Strain elastography features of epidermoid tumours in superficial soft tissue: differences from other benign soft-tissue tumours and malignant tumours

Sonographic and elastographic findings after arthroscopic rotator cuff repair: a comparison with clinical results

OBJECTIVE

We assessed the relationship between early postoperative clinical outcomes of arthroscopic rotator cuff repair (ARCR) and observations obtained by postsurgical ultrasound (US) and strain elastography (SE) of repaired supraspinatus tendons (SSTs).

METHODS

This retrospective study included 42 cases in which the patient underwent ARCR followed by postoperative US and SE. The Korean Shoulder Scoring (KSS) system was used to assess preoperative and postoperative conditions. The thickness of the repaired SST and subdeltoid fluid was measured by US. SE scores were classified into four grades (1 to 4) according to elasticity of repaired SST. In addition, SE scores were divided into two groups: soft (SE scores of 1 and 2) and hard (SE scores of 3 and 4). The relationship between clinical outcomes and US parameters and SE scores was determined by KSS.

RESULTS

Postoperative SE scores observed by two readers correlated significantly with function (p = 0.021 and p = 0.021, respectively) and muscle strength (p = 0.008 and p = 0.015, respectively). SE scores were significantly correlated with a difference value of muscle strength of KSS scores (p = 0.002 and p = 0.014). In a comparison of hard and soft groups of repaired SSTs, function (p = 0.008 and p = 0.010, respectively) and muscle strength (p = 0.002 and p = 0.014, respectively) in postoperative KSS scores were statistically higher in the hard SE scores than the soft SE scores. The difference value of function (p = 0.021 and p = 0.021,) and muscle strength (p = 0.008 and p = 0.015) of KSS scores was significantly higher in the hard SE scores.

CONCLUSIONS

Postoperative SE scores of repaired tendons correlated significantly with muscle strength and function after ARCR. Postoperative US images including thickness of repaired tendon and subdeltoid fluid did not correlate with clinical outcome.

ADVANCES IN KNOWLEDGE

SE evaluations of repaired SST may provide important information about postoperative muscle strength and function.

Sarcoma Imaging Surveillance

Soft tissue sarcomas (STS) are a heterogeneous group of solid tumors. There are many histologic subtypes. The prognosis after treatment may be estimated by the analysis of the type of tumor, grade, depth, size at diagnosis, and age of the patient. These type of sarcomas most commonly metastasize to the lungs and may have a relatively high rate of local recurrence, depending on the histologic type and surgical margins. Patients with recurrence have a poorer prognosis. The surveillance of patients with STS is therefore extremely important. This review analyzes the role of MR imaging and US in detecting local recurrence.

Ultrasonographic and strain elastographic features of epidermal cyst according to body location

BACKGROUND

There are not many studies on the differences of ultrasound (US) findings between epidermal cysts (ECs) located in the trunk and those in the extremities.

PURPOSE

To compare the sonographic findings of ECs according to location in the body (trunk vs. extremity) and evaluated the feasibility of strain elastography (SE).

MATERIAL AND METHODS

This is a retrospective study of 76 patients with surgically confirmed non-ruptured EC who underwent US including SE. The US analyses included size, shape, ratio of depth to length (DLR), involvement of more than half the dermis, "submarine sign," and SE characters of each lesion. SE findings were assigned into four grades based on elasticity.

RESULTS

The submarine sign was more significantly observed in ECs located in the trunk versus extremities (P value = 0.004 and 0.035, respectively). Truncal lesions were significantly more likely to possess an ovoid shape (P < 0.05) and exhibited higher DLR (P < 0.05). There were more cases with low elasticity according to SE (grade 3 or 4) compared to high elasticity (grade 1 or 2). However, we did not observe significant differences between the two locations (P > 0.05). More-than-half signs also did not exhibit a significant difference (P > 0.05).

CONCLUSION

The submarine sign, ovoid shape, and tall lesions (higher DLR) are common in the trunk. However, the degree of elasticity and number of more-than-half signs did not differ between the two groups.

