Sonoelastography of parotid gland tumours: initial experience and identification of characteristic patterns

Comparative analysis of elastosonography and 18 F-FDG PET/CT in differentiating benign and malignant salivary gland tumors: a systematic review and meta-analysis

PURPOSE

We conducted a systematic review and meta-analysis to assess and compare the diagnostic performance of elastosonography and 18 F-FDG PET/CT in differentiating between benign and malignant salivary gland tumors.

METHODS

Using PICOS criteria, experimental and observational research evaluating elastosonography or 18 F-FDG PET/CT for differentiating benign and malignant salivary gland tumors were included. A systematic search was conducted across PubMed, Embase, Web of Science, Scopus, Cochrane Library, and CINAHL, initially in July 2024 and updated in February 2025. A manual search for relevant gray literature was also performed. Data extraction and risk of bias assessment using QUADAS-2 were conducted independently by reviewers.

RESULTS

A total of 26 studies with 1609 patients were included in the analysis. The pooled sensitivity of elastosonography and 18 F-FDG PET/CT in the differential diagnosis of benign and malignant salivary gland tumors were 0.75 (95% CI 0.65-0.84) and 0.84 (95% CI 0.78-0.90), specificity was 0.79 (95% CI 0.69-0.87) and 0.85 (95% CI 0.69-0.96), respectively. The area under the curve (AUC) for elastosonography and 18 F-FDG PET/CT were 0.83 and 0.92 and there is a statistical difference between the two imaging modalities (Z = 2.77, P < 0.01). Fagan nomogram indicated that when the pre-test probability was set at 20%, the post-test probability for elastosonography and 18 F-FDG PET/CT could increase to 50% and 65%.

CONCLUSION

In differentiating between benign and malignant salivary gland tumors, 18 F-FDG PET/CT exhibits a superior AUC compared to elastosonography, suggesting that, despite its current limited use in the initial workup of salivary gland tumors, there may be a strong argument for its increased adoption in clinical practice. Nevertheless, it is crucial to note that the findings of this meta-analysis rely on studies with limited sample sizes. More extensive prospective studies are warranted to validate these results further.

Systematic review and meta-analysis of the diagnostic performance of lacrimal gland ultrasound elastography in primary Sjögren's syndrome

OBJECTIVE

This research conducted a comprehensive evaluation of the effectiveness of ultrasonic elastography (USE) in detecting lacrimal gland involvement in individuals suffering from primary Sjögren's syndrome (pSS).

METHODS

A comprehensive search was undertaken across multiple databases including PubMed, the Cochrane Library, EMBASE, Wanfang, Web of Science, and the Chinese National Knowledge Infrastructure, to gather relevant literature pertaining to the application of USE in diagnosing pSS from January 1, 2000, to October 1, 2023. Pooled data were used to calculate sensitivity, specificity, and diagnostic odds ratios. Several summary metrics were used to evaluate SWE's performance in detecting pSS, including the area under the receiver operating characteristic curve, diagnostic odds ratios, sensitivities, and specificities.

RESULTS

Five pertinent studies included a total of 273 patients. Shear wave elastography (SWE) demonstrated a pooled sensitivity of 0.88 (95% CI 0.77-0.94) and specificity of 0.94 (95% CI 0.88-0.98), with an area under the receiver operating characteristic curve of 0.97 (95% CI 0.95-0.98). SWE exhibited a positive likelihood ratio of 15.86 (95% CI 6.99-36.00) and a negative likelihood ratio of 0.13 (95% CI 0.07-0.25). No evidence of publication bias was observed (p = 0.70).

CONCLUSION

SWE demonstrates a remarkable degree of precision in detecting lacrimal gland involvement in individuals suffering from pSS.

[Elastography in thyroid nodules]

BACKGROUND

Elastography is an imaging method to examine the elasticity of tissue. In the meantime, various elastography methods have been developed, which are subdivided according to the type of stimulus applied. In principle, a distinction should be made between strain elastography (SE) and shear wave elastography (SWE). Both methods provide another means of assessing thyroid disease in addition to conventional B-mode sonography.

OBJECTIVE

The aim is to provide an overview of elastography techniques including physical basics and their importance in the clarification algorithm of thyroid nodules.

MATERIALS AND METHODS

International guidelines and recent publications on elastography were selectively assessed.

RESULTS

Elastography provides additional information compared to conventional B-mode sonography. The change in shear stiffness is the essential physical mechanism for tissue contrast in all elastograms. In addition to the qualitative assessment of elasticity in SE, quantification is possible with SWE. In the international literature, elastography was analyzed as a single method or in comparison or combination with conventional B-mode sonography and especially with standardization using a risk stratification system (RSS, TIRADS). The results are quite controversial. In nodules with unclear findings on fine-needle biopsy (Bethesda III/IV), the combination of morphologic criteria and elastography improved diagnostic accuracy. In particular, the high negative predictive value of soft nodules represents a relevant added value. This strength of the method can play an important role in the clarification of nodules with intermediate malignancy risk or of unclear FNB results. Elastography has previously only been incorporated into French-TIRADS. Although the procedure is mentioned in the EU-TIRADS as a complementary method, integration has not been described. Limitations of the method are idealized basic assumptions, dependence of manufacturer and examiner, and artifacts.

CONCLUSION

Elastography can be a useful adjunct to standard diagnostic procedures in the evaluation of thyroid nodules, especially in nodules with intermediate risk of malignancy and unclear results on fine needle aspiration.

Early Prediction of Gestational Diabetes Mellitus Using Placental Strain Elastography and Subcutaneous Adipose Tissue Thickness

AIM

The aim of this study is to investigate the efficacy of placental strain ratio values measured by real-time sonoelastography and maternal subcutaneous adipose tissue thickness measured by two-dimensional ultrasonography in predicting gestational diabetes mellitus in the first trimester.

MATERIALS AND METHODS

The population of the study consisted of the first 210 consecutive singleton pregnant women who applied for routine first-trimester screening between the 11th and 14th week of gestation.B-mode subcutaneous adipose tissue thickness sonography and real-time placental strain elastography scanning were performed.All patients underwent 75 g oral glucose tolerance test between the 24th and 28th week of gestation. American Diabetes Association criteria were used in the diagnosis of gestational diabetes mellitus.

