Evaluation of real-time qualitative sonoelastography of focal lesions in the parotid and submandibular glands: applications and limitations

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.

Efficacy of ultrasound shear wave elastography in the diagnosis of salivary gland tumors

PURPOSE

Diagnostic accuracy of fine-needle aspiration cytology (FNAC) as the ability to discriminate between the target condition and health in the evaluation of salivary gland tumors is not perfected yet and false-negative results are possible. The purpose of the present study was to measure and compare the diagnostic accuracy of FNAC performed with conventional B-mode ultrasound and ultrasound with shear wave elastography (SWE) FNAC navigation.

METHODS

The investigators implemented a single-blind randomized study (sealed envelope method). The study population was composed of all patients presenting for evaluation and management of suspected benign or malignant tumors of the major salivary glands between July 2013 and December 2020. The involvement of SWE navigation was the primary predictor variable affecting FNA targeting. The method involved analysis of redistribution of SWE values within the affected gland expressed in kilopascals (kPa) and the four-point ES1 (soft tissue) to ES4 (stiff) scoring. The primary outcome variable was the success in obtaining diagnostic tissue resulting in a histologically confirmed FNAC diagnosis and coded as yes/no. Age and sex of the patients and topographical locations of lesions were covariates. Descriptive and bivariate statistics were computed and the P value was set at .05.

RESULTS

The sample included 132 subjects (male/female 59/73; mean age 54 ± 11 years; 144 tumors). SWE + Group (n = 66) consisted of patients presurgically diagnosed with salivary tumors SWE-guided FNAC and SWE- Group (n = 66) was diagnosed with tumors by conventional ultrasound-(B-mode)-guided FNAC. The SWE-guided FNAC statistically significantly reduced the incidence of false-negative results (n = 0; P = .001) and nondiagnostic cases (n = 3 SWE FNAC vs n = 7 B-mode US FNAC; P = .04). For SWE + Group, the FNAC diagnosis was confirmed by postsurgical histology in 95.5% with 91.0% sensitivity (confidence interval [CI] 0.62 to 0.97) and 84.4% specificity (CI 0.58 to 0.96). For SWE- Group, 81.8% confirmation was obtained (P = .05) with 82.3% sensitivity (CI 0.54 to 0.90) and 74.0% specificity.

CONCLUSION

SWE can increase success in obtaining diagnostic tissue when used for FNAC navigation purposes. We suggest combining both SWE and standard B-mode US methods when the FNAC procedure is performed.

Comparisons among the Ultrasonography Prediction Model, Real-Time and Shear Wave Elastography in the Evaluation of Major Salivary Gland Tumors

We aimed to validate the diagnostic accuracy of a novel sonographic scoring model and compare it with other methods in the evaluation of malignant major salivary gland tumors. We enrolled 138 patients who received neck ultrasound (US) with fine needle aspiration (FNA) and further operations or core needle biopsies for major salivary gland tumors from June 2015 to October 2021. The sonographic scoring model was presented as 2.08 × (vague boundary) + 1.75 × (regional lymphadenopathy) + 1.18 × (irregular or speculated shape) + 1.45 × (absence of posterior acoustic enhancement) + 2.4 × (calcification). We compared the diagnostic accuracy of the sonographic scoring model with shear wave elastography (SWE), real-time elastography (RTE), and US-FNA cytology for differentiating between benign and malignant lesions. The sensitivity, specificity, and accuracy were 58%, 89%, and 85% for the sonographic scoring model, 74%, 62%, and 64% for the SD of SWE with optimal cutoff value of 31.5 kPa, 69%, 70%, and 70% for the 4-point scoring system of RTE, and 74%, 93%, and 91% for US-FNA cytology, respectively. The sonographic scoring model is feasible as assistance in the evaluation of major salivary gland tumors. US-FNA cytology remains the tool of choice in diagnosing malignant salivary gland tumors.

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.

Comparative Study of Qualitative and Quantitative Analyses of Contrast-Enhanced Ultrasound and the Diagnostic Value of B-Mode and Color Doppler for Common Benign Tumors in the Parotid Gland

Purpose

To preliminarily identify three common benign parotid gland tumors: pleomorphic adenomas (PA), Warthin tumors (WT), and basal cell adenomas (BCA) by qualitative and quantitative analyses using contrast-enhanced ultrasound (CEUS).