The reproducibility of shear wave and strain elastography in epidermal cyst

Purpose

This study evaluated epidermal cyst elasticity using multiple parameters of strain elastography (SE) and shear wave elastography (SWE) and assessed the reproducibility of each parameter.

Methods

This retrospective study included 73 patients with epidermal cysts who underwent SE and SWE. SE scores were classified as 1-4 according to elasticity. The strain ratio was evaluated using the elasticity ratio of lesions and adjacent subcutaneous fat tissue. For SWE, the shear wave velocity (m/s), elasticity (kPa) according to the Young modulus, velocity ratio, and elasticity ratio were evaluated. All values were measured twice. The reproducibility of SE and SWE measurements was assessed. The relationships among SE and SWE measurements were evaluated.

Results

The strain ratio on SE images showed good reproducibility (intra-class correlation coefficient [ICC]=0.789), and SE scores showed substantial reproducibility (kappa=0.753 and kappa=0.758 for readers 1 and 2, respectively). Moderate reproducibility was found for shear wave velocity and elasticity (ICC=0.750 and ICC=0.648, respectively), as well as for the shear wave velocity of the reference tissue and velocity ratio (ICC=0.747 and ICC=0.713, respectively). All SE scores were positively correlated with the strain ratio (P<0.001). The strain ratio in the second SE session was significantly correlated with the elasticity ratio and velocity ratio in the first SWE session (r=0.245, P=0.037; r=0.243, P=0.038, respectively). Other variables were not correlated.

Conclusion

SE and SWE parameters of epidermal cysts showed moderate to good reproducibility. The strain ratio on SE showed good reproducibility and could provide relatively objective and consistent measurements of epidermal cyst elasticity.

REAL-TIME strain elastography: Applications in musculoskeletal system

BACKGROUND

Strain or compression sonoelastography (CE) provides a colour-coded elastogram representing tissue elasticity by measuring tissue deformability after repeated probe compression. Elastographic ultrasound (EUS) is a valuable tool for screening diagnosis and follow-up of inflammatory, degenerative, benign and malignant neoplastic pathologies of skin, subcutaneous tissue, muscles, tendons, ligaments, fascia and nerves; help in targeted biopsy; monitor healing tendons after surgery or nerve stiffness changes during physiotherapy.

OBJECTIVES

To assess stiffness of normal tendons, muscles and nerve. To diagnose cellulitis, fasciitis, abscess, tendinopathy, myositis, muscle/tendon rupture/contusion and differentiate between benign and malignant soft tissue tumours. To derive elastic score (ES) and strain ratio (SR) in cases and controls. To correlate B-mode findings with CE.

MATERIALS AND METHODS

A prospective study on 50 healthy subjects between 25 and 30 years and 50 cases of diffuse and focal musculoskeletal pathologies was done using B-mode and CE over 2 years. Statistical analysis of distribution, mean, associations, sensitivity, specificity, area under Receiver Operating Characteristic curve (AUROC) for B-mode, ES, SR combined B-mode/CE and their comparison was done.

RESULTS

Significant association was noted between SR in muscles and tendons with sex. Significant correlation was noted between ES/SR with B-mode. CE and B-mode had 100% and 52.4% sensitivity respectively for diagnosing diffuse pathologies. For differentiating benign and malignant masses sensitivity, specificity, and diagnostic accuracy of B-mode was 71.43%, 86.36% and 82.76%; of SR was 71.43%, 90.91% and 86.21%; of Combined B-mode with CE was 100%, 90.91% and 93.1% respectively. Elastographic pattern had highest diagnostic accuracy and largest AUROC.

CONCLUSION

CE as a screening test had higher diagnostic accuracy, supporting need for standardizing it for clinical use in MSK. EUS being a widely available, fast and affordable modality, can aid follow up of chronic MSK pathologies, response to medication, physiotherapy and surgery and mitigate the need for MRI.

Sonographic and Strain Elastographic Findings of a Clear Cell Hidradenoma that Looked Like an Epidermoid Tumor: A Case Report

Clear cell hidradenoma (CCH) is a rare tumor of the sweat glands of eccrine or apocrine differentiation. It can occur anywhere in the body, but common sites of involvement are the head, face, trunk, and extremities. Although several reports have described sonographic findings of CCH, only one study on the axilla mentioned its strain elastographic findings. Here, we present a case of CCH in the right calf with its sonographic and strain elastographic findings in a tumor that looked like an epidermoid tumor.