RESULTS

It was observed that body mass index (p<0.001), first-trimester fasting blood sugar (p<0.001), subcutaneous adipose tissue thickness (p<0.001), and placental strain ratio value (p<0.001) affected the development of gestational diabetes mellitus statistically. The multivariate analysis shown that subcutaneous adipose tissue thickness (odds ratio=1.271, 95% CI=1.142-1.416, p<0.001) and placental strain ratio value (odds ratio=3.664, 95% CI=1.927-6.969, p<0.001) were the independent risk factors affecting the development of gestational diabetes mellitus.

CONCLUSIONS

The findings of this study indicated a positive correlation between 75 g oral glucose tolerance test application and first trimester subcutaneous adipose tissue thickness and placental strain ratio. Using the cut-off values of>11.5 mm for subcutaneous adipose tissue and>0.986 for placental strain ratio, the development of gestational diabetes mellitus may be predicted in the early weeks of pregnancy.

Contrast-Enhanced Ultrasound and Strain Elastography for Differentiating Benign and Malignant Parotid Tumors

OBJECTIVES

Preoperative differentiation between benign parotid tumors (BPT) and malignant parotid tumors (MPT) is crucial for treatment decisions. The purpose of this study was to investigate the benefits of combining contrast-enhanced ultrasound (CEUS) and strain elastography (SE) for preoperative differentiation between BPT and MPT.

METHODS

A total of 115 patients with BPT (n=72) or MPT (n=43) who underwent ultrasound (US), SE, and CEUS were enrolled. US and CEUS features and the elasticity score were evaluated. Receiver operating characteristic curve (ROC) analysis was used to assess the diagnostic performance of SE, CEUS, and SE + CEUS with respect to identifying MPT from BPT.

RESULTS

Solitary presentation, larger diameter, irregular shape, ill-defined margin, heterogeneous echogenicity, and calcification on US and higher elasticity score on SE had a significant association with malignancy. MPT also presented an unclear margin, larger size after enhancement, and "fast-in and fast-out" pattern on CEUS. The combination of SE and CEUS was effective for differentiating MPT from BPT (AUC: 0.88, 0.80-0.95), with a sensitivity of 86.0%, specificity of 88.9%, and accuracy of 87.8%, which were significantly higher than the values for SE (AUC: 0.75, 0.66-0.85) and CEUS (AUC: 0.82, 0.73-0.91) alone.

CONCLUSION

The combination of CEUS and SE is valuable for distinguishing MPT from BPT.

Lacrimal gland ultrasonography and elastography as a diagnostic and activity tool for primary Sjögren's syndrome

OBJECTIVE

To investigate the effectiveness of 2-dimensional shear wave elastography (2D-SWE) in the assessment of lacrimal gland involvement in primary Sjögren's syndrome (pSS) and to determine the association between ultrasonographic findings and clinical activity measures.

METHOD

Forty-six patients who fulfilled the 2016 American College of Rheumatology/European League Against Rheumatism (EULAR) classification criteria of pSS and 23 age and gender-matched healthy control subjects were enrolled. Clinical, laboratory and labial biopsy histopathologic characteristics of patients were recorded. Disease activity of pSS and severity of ocular dryness were evaluated with EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) and Ocular Surface Disease Index (OSDI), respectively. Parotid and lacrimal gland architectures were assessed by B-mode ultrasound and 2D-SWE techniques.

RESULTS

Mean shear wave elastography measurements, reflecting loss of elasticity, were remarkably higher in pSS patients compared to healthy subjects both in the lacrimal and parotid glands (8.99 ± 3.45 vs 3.68 ± 1.76 in lacrimal glands and 14.14 ± 4.39 vs 7.83 ± 1.69 in parotid glands, all P < 0.001). Shear wave elasticity of lacrimal glands was correlated with OSDI and ESSPRI scores (r = 0.69; P = 0.001 and r = 0.58; P = 0.001, respectively). A cut-off value of 4.6 kPa in the lacrimal gland elasticity discriminated pSS patients from healthy subjects with a sensitivity of 94% and specificity of 87%.

CONCLUSION

Results of our study suggest that lacrimal glands lose elasticity in patients with pSS and the assessment of elasticity with 2D-SWE might help to classify patients as having pSS. Further studies are needed to validate the diagnostic utility of lacrimal 2D-SWE by including diseases other than pSS.

Diagnostic performance of elastosonography in the differential diagnosis of benign and malignant salivary gland tumors: A meta-analysis

Purpose

The clinical practice of elastosonography for the detection of salivary gland tumors is still a controversial issue. The objective of this meta-analysis was to evaluate the effect of elastosonography for the diagnosis of salivary gland tumors and to compare the diagnostic value of elastosonography and conventional ultrasound in the diagnosis of salivary gland tumors.

Methods

A comprehensive literature search through PubMed, EMBASE, and Cochrane Library was carried out from inception to November 2021. Two researchers independently extracted the data from the enrolled papers using a standard data extraction form. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were calculated to evaluate the diagnostic performance of elastosonography. The Quality Assessment of Diagnostic Accuracy Studies—2 (QUADAS-2) tool was utilized to evaluate the quality of each included study. Meta-DiSc version 1.4, Review Manager 5.3, and StataSE 15 were used.

Results

Sixteen studies with a total of 1105 patients with 1146 lesions were included in this meta-analysis. The pooled sensitivity, specificity, PLR, NLR, and DOR of elastosonography for the differentiation between benign and malignant salivary gland tumors were 0.73 (95%CI, 0.66–0.78), 0.64 (95%CI, 0.61–0.67), 2.83 (95%CI, 1.97–4.07), 0.45 (95%CI, 0.32–0.62), and 9.86 (95%CI, 4.49–21.62), respectively, with an AUC of 0.82. Four studies provided data regarding the conventional ultrasound for the differentiation between benign and malignant salivary gland tumors. The pooled sensitivity, specificity, and DOR were 0.62 (95%CI, 0.50–0.73), 0.93 (95%CI, 0.90–0.96), and 25.07 (95%CI, 4.28–146.65), respectively. The meta-regression and subgroup analyses found that assessment methods were associated with significant heterogeneity, and quantitative or semiquantitative elastosonography performed better than the qualitative one.

