed prospectively. MS spasticity was evaluated by the 0-10 NRS scale at baseline and after 4 weeks of treatment. MEMSs' figures were obtained at both timepoints. Responders to THC:CBD oromucosal spray (pre-defined as an improvement ≥20% in their 0-10 NRS spasticity score vs. baseline) were 65% of sample. These patients had a mean 0-10 NRS reduction of 1.87 and a MEMSs reduction of 1.97 (P values <0.0001). The remaining 35% of patients, classified as clinically non-responders, showed still a significant mean reduction in MEMSs (0.8, P = 0.002). Our overall results showed that RTHE, operativized throughout MEMSs, could be an objective gold standard to evaluate MS muscle spasticity as well as the effectiveness of antispasticity therapy.

Assessment of forearm muscle spasticity with sonoelastography in patients with stroke

OBJECTIVE

The aim of the study was to investigate the feasibility of sonoelastography to show muscle stiffness in post-stroke spasticity, and the relationship between sonoelastography findings and clinical spasticity scores in the spastic forearm muscles.

METHODS

This study was carried out in a university rehabilitation centre. 23 patients with stroke with forearm muscle spasticity (≥1+ using the Modified Ashworth scale score and ≥1 using the Tardieu scale) were included. Sonoelastography parameters (elasticity index and elasticity ratio) were measured from the flexor digitorum superficialis, flexor digitorum profundus, flexor carpi radialis and flexor carpi ulnaris muscles on the affected and unaffected sides.

RESULTS

Both elasticity index and elasticity ratio of the wrist and finger flexors on the hemiplegic side were significantly increased compared with those on the healthy side (p < 0.05). The Tardieu angle of finger flexors was negatively correlated with the elasticity index and elasticity ratio measured in the spastic flexor digitorum profundus (r = -0.418 and r = -0.469, respectively). Tardieu angle of finger flexors was negatively correlated with the elasticity index measured in the spastic flexor digitorum superficialis (r = -0.435). There was no correlation between other parameters.

CONCLUSION

Sonoelastography may provide objective assessment of spasticity both in diagnosis and follow-up. To strengthen this prediction, further studies are necessary. Advances in knowledge: The results of this study represent that sonoelastography is a promising evaluation method for forearm muscle spasticity.

Ultrasound Vascular Elastography as a Tool for Assessing Atherosclerotic Plaques - A Systematic Literature Review

Atherosclerosis is a widespread disease that accounts for nearly 3-quarters of deaths due to cardiovascular disease. Ultrasound elastography might be able to reliably identify characteristics associated with vulnerable plaques. There is a need for the evaluation of elastography and its ability to distinguish between vulnerable and stable plaques. The aim of this paper is to provide an overview of the literature on vascular elastography. A systematic search of the available literature for studies using elastography for assessing atherosclerotic plaques was conducted using the MEDLINE, Embase, Cochrane Library and Web of Science databases. A standardized template was used to extract relevant data following the PRISMA 2009 checklist. 20 articles were included in this paper. The studies were heterogeneous. All studies reported that elastography was a feasible technique and provided additional information compared to B-mode ultrasound alone. Most studies reported higher strain values for vulnerable plaques. Ultrasound elastography has potential as a clinical tool in the assessment of atherosclerotic plaques. Elastography is able to distinguish between different plaque types, but there is considerable methodological variation between studies. There is a need for larger studies in a clinical setting to determine the full potential of elastography.

Shear Wave Elastography of Focal Liver Lesion: Intraobserver Reproducibility and Elasticity Characterization

PURPOSE

The aim of the study was to evaluate the intraobserver reproducibility and to determine the elasticity characteristics of focal liver lesions (FLLs) by shear wave elastography (SWE).

METHODS

One hundred thirty-six FLLs in 118 patients were examined with SWE for quantitative and qualitative assessment of stiffness. Three SWE images were obtained for each lesion and liver parenchyma by 1 radiologist. Intraobserver reproducibility was assessed by intraclass correlation coefficients (ICCs). Patient and lesion factors that can affect the reproducibility were evaluated. For characterization of the lesion elasticity, the difference in stiffness between the groups of lesions was evaluated.

RESULTS

The mean (SD) diameter and depth of the lesions were 3.98 (2.07) and 4.4 (1.59) cm, respectively. The ICC of intraobserver reproducibility was 0.763. Deep-seated lesions (≥6 cm; ICC, 0.621) showed significantly lower intraobserver reproducibility compared with superficial lesions (ICC, 0.793; P = 0.047). Stiffness values of malignant lesions (n = 85, 60.41 [47.81] kPa) were significantly higher than those of benign lesions (n = 51, 22.05 [17.24] kPa, P < 0.0001). Mean (SD) stiffness of hepatocellular carcinoma (45.72 [35.65] kPa) was significantly lower than that of metastasis (67.43 [43.39] kPa) and was significantly higher than benign FLLs (22.05 [17.24] kPa). However, mean (SD) lesion-parenchyma ratio of hepatocellular carcinoma (3.76 [4]) was not significantly different from that of benign FLLs (3.7 [3.77]).

CONCLUSIONS

Overall, intraobserver reproducibility of SWE in evaluation of FLLs was excellent, but it can be affected by lesion depth. In addition, SWE is helpful in elasticity characterization of FLLs.