The diagnostic performance of conventional ultrasound and strain elastography in malignant soft tissue tumors

OBJECTIVE

To investigate the diagnostic value of conventional ultrasound (US) and strain elastography (SE) in malignant soft tissue tumors.

METHOD

A total of 83 soft tissue masses were included prospectively. US and SE imaging were performed at the same time. Two observers assessed the B mode, color Doppler, elastic scores (ES), strain ratio (SR), and SE size to B mode size (EI/B) ratio and compared the consistency of the data between the observers. According to the pathological diagnosis of resection, the cases were divided into malignant and nonmalignant groups. The diagnostic value of conventional US and SE in the prediction of malignant soft tissue tumors was assessed.

RESULTS

The pathology results divided cases into 36 malignant lesions and 47 nonmalignant lesions. There was no statistically significant difference in gender, location, maximum diameter, echo, tail sign, cystic component, Doppler scores, or SR between the two groups (p > 0.05). However, significant differences between the two groups were found in age, depth, heterogeneity, edge, ES, and EI/B (p < 0.05). The biggest area under the receiver operating characteristics curve (0.934) was the combination model of age, heterogeneity, edge, ES, and EI/B, and the sensitivity and specificity were 0.861 and 0.957, respectively.

CONCLUSIONS

Conventional US and SE are significant for the diagnosis of malignant soft tissue tumors, and SE can be used as a complementary technique to the characterization of STTs using conventional US.

Usefulness of strain elastography in the differential diagnosis of ruptured epidermal cyst and superficial abscess

PURPOSE

The aim of this study was to evaluate the usefulness of strain elastography (SE) in the differential diagnosis of ruptured epidermal cyst and superficial abscess.

METHODS

This retrospective study included 34 patients with ruptured epidermal cysts and 17 patients with superficial abscesses who underwent ultrasonography (US) including SE. The SE characteristics were classified into four grades (1 to 4) according to elasticity. The largest length and height of the lesion and their ratio were evaluated on the US images. Involvement of more than half of the depth of the dermis and the presence of the submarine sign were assessed.

RESULTS

The inter-reader agreement of US and SE findings showed excellent or almost perfect agreement. The height, length, ratio of height to length, and more-than-half-depth sign did not significantly differ between ruptured epidermal cysts and superficial abscesses for either reader (reader 1, P=0.071, P=0.129, P=0.806, and P=0.102, respectively; reader 2, P=0.173, P=0.053, P=0.669, and P=0.060, respectively). The submarine sign was significantly more frequent in ruptured epidermal cysts than in superficial abscesses (both readers, P<0.001). The difference in SE scores between ruptured epidermal cysts and superficial abscesses, which are harder than ruptured epidermal cysts, was statistically significant (reader 1, P=0.046; reader 2, P=0.028).

CONCLUSION

The SE score and submarine sign may be useful characteristics for distinguishing ruptured epidermal cyst from superficial abscess.

Can ultrasound distinguish between dermatofibroma and subcutaneous epidermal tumors? - Imaging features and reproducibility

BACKGROUND

We evaluated ultrasound (US) features of dermatofibroma and epidermal tumor (ET). We also evaluated the reproducibility of each US findings.

MATERIALS AND METHODS

We retrospectively assessed US findings of 30 surgically confirmed dermatofibromas and 44 ETs, measuring the lesion (i.e., the depth and the length of the lesion) and calculating the depth to length ratio (DLR). We then determined the sharpness and the shape of the lesion. Finally, we assessed whether the lesion appeared with a "more-than-half sign" (involving more than 50% of the dermal layer) or a "submarine sign" (focal projection to skin). We used Pearson's chi-squared test to analyze the US findings (i.e., presence of more-than-half sign or submarine sign and margin sharpness) between dermatofibroma and ET. Inter-observer agreement of the image findings was assessed using kappa statistics.