Conclusions

Elastosonography showed a limited value for diagnosing malignant salivary gland tumors; it could be considered as a supplementary diagnostic technology to conventional ultrasound, and quantitative or semiquantitative elastosonography was superior to the qualitative one.

A nomogram based on clinical information, conventional ultrasound and radiomics improves prediction of malignant parotid gland lesions

Although conventional ultrasound (CUS) allows for clear detection of parotid gland lesions (PGLs), it fails to accurately provide benign-malignant differentiation due to overlapping morphological features. Radiomics is capable of processing large-quantity volume of data hidden in CUS image undiscovered by naked eyes. The aim was to explore the potential of CUS-based radiomics score (Rad-score) in distinguishing benign (BPGLs) and malignant PGLs (MPGLs). A consecutive of 281 PGLs (197 in training set and 84 in test set) with definite pathological confirmation was retrospectively enrolled. 1465 radiomics features were extracted from CUS images and Rad-score was constructed by using Least Absolute Shrinkage and Selection Operator (LASSO) algorithm. Different nomogram models, including clinic-radiomics (Clin + Rad-score), CUS-clinic (CUS + Clin) and combined CUS-clinic-radiomics (CUS + Clin + Rad-score), were built using logistic regression. The diagnostic performance of different models were calculated and compared by area under receiver operating curve (AUC) and corresponding sensitivity and specificity. Finally, 26 radiomics features were independent signatures for predicting MPGLs, with MPGLs having higher Rad-scores in both cohorts (both P < 0.05). In the test population, CUS + Clin + Rad-score obtained an excellent diagnostic result, with significantly higher AUC value (AUC = 0.91) when compared to that of CUS + Clin (AUC = 0.84) and Clin + Rad-score (AUC = 0.74), respectively (both P < 0.05). In addition, the sensitivity of this combined model was higher than that of single Rad-score model (100.00% vs. 71.43%, P = 0.031) without compromising the specificity value (82.86% vs. 88.57%, P = 0.334). The calibration curve and decision curve analysis also indicated the clinical effectiveness of the proposed combined nomogram. The combined CUS-clinic-radiomics model may help improve the discrimination of BPGLs from MPGLs.

Can Ultrasound in Combination with Virtual Touch Imaging Quantification Predict the Dignity of a Parotid Tumor?

Pre-operative evaluation of a parotid gland tumor is crucial in guiding treatment. This study evaluates the diagnostic performance of B-mode ultrasound in combination with Virtual Touch imaging quantification (VTIQ) in the assessment of parotid lesions. A prospective study of 268 patients with parotid lesions was conducted. Pre-operative ultrasound findings and VTIQ data were compared against histologic results. Ill-defined margins on ultrasound were associated with a significantly higher risk of malignancy (odds ratio [OR] = 1224.0, 95 % confidence interval [CI]: 151.8-9872.7). Faster mean shear waves on VTIQ (OR = 1.81, 95% CI: 1.47-2.23, per 1 m/s increase) and an area with shear wave velocity >6.0 m/s involving >70 % of the lesion (OR = 19.80, 95 % CI: 6.22-63.07) were associated with higher risk of malignancy. Addition of VTIQ to routine pre-operative B-mode ultrasound can provide supplemental information on the dignity of a parotid tumor, allowing for peri-operative procedural optimization.

The current value of quantitative shear wave sonoelastography in parotid gland tumors

Background

The preoperative differentiation between salivary gland tumor entities using computed tomography, magnetic resonance imaging (MRI) and ultrasound (US) is still limited. Biopsies are often regarded as indispensable for properly characterizing these various lesions. The aim of this study was to analyze the value of acoustic radiation force impulse (ARFI) sonoelastography as an US differentiation tool when examining parotid gland (PG) lesions.

Methods

We included 104 patients with PG masses in this study, employing two different US devices using quantitative ARFI-sonoelastography (Siemens Acuson-S3000, n=59; Siemens Acuson-Sequoia, n=45). The ability of sonoelastographic measurements to differentiate between different neoplasms was compared and analyzed for both US machines.

Results

Quantitative shear wave sonoelastography is limited in its ability to reliably differentiate between tumor entities of the PG as a stand-alone parameter. Measurement results were unsystematically distributed and not transferable between the two US devices. A significant differentiation of benign and malignant lesions was not possible with either US machine (S3000: P=0.770, Sequoia: P=0.382). A differentiation between pleomorphic adenomas (PA) and Warthin tumors was only possible with the Acuson S3000 system (P=0.001, Spearman-Rho =0.492, sensitivity 73.9%, specificity 65.0%).

Conclusions

A reliable identification and differentiation of PG tumors as well as clinical treatment decisions cannot be made with the sole use of ARFI-sonoelastography. The results emphasize the device-dependence and high error-proneness of this US technique when examining lesions of the PG.

Evaluation of benign parotid gland tumors with superb microvascular imaging and shear wave elastography

Aim of the study: This study aimed to examine the role of superb microvascular imaging and shear wave elastography for the pre-surgical evaluation of common parotid tumors. Material and methods: This single-center prospective study included 37 patients with parotid gland lesions. After institutional review board approval, grayscale, shear wave elastography and superb microvascular imaging ultrasound examinations were performed prior to biopsy or operation. The diagnosis of the lesions was based on cytological/pathological evaluation after the ultrasound examinations. Pleomorphic adenomas and Warthin tumors were compared using the Mann–Whitney U test. A receiver operating characteristic curve analysis was performed to obtain a cut-off value. A multivariate regression analysis was carried out. Results: The mean age of the patients (11 female, 26 male) was 48.2 ± 18. The shear wave elastography parameters of the lesions were not significantly different between pleomorphic adenomas and Warthin tumors, while the vascular index obtained by using superb microvascular imaging was significantly different (p = 0.012). The mean vascular index was 2.9 ± 3.1 in pleomorphic adenomas, and 9.5 ± 9.5 in Warthin tumors. A cut-off value of 4.05 for the vascular index discriminated pleomorphic adenoma and Warthin tumors with 68% sensitivity and 72% specificity (the area under the curve was 0.768). Conclusion: Superb microvascular imaging is a novel ultrasound imaging technique which is useful for the discrimination of pleomorphic adenomas and Warthin tumors.