Methods

Preoperative images of parotid gland masses were analyzed, including 129 cases of ultrasonography (US) and color Doppler sonography (CDS) and 110 cases of qualitative and quantitative CEUS. The diagnosis was confirmed by postsurgical pathology outcomes.

Results

PA presented low and heterogeneous enhancement and echo-free area, whereas most WT and BCA presented with high and relatively homogeneous enhancement. Compared with WT and BCA groups, a “slow in” pattern was more common in the PA group and a “slow out” pattern was more frequently noted in the WT group than in the PA and BCA groups. The unique features of qualitative CEUS in the PA group enable distinguishing PA from the 2 other groups. The further distinction among the groups was made based on quantitative parameters of time-intensity curves (TICs), which revealed that the mean peak intensity (PI), mean transit time (MTT), the area under the curve (AUC), and time from peak to one half (HT) exhibited significant differences. ROC analysis was next applied to determine the optimal cutoff points to predict the diagnostic tendency among the groups. When the rising slope (RS) was >2.145, the possibility of BCA was greater than WT.

Conclusions

CEUS ultrasound is of significant value in the differential diagnosis of the 3 common benign parotid gland masses.

MRI-Based radiomics nomogram for differentiation of benign and malignant lesions of the parotid gland

OBJECTIVES

Preoperative differentiation between benign parotid gland tumors (BPGT) and malignant parotid gland tumors (MPGT) is important for treatment decisions. The purpose of this study was to develop and validate an MRI-based radiomics nomogram for the preoperative differentiation of BPGT from MPGT.

METHODS

A total of 115 patients (80 in training set and 35 in external validation set) with BPGT (n = 60) or MPGT (n = 55) were enrolled. Radiomics features were extracted from T1-weighted and fat-saturated T2-weighted images. A radiomics signature model and a radiomics score (Rad-score) were constructed and calculated. A clinical-factors model was built based on demographics and MRI findings. A radiomics nomogram model combining the Rad-score and independent clinical factors was constructed using multivariate logistic regression analysis. The diagnostic performance of the three models was evaluated and validated using ROC curves on the training and validation datasets.

RESULTS

Seventeen features from MR images were used to build the radiomics signature. The radiomics nomogram incorporating the clinical factors and radiomics signature had an AUC value of 0.952 in the training set and 0.938 in the validation set. Decision curve analysis showed that the nomogram outperformed the clinical-factors model in terms of clinical usefulness.

CONCLUSIONS

The above-described radiomics nomogram performed well for differentiating BPGT from MPGT, and may help in the clinical decision-making process.

KEY POINTS

• Differential diagnosis between BPGT and MPGT is rather difficult by conventional imaging modalities. • A radiomics nomogram integrated with the radiomics signature, clinical data, and MRI features facilitates differentiation of BPGT from MPGT with improved diagnostic efficacy.

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations for practicing physicians and other healthcare providers on the management of salivary gland malignancy.

METHODS

ASCO convened an Expert Panel of medical oncology, surgical oncology, radiation oncology, neuroradiology, pathology, and patient advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2020. Outcomes of interest included survival, diagnostic accuracy, disease recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 293 relevant studies to inform the evidence base for this guideline. Six main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate radiotherapy techniques, the role of systemic therapy, and follow-up evaluations.

RECOMMENDATIONS

When possible, evidence-based recommendations were developed to address the diagnosis and appropriate preoperative evaluations for patients with a salivary gland malignancy, therapeutic procedures, and appropriate treatment options in various salivary gland histologies.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

Clinical Utility of Qualitative Elastography Using Acoustic Radiation Force Impulse for Differentiating Benign from Malignant Salivary Gland Tumors

The goal of the work described here was to evaluate the utility of acoustic radiation force impulse (ARFI) imaging, a novel elastography technique, for differentiating benign from malignant salivary gland tumors. With the use of conventional strain elastography (SE) and ARFI imaging with a four-pattern scoring system, 185 tumors were examined (163 benign/22 malignant). When a score of ≥3 was used to define malignancy, the sensitivity, specificity and accuracy were higher for ARFI imaging (77.3%, 63.8% and 65.4%, respectively) than for conventional SE (54.5%, 56.4% and 56.2%, respectively). ARFI imaging findings revealed that most (92%) Warthin tumors, but only 24% of pleomorphic adenomas, were benign (score: 1 or 2). Attenuation of acoustic push pulses made it difficult to determine the stiffness of malignant tumors in the deep parotid lobes. Thus, ARFI imaging is a useful tool for screening Warthin tumors and exhibits high sensitivity for malignant tumors of salivary glands, other than deep parotid lobe tumors.