RESULTS

The submarine sign and margin sharpness of ET lesions and the more-than-half sign and submarine sign in dermatofibroma, respectively, showed almost perfect agreement. Also, the more-than-half sign and shape of the lesion in ET and the margin sharpness and shape of the lesion in dermatofibroma showed substantial agreement. The measurements of DLRs showed excellent reproducibility. There were no significant differences of DLRs between two groups (p values = 0.512, 0.671, respectively). The more-than-half sign was observed more frequently in the context of dermatofibroma to a statistically significant degree (p < 0.001), while the submarine sign was statistically more common in relation to ET together with greater margin sharpness (p = 0.021 and <0.001, respectively).

CONCLUSIONS

More-than-half signs are common in dermatofibroma while submarine sign and sharp margin are common in ET. Each finding showed high reproducibility and can be useful as a sonographic marker for differentiation between ET and dermatofibroma.

Strain elastography for the assessment of skin nodules in dogs

BACKGROUND

Strain elastography (SE) is a modern imaging technology that provides an additional way of evaluating the changes in soft tissue elasticity caused by pathophysiological processes. Despite its widespread use in human medicine, only a few studies on the application of SE in veterinary medicine are available.

OBJECTIVES

To evaluate the potential usefulness of SE as an integrative imaging model in the standard ultrasound technique to better discriminate between inflammatory and neoplastic skin nodules in dogs.

ANIMALS

Fifty-one client-owned dogs with clinical evidence of single or multiple skin nodules detected during routine dermatological examination.

METHODS AND MATERIALS

Margins, echogenicity, echo-structure, calcification and vascularisation of 65 skin nodules were assessed with ultrasound, and SE was used to score qualitative (E-score, E-index, E2) and semiquantitative (SR) parameters. A comparison of diagnostic yields with cytological and histological findings as the gold standard was performed.

RESULTS

Mast cell and benign follicular tumours showed the highest E-scores and SRs among neoplastic nodules; statistically significant differences were not detected. Calcific and nonvascularised nodules showed significantly higher E-index values than the others. Overall, a negative correlation was observed between the longitudinal diameter of skin nodules and the qualitative elastic parameters.

CONCLUSIONS AND CLINICAL IMPORTANCE

In this study, SE proved to be useful to identify only a subset of nodules such as mast cells and hair follicular tumours. Although evidence supporting the use of SE in evaluating skin nodules was demonstrated to below, indicators to guide further research were developed.

Diagnostic Performance of Elastography in Malignant Soft Tissue Tumors: A Systematic Review and Meta-analysis

Malignant soft tissue tumors (STTs) are often mistaken for benign tumors, leading to inappropriate treatment including unplanned resection. Elastography, as a non-invasive measurement of tissue mechanical properties, makes use of the different soft tissue elasticity in diverse pathologies to generate information that can be used for diagnostic purposes. Elastography for STTs carries important information that is helpful in differentiating malignant and benign masses. The present study was undertaken to systematically review existing trials on the reliability of elastography in assessment of malignant STTs. A comprehensive literature exploration of the PubMed, EMbase and China National Knowledge Infrastructure databases was conducted for published articles involving the application of elastography in distinguishing malignant STTs. The diagnostic performance of elastography was evaluated with pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under the summary receiver operating characteristic curve. Publication bias was also evaluated. This meta-analysis enrolled 18 eligible studies with a total of 1420 patients. The overall number of reported STTs was 1569, of which 478 were classified as positive and 1091 as negative at elastography. The pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of elastography were 0.82 (95% confidence interval: 0.74-0.87), 0.80 (0.71-0.86), 3.99 (2.65-6.01) and 0.23 (0.15-0.34), respectively. The diagnostic odds ratio and area under the curve were 17.36 (8.28-36.38) and 0.88 (0.84-0.90), respectively (Glas et al. 2003). The results of meta-regression analysis revealed that the total number of patients and prevalence of malignant STTs were significant factors in sensitivity, and the year of publication, total number of patients and index test were significant factors affecting study heterogeneity for specificity (p < 0.05). No significant publication bias was observed. This meta-analysis indicates that ultrasound elastography achieves relatively good performance in discriminating between malignant and benign STTs. Nevertheless, further research is needed to verify this finding.