Narrative review of multiparametric ultrasound in parotid gland evaluation

Disorders affecting parotid gland represent a heterogeneous group comprising congenital, inflammatory and neoplastic diseases which show a focal or diffuse pattern of appearance. The differentiation of neoplastic from non-neoplastic conditions of parotid glands is pivotal for the diagnostic imaging. Frequently there is evidence of overlapping between the clinical and the imaging appearance of the various pathologies. The parotid gland is also often object of study with the combination of different techniques [ultrasound-computed tomography-magnetic resonance imaging (US-CT-MRI), ex.]. Compared to other dominant methods of medical imaging, US has several advantages providing images in real-time at lower cost, and without harmful use of ionizing radiation and of contrast enhancement. B-mode US, and the microvascular pattern color Doppler are usually used as first step evaluation of parotid lesions. Elastography and contrast-enhanced US (CEUS) has opened further possible perspectives to improve the differentiation between benign and malignant parotid lesions. The characterization of the parotid tumors plays a crucial role for their treatment planning and for the prediction of possible surgical complications. We present, here an updated review of the most recurrent pathologies of parotid gland focusing on the diagnostic power of multiparametric US including CEUS and ultrasound elastography (USE); limitations, advantages and the main key-points will be presented.

Multimodal Ultrasound Including Virtual Touch Imaging Quantification for Differentiating Cervical Lymph Nodes

Defining the entity of cervical lymph nodes (LNs) is essential for the diagnosis and staging of head and neck malignancies. Virtual Touch imaging quantification (VTIQ) is a relatively new method of elastography that measures tissue stiffness quantitatively. A prospective study was conducted that included 108 patients (57 benign and 51 metastatic lymph nodes [MLNs]). Shear wave velocities (SWVs) were analyzed using VTIQ and were compared with the histopathological results. Both maximum and minimum SWVs within the LNs significantly differed between benign masses and MLNs (p < 0.001). Percentage areas of the node with SWVs >6 m/s and <3.5 m/s differed significantly (p < 0.001). Intralesional areas with SWVs ≤3.5 m/s of 0-29% (odds ratio: 93.7) and 30%-69% (odds ratio: 46.3) were predictive of malignant LNs as well as ill-defined tumor (odds ratio: 5.2). VTIQ can provide more information on the entity of cervical LNs.

Accuracy of transvaginal sonoelastography for differential diagnosis between malignant and benign cervical lesions: A systematic review and meta-analysis

BACKGROUND

To evaluate the performance of transvaginal sonoelastography (TVSE) for differential diagnosis between malignant and benign cervical lesions using a meta-analysis.

METHODS

An independent literature search was conducted on the English medical database, including PubMed, Embase and Medline, Cochrane Library, Web of Science, and OVID. The diagnostic accuracy of TVSE was compared with that of histopathology, which is the gold reference standard for diagnosis. The accuracy of TVSE was assessed by calculating the pooled sensitivity, specificity, diagnostic odds ratio, and area under the curve (AUC). The imaging mechanisms, assessment methods, and QUADAS scores were assessed with a meta-regression analysis. A Deeks funnel plot was performed for evaluating publication bias.

RESULTS

Six eligible studies reported a total sample of 615 cervical lesions (415 cancers, 200 benign lesions). TVSE showed a pooled diagnostic odds ratio of 21.42 (95% CI 13.65-33.61), sensitivity of 0.87 (95% CI 0.84-0.90), specificity of 0.79 (95% CI 0.72-0.84), and an AUC of 0.892 (Q* = 0.822). The results of the meta-regression analysis showed that the imaging mechanism (P = .253), the assessment method (P = .279), or QUADAS score (P = .205) did not affect the study heterogeneity.

CONCLUSION

TVSE has a relatively high and satisfactory value for differential diagnosis between malignant and benign cervical lesions. The diagnostic performance of strain elastography and shear wave elastography were similar and good. However, to accommodate heterogeneity and publication bias, high-quality studies are required to further comparative effectiveness analyses to verify the efficacy of ultrasound detection.

A Preliminary Study of CT Texture Analysis for Characterizing Epithelial Tumors of the Parotid Gland

Objective

The aim of this study was to explore and validate the diagnostic performance of whole-volume CT texture features in differentiating the common benign and malignant epithelial tumors of the parotid gland.

Materials and Methods

Contrast-enhanced CT images of 83 patients with common benign and malignant epithelial tumors of the parotid gland confirmed by histopathology were retrospectively analyzed, including 50 patients with pleomorphic adenoma (PA) and 33 patients with malignant epithelial tumors. Quantitative texture features of tumors were extracted from CT images of arterial phase. The diagnostic performance of texture features was evaluated via receiver operating characteristic (ROC) curve and area under ROC curve (AUC). The specificity and sensitivity were respectively discussed by the maximum Youden’s index.

Results

All the texture features were subject to normal distribution and homoscedasticity. Energy, mean, correlation, and sum entropy of epithelial malignancy group were significantly higher than those of PA group (P<0.05). There were no statistically significant differences between PA group and epithelial malignancy group in uniformity, entropy, skewness, kurtosis, contrast, and difference entropy (P>0.05). The AUC of each texture feature and joint diagnostic model was 0.887 (energy), 0.734 (mean), 0.739 (correlation), 0.623 (sum entropy), 0.888 (energy-mean), 0.883 (energy-correlation), 0.784 (mean-correlation). The diagnostic efficiency of energy-mean was the best. Based on the maximum Youden’s index, the specificity of energy-correlation was the highest (97%) and the sensitivity of energy was the highest (97%).

Conclusion

Energy, mean, correlation, and sum entropy can be the effective quantitative texture features to differentiate the benign and malignant epithelial tumors of the parotid gland. With higher AUC, energy and energy-mean are superior to other indexes or joint diagnostic models in differentiating the benign and malignant epithelial tumors of the parotid gland. CT texture analysis can be used as a noninvasive and valuable means of preoperative assessment of parotid epithelial tumors without additional cost to the patients.

The Role of Real-Time Elastography in the Differential Diagnosis of Salivary Gland Tumors

OBJECTIVES

The aim of the study was to scrutinize the value of qualitative elastography in the diagnosis of salivary gland masses.

METHODS

Sixty patients were enrolled in this prospective study. Patients aged between 1 and 91 years (mean age, 48.8 ± 20.48) with a salivary gland mass were studied with real-time elastography. All patients were examined by 1 examiner, blinded to all relevant data. On elastography, masses were scored into 4 types according to their stiffness compared to normal tissue. Scores of 3 and 4 were accepted as signs of malignancy. Sensitivity, specificity, and positive and negative predictive value were calculated for elastography in verifying malignancy.