Distinction between benign and malignant soft tissue tumors based on an ultrasonographic evaluation of vascularity and elasticity

The initial diagnostic distinction between benign and malignant soft tissue tumors is critical for decisions regarding the appropriate course of treatment. The current study aimed to evaluate the vascularity and elasticity of soft tissue tumors by superb microvascular imaging and shear wave elastography using ultrasonography (US), to determine their usefulness in distinguishing malignant soft tissue tumors, and to further establish the diagnostic accuracy and usefulness of a scoring system (SS) based on these evaluations. The present study used 167 lesions of soft tissue tumors examined by US prior to biopsy, surgery and pathological tissue diagnosis. The vascularity index (VI) and the maximal shear velocity (MSV), as indices of vascularity and elasticity respectively, were evaluated using US. The tumor size and depth were also evaluated via magnetic resonance imaging (MRI). Based on the odds ratio of these parameters determined by multivariate logistic regression analysis, an original SS was established to identify the malignancy of soft tissue tumors. VI and MSV exhibited significantly high values for malignant tumors. Tumor size was also significantly larger for malignant than benign tumors. The areas under the curves (AUCs) of the receiver operating characteristic analysis for VI, MSV and tumor size were 0.75, 0.84 and 0.69, respectively, indicating that these methods were effective for the diagnosis of malignancy. An original SS consisting of VI, MSV and tumor size, excluding tumor depth, was established, and revealed an AUC value of 0.90, with 93.6% sensitivity and 79.2% specificity for malignancy distinction. US evaluation of vascularity and elasticity was an effective technique to distinguish malignant soft tissue tumors, and the current SS based on US evaluations including tumor size via MRI demonstrated a high diagnostic accuracy for malignant soft tissue tumors.

The diagnostic value of ultrasound and shear wave elastography in the differentiation of benign and malignant soft tissue tumors

AIM

To evaluate the diagnostic value of ultrasound (US) and shear wave elastography (SWE) in the differentiation of benign and malignant soft tissue tumors.

MATERIALS AND METHODS

A hundred and nine patients (mean age 43.3 ± 20.5, range 0-85; 64 men and 45 women) diagnosed with soft tissue tumors between August 2016 and January 2020 were evaluated with US and SWE. The stiffness of the lesions was measured as mean and maximum shear wave velocity (SWV_mean and SWV_max) in meters/second (m/s). Two radiologists evaluated the US images independently and then reached a final consensus. Final diagnosis was obtained either by histopathological examination (core needle biopsy or surgery) or by follow-up. The diagnostic value of US and SWE in the differentiation of malignant and benign lesions was assessed.

RESULTS

Pathology results revealed 37 malignant and 43 benign lesions. Twenty-nine lesions were benign based on follow-up criteria. Consensus US reading revealed 91.9% sensitivity and 72.2% specificity with almost perfect inter-observer agreement (κ = 0.802). Larger lesion size, male gender, advanced patient age, deep location, hypoechoic and hypervascular appearance, ill-defined margins, and presence of cystic area were associated with malignant diagnosis (p < 0.001, p = 0.010, p = 0.001, p = 0.001, p = 0.003, p < 0.001, p = 0.001, and p = 0.011, respectively). Median SWV_mean and median SWV_max of malignant lesions (2.87 and 2.68) were not significantly different than those of the benign lesions (3.30 and 3.05; p = 0.271 and p = 0.402, respectively).

CONCLUSION

US features can differentiate malignant and benign soft tissue tumors, whereas SWE did not contribute to the differentiation of soft tissue tumors.

Diagnostic accuracy of an integrated approach using conventional ultrasonography, and Doppler and strain elastography in the evaluation of superficial soft tissue lesions

Purpose

To assess the diagnostic accuracy of an integrated approach using conventional ultrasonography, colour Doppler ultrasonography, and elastography strain ratios in tandem in the evaluation of superficial soft tissue lesions.