RESULTS

Forty-two percent of the masses were located in the parotid, and the rest in submandibular gland. The diameter of the lesions varied between 12 and 60 mm (mean, 24.36 ± 11.98 mm). Forty-four masses were benign (73%), and among them the majority were inflammatory lesions (31 of 60; 51.7%). There were 16 malignant lesions (27%). On elastography, not only all malignant lesions but 15 benign lesions were scored as 3 to 4. All masses scored as 1 to 2 were benign. Sensitivity was 100%; specificity, 66%; positive predictive value, 52%; and negative predictive value, 100%. When only Score 4 lesions were accepted as malignant, these values became 75%, 77%, 55%, and 90%, respectively.

CONCLUSIONS

Elastography alone cannot be used to discriminate malignant from benign in the evaluation of salivary gland lesions. However, with its high negative predictive value, it may be used as an adjunct tool to increase the diagnostic value of ultrasonography.

Two case reports of synchronous unilateral pleomorphic adenoma and cystadenolymphoma of the parotid gland with literature review

Background: Synchronous unilateral tumors in the parotid glands account for less than 5-10% of all salivary gland neoplasms. Mostly these are cystadenolymphomas, but tumors of different histological types can be found as well. In these cases it is often pleomorphic adenoma in combination with cystadenolymphoma. Ultrasound is the first choice imaging modality. Case report: We present two patients with two simultaneous tumors in a unilateral parotid gland. In each case, B-mode ultrasound showed two hypoechoic masses, one of which was predominantly cystic. The subsequent use of Virtual Touch Imaging Quantification (VTIQ) showed tumors of elastic tissue. After a parotidectomy, both cases were diagnosed with pleomorphic adenoma combined with cystadenolymphoma. Conclusion: The combination of B-mode ultrasound and VTIQ is an important diagnostic modality and may improve diagnostic accuracy to differentiate between benign and malignant lesions. Every clinician should be aware of the co-existence of different histological types of tumors in unilateral salivary glands.

Background: Synchronous unilateral tumors in the parotid glands account for less than 5–10% of all salivary gland neoplasms. Mostly these are cystadenolymphomas, but tumors of different histological types can be found as well. In these cases it is often pleomorphic adenoma in combination with cystadenolymphoma. Ultrasound is the first choice imaging modality. Case report: We present two patients with two simultaneous tumors in a unilateral parotid gland. In each case, B-mode ultrasound showed two hypoechoic masses, one of which was predominantly cystic. The subsequent use of Virtual Touch Imaging Quantification (VTIQ) showed tumors of elastic tissue. After a parotidectomy, both cases were diagnosed with pleomorphic adenoma combined with cystadenolymphoma. Conclusion: The combination of B-mode ultrasound and VTIQ is an important diagnostic modality and may improve diagnostic accuracy to differentiate between benign and malignant lesions. Every clinician should be aware of the co-existence of different histological types of tumors in unilateral salivary glands.

Incidental Findings in TMJ Imaging

For years, the conventional imaging modalities are generally used in dental practice routine. They provide precious information about dentomaxillofacial region; they also have some limitations such as superimpositions, magnifications, distortions, and low-image quality. Because of these limitations, some pathologies, calcifications, and anatomical variations may be missed. Any findings on a radiographic image which are not related to the research areas of interest could be a description of “incidental findings.” Calcifications are one of these incidental findings. They are asymptomatic and also common in TMJ images. Although most of the calcifications require no treatment, correct identification will reduce further diagnostic assessments. Incidental findings on TMJ images were rare, while examining images for temporomandibular disorders and associated issues, it is important not only to examine the TMJ structures but also to look at the nearby anatomical features to check for evidence of incidental findings pathologies that may have mimicked signs and symptoms of TMJ disorders.

Sonoelastography for differential diagnosis between malignant and benign parotid lesions: a meta-analysis

Objectives

To assess the performance of sonoelastography for differential diagnosis between malignant and benign parotid lesions using a meta-analysis.

Methods

An independent literature search of English medical databases, such as PubMed, Embase and Medline (Embase.com), Web of Science, Cochrane Library and Ovid was performed. The diagnostic accuracy of sonoelastography was compared with that of histopathology and/or cytology, which was used as reference standard. The pooled sensitivity, specificity, diagnostic odds ratio (DOR) and area under the curve (AUC) were calculated to evaluate the accuracy of sonoelastography. A meta-regression analysis evaluating imaging mechanisms, shear wave elastography techniques, assessment methods and QUADAS scores was performed.

Results

Ten eligible studies that included a total sample of 711 patients with 725 parotid lesions were included. Sonoelastography showed a pooled sensitivity of 0.67 (95% CI 0.59–0.74), specificity of 0.64 (95% CI 0.60–0.68), DOR of 8.00 (95% CI 2.96–21.63) and an AUC of 0.77. The results of the meta-regression analysis revealed that no heterogeneity was due to the imaging mechanism (p = 0.119), shear wave elastography technique (p = 0.473) or QUADAS score (p = 0.462). However, the assessment method was a significant factor that affected the study heterogeneity (p = 0.035). According to the subgroup analysis, quantitative and semiquantitative methods performed better than qualitative ones.

Conclusion

Overall, sonoelastography has a limited value for differential diagnosis between malignant and benign parotid lesions. Quantitative and semiquantitative methods perform better than qualitative ones.

Key Points

• Overall, sonoelastography has a limited value for differential diagnosis between malignant and benign parotid lesions.

• Quantitative and semiquantitative assessment methods perform better than qualitative ones.

• Semiquantitative and quantitative methods are automatically calculated by an ultrasound machine and are thus less operator-dependent.