Material and methods

Sixty-five subjects were included in this prospective cross-sectional study. Greyscale features and Doppler parameters were recorded. Strain elastography of the non-vascular and non-cystic lesions was performed and strain ratios were calculated. Fine-needle aspiration or biopsy of all the lesions was performed depending on their site and condition. Inter-rater k agreement was used to determine the strength of agreement between imaging-based diagnosis and histopathological diagnosis. A diagnostic test was used to calculate the sensitivity, specificity, positive predictive value, and negative predictive value. A p value of < 0.05 was considered statistically significant.

Results

Multiple superficial soft tissue lesions were studied, the majority of which were lipomas, vascular anomalies, and epidermoid cysts. The diagnostic accuracy was very high and varied from 92.31% to 100% for various masses. The imaging-based diagnosis was in agreement with the histopathological diagnosis in 86.15% (n = 56) and disagreement in 13.85% (n = 9) of the cases (p < 0.007). There was very good inter-rater agreement between the imaging-based diagnosis and histopathological diagnosis (κ = 0.818).

Conclusions

The combined use of conventional ultrasonography, colour Doppler, and elastography strain ratios provides a very effective non-invasive tool for the diagnosis of superficial soft tissue lesions and may negate the need for unnecessary biopsies. The advantage of this integrated approach using various ultrasound techniques needs no further emphasis.

Inter- and intra-reader reproducibility of shear wave elastography measurements for musculoskeletal soft tissue masses

OBJECTIVE

To determine inter- and intra-reader reproducibility of shear wave elastography measurements for musculoskeletal soft tissue masses.

MATERIALS AND METHODS

In all, 64 patients with musculoskeletal soft tissue masses were scanned by two readers prior to biopsy; each taking five measurements of shear wave velocity (m/s) and stiffness (kPa). A single lesion per patient was scanned in transverse and cranio-caudal planes. Depth measurements (cm) and volume (cm³) were recorded for each lesion, for each reader. Linear mixed modelling was performed to assess limits of agreement (LOA), inter- and intra-reader repeatability, including analyses for measured depth and volume.

RESULTS

Of the 64 lesions scanned, 24 (38%) were malignant. Bland-Altman plots demonstrated negligible bias with wide LOA for all measurements. Transverse velocity was the most reliable measure-intraclass correlation (95% CI) = 0.917 (0.886, 1)-though reader 1 measures could be between 38% lower and 57% higher than reader 2 [ratio-scale bias (95% LOA) = 0.99 (0.64, 1.55)]. Repeatability coefficients indicated most disagreement resulted from poor within-reader reproducibility. LOA between readers calculated from means of five repeated measurements were narrower-transverse velocity ratio-scale bias (95% LOA) = 1.00 (0.74, 1.35). Depth affected both estimated velocity and repeatability; volume also affected repeatability.

CONCLUSION

This study found poor repeatability of measurements with wide LOA due mostly to intra-reader variability. Transverse velocity was the most reliable measure; variability may be affected by lesion depth. At least five measurements should be reported with LOA to assist future comparability between shear wave elastography systems in evaluating soft tissue masses.

A bump: what to do next? Ultrasound imaging of superficial soft-tissue palpable lesions

Soft-tissue palpable lesions are common in clinical practice, and ultrasound (US) represents the first imaging option in the evaluation of a patient with a soft-tissue swelling. A full and systematic US assessment is necessary, however. This includes grayscale, color- and power-Doppler, spectral-Doppler, and possibly elastography facilities, as well as a trained operator. Several lesions showing characteristic US features can be diagnosed confidently, without any further work-up, and the high spatial resolution of ultrasound in the superficial layers can be a powerful tool to discriminate their etiologies. Second-level options, to be reserved for indeterminate cases or those suspected malignant at initial ultrasound, include magnetic resonance imaging, percutaneous fine-needle aspiration or biopsy, and surgical-excision biopsy. In this article, we discuss the proper US approach for addressing superficial soft-tissue lesions.

Shear Wave Elastography in the Diagnosis of Hand Tumours

Diagnosis of hand tumours by conventional imaging remains difficult. Shear wave elastography (SWE) is a noninvasive method used to quantitatively assess the mechanical properties of tissues. We provide the first report of "histoelastographic" data concerning a finger tumour. Our data support the notion of ultrasound assessment using multiple parameters including morphology, elasticity, viscosity, and microflow vascularization likely contributing towards a more precise diagnosis in the future.