Diagnostic accuracy of sonoelastography in different diseases

The objective of this study was to evaluate the diagnostic accuracy of sonoelastography in patients of primary and secondary health care settings. Google scholar, PubMed, Medline, Medscape, Wikipedia and NCBI were searched in October 2017 for all original studies and review articles to identify the relevant material. Two reviewers independently selected articles for evaluation of the diagnostic accuracy of sonoelastography in different diseases based on titles and abstracts retrieved by the literature search. The accuracy of sonoelastography in different diseases was used as the index text, while B-mode sonography, micro pure imaging, surgery and histological findings were used as reference texts. Superficial lymph nodes, neck nodules, malignancy in thyroid nodules, benign and malignant cervical lymph nodes, thyroid nodules, prostate carcinoma, benign and malignant breast abnormalities, liver diseases, parotid and salivary gland masses, pancreatic masses, musculoskeletal diseases and renal disorders were target conditions. The data extracted by the two reviewers concerning selected study characteristics and results were presented in tables and figures. In total, 46 studies were found for breast masses, lymph nodes, prostate carcinoma, liver diseases, salivary and parotid gland diseases, pancreatic masses, musculoskeletal diseases and renal diseases, and the overall sensitivity of sonoelastography in diagnosing all these diseases was 83.14% while specificity was 81.41%. This literature review demonstrates that sonoelastography is characterized by high sensitivity and specificity in diagnosing different disorders of the body.

Assessment of the Pancreas with Strain Elastography in Healthy Children: Correlates and Clinical Implications

Background

To determine strain index (SI) values at various locations in the pancreas and to investigate the relationship between age, gender, body weight, height, body mass index (BMI), and elasticity values of the pancreas in healthy children.

Material/Methods

This cross-sectional trial was performed in 147 healthy children who underwent transabdominal ultrasonography for strain elastography of the pancreas. A convex, 3.5–5-MHz probe was used to obtain the images. Baseline descriptive data including age (months), body weight (kg), height (cm), and BMI (kg/m2) were noted. Strain index values were calculated for the head, body, and tail of the pancreas, and a mean value was obtained. The relationship between demographic variables and SI values was assessed. Correlation between variables with normal distribution was evaluated with Pearson’s correlation coefficient and Spearman’s rho.

Results

The average SI values in girls and boys were 1.30±0.34 and 1.32±0.22, respectively. There was no significant difference between SI values measured in the head, trunk, and tail of the pancreas (p=0.594). The average SI value did not differ between girls and boys (p=0.751). Correlation analysis revealed that SI was positively associated with age (p=0.005), body weight (p=0.004), height (p=0.003), and BMI (p=0.005).

Conclusions

This study determined normal elasticity values of the pancreas in healthy children. SI values of pancreas change with age, body weight, height, and BMI in the pediatric population. Information obtained from healthy children can serve as a baseline against which pancreatic diseases can be examined.

Differential Diagnosis of Parotid Gland Tumors: Role of Shear Wave Elastography

AIM

To create a predictive score for the discrimination between benign and malignant parotid tumors using elastographic parameters and to compare its sensitivity and specificity with standard ultrasound.

METHODS

A total of 124 patients with parotid gland lesions for whom surgery was planned were examined using conventional ultrasound, Doppler examination, and shear wave elastography. Results of the examinations were compared with those ones of histology.

RESULTS

There were 96 benign and 28 malignant lesions in our cohort. Blurred tumor margin alone proved to be an excellent predictor of malignancy with the sensitivity of 79% and specificity of 97%. Enlarged cervical lymph nodes, tumor vascularisation, microcalcifications presence, homogeneous echogenicity, and bilateral occurrence also discriminated between benign and malignant tumors. However, their inclusion in a predictive model did not improve its performance. Elastographic parameters (the stiffness maxima and minima ratio being the best) also exhibited significant differences between benign and malignant tumors, but again, their inclusion did not significantly improve the predictive power of the blurred margin classifier.

CONCLUSION

Even though elastography satisfactorily distinguishes benign from malignant lesions on its own, it hardly provides any additional value in evaluation of biological character of parotid gland tumors when used as an adjunct to regular ultrasound examination.

Benign Parotid Tumors

This article reviews the epidemiology, embryology, risk factors, clinical presentation, diagnostic work-up, and basic management principles for the more common benign parotid neoplasms. The various histopathologies are also discussed and summarized.

Initial Experience With Ultrasound Elastography for Diagnosis of Major Salivary Gland Lesions

OBJECTIVES

The aim of this study was to evaluate the usefulness of ultrasound elastography, including conventional strain elastography, acoustic radiation force impulse (ARFI)-induced strain elastography, and point shear wave elastography (SWE) for diagnosis of major salivary gland lesions.

METHODS

Forty major salivary gland lesions underwent conventional sonography, conventional strain elastography, ARFI strain elastography, and point SWE before surgery or biopsy. The diagnostic performances of the sonographic and elastographic techniques were assessed with reference to histopathologic results.

RESULTS

There were 32 benign (7 Warthin tumors, 17 pleomorphic adenomas, and 8 other benign lesions) and 8 malignant (1 squamous carcinoma, 2 metastases, 2 mucoepidermoid carcinomas, 1 anaplastic carcinoma, and 2 malignant lymphomas) major salivary gland lesions on pathologic analysis. No conventional sonographic features or conventional strain elastographic scores were found to be associated with malignancy (all P > .05). The ARFI strain elastographic scores between benign and malignant lesions were statistically different (P = .032) and an ARFI strain elastographic score of 4 or greater was highly predictive of malignancy (P= .025). An ARFI strain elastographic score of greater than 3 achieved specificity of 81.3% (26 of 32) and sensitivity of 62.5% (5 of 8) in differentiating benign from malignant lesions. The shear wave velocity on point SWE did not show a significant difference in distinguishing between malignant and benign lesions (6.07 versus 4.43 m/s; P > .05). However, Warthin tumors had a trend to show lower shear wave velocities compared with pleomorphic adenomas (2.84 versus 5.27 m/s; P = .024).

CONCLUSIONS

Acoustic radiation force impulse strain elastography may be potentially useful for diagnosing major salivary gland lesions, whereas conventional strain elastography and point SWE are not helpful.

Effect of liposomal local therapy on salivary glands in acoustic radiation force impulse imaging in Sjögren's syndrome

The purpose of this study was to evaluate the utility of acoustic radiation force impulse (ARFI) imaging as a monitoring tool for the effect of a liposomal local therapy in patients with dry mouth symptoms due to primary Sjögren's syndrome (pSS). Fifty patients with pSS, diagnosed according to the American-European Consensus Group (AECG) criteria, were included. Clinical data were collected, and sonographic examination including ARFI imaging of the parotid and submandibular glands was performed. Subjective symptoms were evaluated via visual analogue scales (VAS), and the unstimulated whole salivary flow was measured. After a two-month period of liposomal local therapy, sonographic examination was repeated and both subjective and objective symptoms were re-evaluated. Before local treatment, the mean ARFI value of parotid glands was 2.96 m/s (SD 0.97). Mean ARFI value of the submandibular glands was 2.09 m/s (SD 0.71). After the two-month treatment period, a significant decline of ARFI values in the parotid glands to a value of 2.34 m/s (SD 0.70, p < 0.001) could be observed. The submandibular glands did not show any significant change. Further, a significant reduction of the subjective sensation of dry mouth symptoms could be observed (p = 0.0001). With the application of ARFI imaging, a decline in parotid gland stiffness could be observed in patients with primary Sjögren's Syndrome accompanied by a significant improvement of the subjective sensation of dry mouth symptoms. The seromucous submandibular glands did not show any changes compared to the serous parotid glands.

Evaluation of Parotid Glands With Real-time Ultrasound Elastography in Children

OBJECTIVES

The aim of this study was to determine the strain index for parotid glands in children by using ultrasound elastography.

METHODS

In this prospective study, apparently healthy children were referred from the ear-nose-throat clinic to the radiology clinic for elastographic examinations. Conventional sonographic and elastographic examinations of the parotid glands were performed. A linear 5-12-MHz transducer was used to obtain the images.

RESULTS

A total of 54 children were enrolled in this prospective study. The normal mean strain index value ± SD for the parotid glands was 1.24 ± 0.67 (range, 0.29-1.39) regardless of sex. The mean age of girls was 7.42 ± 2.94 years (range, 3-14 years), and the age of boys was 8.50 ± 3.46 years (range, 4-16 years). The strain index values for the parotid glands in boys was 1.25 ± 0.76, and in girls it was 1.22 ± 0.55. There was no statistically significant difference in the strain index values between girls and boys (P= .986). There was no correlation between the strain index and age (r = 0.026) or body mass index (r = 0.066).

CONCLUSIONS

This study determined the mean strain index values for apparently healthy children. Such information can serve as a baseline from which pathologic parotid diseases can be diagnosed with ultrasound elastography in combination with other sonographic criteria.

Applicability of shear wave elastography of the major salivary glands: values in healthy patients and effects of gender, smoking and pre-compression

Our aim in this study was to determine normal shear wave elastography (SWE) values for the parenchyma of the major salivary glands and to evaluate the influences of gender, smoking, side and type of gland and varying amounts of ultrasound probe pressure on SWE values. Twenty-five consecutive healthy patients were examined with ultrasound. SWE velocities were measured with acoustic radiation force imaging in the hilum and central region of both glands with "normal" and very low pressure. Mean SWE velocities were 1.854 m/s for the parotid gland and 1.932 m/s for the submandibular gland. No statistically significant differences were detected between males and females, smokers and non-smokers, parotid and submandibular gland and left and right sides. Greater pre-compression with the ultrasound probe resulted in a statistically significant increase in the SWE values of both salivary glands (p < 0.000). The degree of pre-compression by the ultrasound transducer should be standardized, so that the reliability and reproducibility of this innovative method can be improved.

Unexpected Detection of Parotid Gland Malignancy during Primary Extracapsular Dissection

Objective

To evaluate the oncologic and functional outcome in cases in which a false preoperative working hypothesis “benign parotid tumor” led to a primary extracapsular dissection being performed rather than a traditional, more radical surgical modality.

Study Design

Case series with chart review.

Setting

Academic tertiary referral center.

Subjects and Methods

The records of all patients treated for malignant tumors of the parotid gland between 2006 and 2012 were retrospectively studied. Patients were excluded from our study sample for insufficient data or if their histories indicated manifestation of malignant tumors without primary parotid origin (squamous cell carcinomas, lymphomas, melanomas), revision surgery, as well as concomitant or past malignant tumors. Consequently, a total of 29 patients with 30 primary malignant tumors of the parotid gland formed our study sample (14 men, 15 women; male:female ratio, 0.93:1; mean age, 55.4 years; range, 14-85 years).

Results

Of 30 cases, 22 had low-grade tumors. Further tumor cells were detected in only the histology specimens of the parotid in 3 of the 25 cases treated subsequently with completion parotidectomy. Five patients received adjuvant radiation. Five-year disease-specific survival was 100%; local disease control was 96.6%. Of 30 cases, 28 had House-Brackmann I after tumor treatment; the other 2 cases had a slight paralysis (House-Brackmann II).

Conclusion

Beginning with the “false” working hypothesis and performing an extracapsular dissection in unsuspected cases seems to have no adverse impact on patients’ survival and postoperative quality of life in cases in which definitive histology reveals malignancy.

Intraparotid facial nerve schwannoma: A case report

Facial nerve schwannoma occurring within the parotid gland is a rare tumour. We report a case of schwannoma within the parotid gland in a young female patient, who underwent ultrasound and magnetic resonance imaging (MRI) and subsequent surgical excision of the lesion. The lesion showed hyperintensity on T2-weighted and diffusion-weighted MRI. There was no adjacent lymphadenopathy. Although hyperintensity on diffusion-weighted MRI could suggest malignant tumours, the characteristic "string sign" provided the clue for the diagnosis of schwannoma.

Accuracy of diagnosis of salivary gland tumors with the use of ultrasonography, computed tomography, and magnetic resonance imaging: a meta-analysis

OBJECTIVE

To compare ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) for clinical differential diagnosis in patients with salivary gland tumor (SGT).

STUDY DESIGN

Six databases were used to search the literature published between 1982 and 2013. Histologic diagnosis was required as standard diagnosis. Pooled estimate for sensitivity, specificity, summary receiver-operating characteristic curve (SROC) and area under curve (AUC) were calculated and compared using STATA and Meta-Disc statistical software.

RESULTS

Nineteen articles were included. Pooled sensitivity for US, CT, and MRI was 0.629 (95% confidence interval [CI] 0.52-0.73), 0.830 (95% CI 0.74-0.90), and 0.807 (95% CI 0.73-0.87), respectively; pooled specificity for US, CT, and MRI was 0.920 (95% CI 0.89-0.94), 0.851 (95% CI 0.79-0.90), and 0.886 (95% CI 0.85-0.92), respectively. The AUC under SROC for US, CT, and MRI was 0.934 ± 0.058, 0.912 ± 0.889, and 0.903 ± 0.045, respectively.