Shear-Wave Elastography of Benign versus Malignant Musculoskeletal Soft-Tissue Masses: Comparison with Conventional US and MRI

Purpose To examine if shear-wave elastography (SWE) improves the accuracy of diagnosing soft-tissue masses as benign or malignant compared with US alone or in combination with MRI. Materials and Methods Two hundred six consecutive adult participants (mean age, 57.7 years; range, 18-91 years), including 89 men (median age, 56.0 years; range, 21-91 years) and 117 women (median age, 59.1 years; range, 18-88 years), who were referred for biopsy of a soft-tissue mass were prospectively recruited from December 2015 through March 2017. Participants underwent B-mode US, MRI, and SWE prior to biopsy. Three musculoskeletal radiologists independently reviewed US images alone, followed by US and MRI images together, and classified lesions as benign, probably benign, probably malignant, or malignant. For SWE, the area under the receiver operating characteristic (ROC) curve (AUC) was calculated for transverse shear-wave velocity (SWV). Multivariable logistic regression was used to investigate the association between SWE and malignancy alongside individual demographic and imaging variables. Results At histologic examination, 79 of 206 (38%) participants had malignant lesions. SWV showed good diagnostic accuracy for lesions classified as benign or probably benign by US alone (AUC = 0.87 [95% confidence interval {CI}: 0.79, 0.95]). SWV did not provide substantive diagnostic information for lesions classified as probably malignant or malignant, whether the classification was made with or without MRI. However, multivariable modeling indicated that diagnostic accuracy may vary by lesion position (interaction P = .02; superficial, odds ratio [OR] = 17.7 [95% CI: 1.50, 207], P = .02; deep/mixed, OR = 0.24 [95% CI: 0.07, 0.86], P = .03) and participant age (interaction P = .01; eg, age 43 years, OR = 0.72 [95% CI: 0.15, 3.5], P = .69; age 72 years, OR = 0.08 [95% CI: 0.02, 0.37], P = .001). Conclusion Shear-wave elastography can increase accuracy of soft-tissue lesion diagnosis in conjunction with US. However, a single cut-off may not be universally applicable with diagnostic accuracy that is affected by lesion position and patient age. © RSNA, 2018 Online supplemental material is available for this article.

Epidermal inclusion cyst with foreign-body giant-cell reaction treated with surgical excision and rotational flap closure: A case report

Epidermal inclusion cysts (epidermoid cysts) occur from penetration of epidermal cells into underlying dermal tissue. They are most commonly found on the scalp, face, neck, and back with a reported incidence of 10% on the extremities. We present the case of a 53-year-old female who presented with complaint of a painful plantar forefoot soft-tissue mass of insidious origin. After magnetic resonance imaging, she was treated with surgical excision and plastic rotational flap closure. The surgical site healed without incident, and she was able to ambulate pain free in her normal footwear with full weight bearing and no shoe modifications or orthotics. This case was novel in that the size of the lesion required the use of a uni-lobe full-thickness rotational skin flap to achieve complete tension-free closure.

The feasibility of shear wave elastography for diagnosing superficial benign soft tissue masses

PURPOSE

The purpose of this study was to investigate the feasibility of shear wave ultrasound elastography for differentiating superficial benign soft tissue masses through a comparison of their shear moduli.

METHODS

We retrospectively analyzed 48 masses from 46 patients from February 2014 to May 2016. Surgical excision, fine-needle aspiration, and clinical findings were used for the differential diagnosis. The ultrasonographic examinations were conducted by a single musculoskeletal radiologist, and the ultrasonographic findings were reviewed by two other radiologists who were blinded to the final diagnosis. Conventional ultrasonographic features and the median shear modulus were evaluated. We compared the median shear moduli of epidermoid cysts, ganglion cysts, and lipomatous tumors using the Kruskal-Wallis test. Additionally, the Mann-Whitney U test was used to compare two distinct groups.