CONCLUSIONS

CT is recommended, as it is an effective imaging tool for differential diagnosis in patients with primary SGT, and MRI is suggested for differential diagnosis between benign and malignant GSTs because of its highest sensitivity and specificity.

The role of elastosonography in the differentiation of parotid gland lesions: report of three cases and review of the literature

Background

The parotid gland is the mostly affected site among major salivary gland tumors in up to 85% of cases. Preoperative knowledge of the tumour nature is crucial since it influences the surgical procedure and patient’s morbidity, especially the risk of facial nerve palsy. Ultrasonography is commonly used as the first line imaging modality for the salivary gland lesions. A pitfall is that the histologic pleomorphism often reflects an imaging pleomorphism.

Case Report

Herein we aimed to present the role of elastosonography in three parotid lesions: a case of benign pleomorphic adenoma, a Wharthin’s tumour and a malignant parotid tumour.

Conclusions

Our findings show that malignant parotid lesion was the stiffest lesion according to elastosonography. Wharthin’s tumour demonstrated soft elastosonographic features. The pleomorphic adenoma was also interpreted as stiff by elastosonography suggesting that the elastosonographic features of pleomorphic adenoma may resemble those of malignant lesions limiting the utility of the technique.

Shear wave elastography: a new noninvasive tool to assess the intensity of fibrosis of irradiated salivary glands in head and neck cancer patients

The aim of the study was to assess salivary gland parenchyma by means of sonoelastography in patients irradiated for head and neck squamous cell carcinoma (HNSCC). The studied group consisted of 52 patients after radiotherapy (RT) and 54 healthy volunteers. All of the former were treated for advanced larynx (40), oropharynx (9), or maxilla (3) squamous cancers and suffered from chronic dryness. Ultrasonography (US) and elastography (ES) were performed, as well as an assessment of the amount of saliva and Common Terminology Criteria for Adverse Events (CTCAE) scale. There was a statistical difference between ES values in the RT group and in the controls for parotid glands (41.7 kPa versus 26.03 kPa, P = 0.0018) and for submandibular glands (37.6 kPa versus 22.4 kPa; P = 0.005). There was a significant correlation between the CTCAE scores and objective saliva amount (P = 0.0005), and the median amount of saliva in the examined group was lower than in the reference group (1.86 g versus 2.75 g, P = 0.0006). In conclusion sonoelastography adds a new parameter to ultrasonography in “one touch examination” and may be a useful tool for major salivary gland evaluation during the radiotherapy course and follow-up period.

Relative proportions of stromal to cellular components of pleomorphic adenomas: determination with shear wave elastography

OBJECTIVES

The purpose of this study was to evaluate whether the relative proportions of stromal to cellular components of pleomorphic adenomas have an effect on the shear elastic modulus determined by shear wave elastography (SWE).

METHODS

This study was approved by the Ethics Committee of our institution and performed between September 2011 and December 2012. Thirty-five patients who underwent surgery for a parotid mass were included in the study. The maximum shear elastic modulus of the mass was measured by SWE. Pleomorphic adenomas were histopathologically subdivided into stroma-poor, intermediate-stroma, and stroma-rich tumors based on the relative proportion of stromal to cellular components.

RESULTS

The maximum shear elastic modulus values of the pleomorphic adenomas ranged from 12.6 to 291.9 kPa (mean ± SD, 120.9 ± 92.8 kPa). The Friedman test revealed a statistically significant relationship between the stromal amount and maximum shear elastic modulus (P < .001). Stroma-poor adenomas (mean, 32.3 ± 27.7 kPa; range, 12.6-81.1 kPa) were softer on SWE than stroma-rich adenomas (mean, 174.1 ± 48.4 kPa; range, 92.7-217.2 kPa; P = .009). No such significant difference was detected between stroma-poor and intermediate-stroma tumors (mean, 146.3 ± 106.1 kPa; range, 19.1-291.9 kPa; P = .062) or between intermediate-stroma and stroma-rich tumors (P = .465).

CONCLUSIONS

Shear wave elastography depicts pleomorphic adenomas with a variable appearance, which is due to the relative proportions of stromal to cellular contents in the tumors.

Effects of compression force on elasticity index and elasticity ratio in ultrasound elastography

OBJECTIVES

The purpose of this study was to investigate the relationship between compression force and hardness values in ultrasound elastography.

METHODS

Ultrasound elastography was performed using an elastography phantom, comprising inclusions with different elasticities and echogenicities. The compression force was set to approximately 100 gw (light force) and approximately 500 gw (heavy force). The elasticity index (EI) of the inclusion was measured. The EI was a relative hardness value of a structure within an elastographic image. Similarly, the EI of the background was measured as a reference. The elasticity ratio (ER) was calculated as the EI of the inclusion divided by the EI of the reference.

RESULTS

The hardness of the phantom could be discerned with both the EI and ER, regardless of the compression force. The EI and ER with heavy force tended to be higher than those with light force, but the difference was not significant. A strong correlation was observed between the EI and ER of soft structures, whereas the correlation between the EI and ER of hard structures was weak, and the ER values varied widely.

CONCLUSIONS

The EI offers potential as a good indicator for assessing the hardness.

[Current treatment strategies for papillary thyroid microcarcinoma]

The increase in the incidence of thyroid cancer is accompanied by a mortality rate that is stable or perhaps even slightly decreasing. This phenomenon is due to the increased frequency of papillary microcarcinomas (thyroid tumors with a diameter of less than 1 cm), which is presumably attributable to the improved diagnosis enabled by high resolution ultrasound and fine needle aspiration cytology. The American and European Thyroid Associations have recently published new guidelines for the diagnosis and therapy of differentiated thyroid tumors. These guidelines are aimed at minimizing the diagnostic and therapeutic procedures without reducing their effectiveness. This goal is particularly important for papillary thyroid microcarcinoma patients, who have an excellent prognosis and almost normal life expectancy. This article summarizes the history of thyroid surgery and introduces papillary thyroid microcarcinoma--an important topic in modern thyroid oncology. Current methods for diagnosis, treatment and follow-up care of this disease are discussed.