RESULTS

Significant differences were found in the median shear moduli of epidermoid cysts, ganglion cysts, and lipomatous tumors (23.7, 5.8, and 9.2 kPa, respectively; P=0.019). Epidermoid cysts showed a greater median shear modulus than ganglion cysts (P=0.014) and lipomatous tumors (P=0.049).

CONCLUSION

Shear wave elastography may contribute to the differential diagnosis of superficial benign soft tissue masses through a direct quantitative analysis.

Do quantitative and qualitative shear wave elastography have a role in evaluating musculoskeletal soft tissue masses?

Objectives

To determine if quantitative and qualitative shear wave elastography have roles in evaluating musculoskeletal masses.

Methods

105 consecutive patients, prospectively referred for biopsy within a specialist sarcoma centre, underwent B-mode, quantitative (m/s) and qualitative (colour map) shear wave elastography. Reference was histology from subsequent biopsy or excision where possible. Statistical modelling was performed to test elastography data and/or B-mode imaging in predicting malignancy.

Results

Of 105 masses, 39 were malignant and 6 had no histology but benign characteristics at 12 months. Radiologist agreement for B-mode and elastography was moderate to excellent Kw 0.52-0.64; PABAKw 0.85-0.90). B-Mode imaging had 78.8% specificity, 76.9% sensitivity for malignancy. Quantitatively, adjusting for age, B-mode and lesion volume there was no statistically significant association between longitudinal velocity and malignancy (OR [95% CI] 0.40[0.10, 1.60], p=0.193), but some evidence that higher transverse velocity was associated with decreased odds of malignancy (0.28[0.06, 1.28], p=0.101). Qualitatively malignant masses tended to be towards the blue spectrum (lower velocities); 39.5% (17/43) of predominantly blue masses were malignant, compared to 14.3% (1/7) of red lesions.

Conclusions

Quantitatively and qualitatively there is no statistically significant association between shear wave velocity and malignancy. There is no clear additional role to B-mode imaging currently.

Key Points

• Correlation between shear wave velocity and soft tissue malignancy was statistically insignificant

• B-mode ultrasound is 76.9 % sensitive and 78.8 % specific

• Statistical models show elastography does not significantly add to lesion assessment

An evaluation of ocular elasticity using real-time ultrasound elastography in primary open-angle glaucoma

OBJECTIVE

The aim of this study was to compare sonoelastographic findings in the retina-choroid-sclera (RCS) complex and vitreous in glaucomatous and healthy eyes.

METHODS

For this cross-sectional comparative study, 20 patients with primary open-angle glaucoma and 20 healthy volunteers were recruited. Ultrasound elastography measurements were taken with a sonographic scanner of the RCS complex, anterior vitreous (AV), posterior vitreous (PV), retrobulbar fat tissue (RFT), optic disc (OD) and optic nerve (ON) in each eye.

RESULTS

The elasticity index of the RCS complex, RFT, OD, ON, AV and PV was similar in both groups (p  >  0.05), although the AV/PV strain ratio in the group of patients with glaucoma was significantly higher (p  =  0.04).

CONCLUSION

Glaucoma increases the AV/PV strain ratio. In providing reproducible and consistent values, the real-time elastography (RTE) technique may be helpful in elucidating the mechanisms of glaucoma in some aspects.

ADVANCES IN KNOWLEDGE

This study can help to evaluate the elasticity of the RCS complex and vitreous in glaucomatous eyes with RTE.

Usefulness of strain elastography of the musculoskeletal system

Ultrasound elastography is a widely used technique for assessing the mechanical characteristics of tissues. Although there are several ultrasound elastography techniques, strain elastography (SE) is currently the most widely used technique for visualizing an elastographic map in real time. Among its various indications, SE is especially useful in evaluating the musculoskeletal system. In this article, we review the SE techniques for clinical practice and describe the images produced by these techniques in the context of the musculoskeletal system. SE provides information about tissue stiffness and allows real-time visualization of the image; however, SE cannot completely replace gray-scale, color, or power Doppler ultrasonography. SE can increase diagnostic accuracy and may be useful for the follow-up of benign lesions.