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.

Kimura Disease: A Case Series and Systematic Review of Clinico-radiological Features

Kimura disease is a rare chronic inflammatory disorder mostly reported in males in second to third decades from south-east Asia. Head and neck is the most commonly involved region. The usual presentation is painless facial swelling with salivary gland involvement and regional lymphadenopathy. The diagnosis can be suspected on imaging but needs to be proven on histopathology. We describe three histopathology proven cases of Kimura disease and emphasize the specific clinic-radiological findings which can help in early identification of the condition and its differentiation from other diseases with similar presentation. Gray scale Ultrasound, contrast-enhanced ultrasound, and contrast-enhanced Magnetic Resonance Imaging (CE-MRI) were done in all patients and Computed Tomography (CT) was done in one. The salient imaging features were ill-defined solid mass in the subcutaneous location of the facial region which was heteroechoic on Gray scale Ultrasound, heterogeneously hyperintense on T2W MRI and without much diffusion restriction. There was involvement of salivary glands with ipsilateral cervical adenopathy. The lesion showed avid contrast enhancement on contrast-enhanced ultrasound and CE-MRI. We also present a systematic literature review of clinico-radiological features in Kimura disease in the head and neck. The articles with histopathologically proven cases and satisfactory description of imaging findings were included and we have compared the findings in our cases with published literature. In addition, we have included examples of radiological mimics of this disease. Certain imaging findings are highly suggestive and can aid in early diagnosis of Kimura disease which helps in early initiation of treatment with better patient prognosis.

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

Purpose

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

Materials and Methods

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

Results

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

Conclusion

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

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.

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.

Does acoustic radiation force elastography improve the diagnostic capability of ultrasound in the preoperative characterization of masses of the parotid gland?

OBJECTIVES:

Ultrasound is the method of choice for preoperative evaluation of tumours of the parotid glands. However, existing methods do not allow for clear differentiation between the most common benign tumours and malignant tumours. The aim of our study was to evaluate if acoustic radiation force, Virtual Touch Quantification (VTQ) elastography helps to improve the preoperative evaluation of parotid masses.

METHODS:

We investigated the parenchyma of 102 parotid glands, 14 lymph nodes of healthy volunteers and 51 tumours of the parotid gland via ultrasound, colour Doppler ultrasound and VTQ. The results were matched with histopathology and analyzed.

RESULTS:

The perfusion in pleomorphic adenoma, the most frequent benign tumour of the parotid gland, was significantly lower in comparison to malignant tumours. All tumours showed statistically significant higher perfusion in comparison to the parenchyma or the lymph nodes of the gland. Shear wave velocity of the user-defined region of interest was statistically significant more frequently an overflow value higher than 8.5 m/s in total tumours in comparison to parenchyma or lymph nodes. The different tumour types presented no significant difference in the shear wave velocity.

CONCLUSIONS:

VTQ in combination with classical ultrasound examination provides additional data useful in distinguishing between benign and malignant tumours and thus shows promise for integration into preexisting ultrasound protocols. However, despite the improvement, clear differentiation of tumours is still not possible and further investigation is recommended.

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.

Does Virtual Touch IQ elastography help to improve the preoperative diagnosis of parotid tumors: A prospective trial

BACKGROUND

It is difficult to assess tumors of the parotid gland preoperatively. However, it is essential for the surgeon to know which kind of tumor is present. Ultrasound is the method of choice, but there is still no reliable differential diagnostic tool for determining whether a tumor is malignant or benign.

OBJECTIVE

The aim of our study was to examine the value of Virtual Touch imaging quantification (VTIQ) elastograpy in distinguishing between malignant and benign tumors as well as in identifying the most common benign tumor types.

METHODS

The parenchyma of 100 parotid glands and 12 lymph nodes of healthy volunteers and 50 tumors of the parotid gland were analyzed via ultrasound, color Doppler ultrasound, and VTIQ, and the results were then compared with histopathology.

RESULTS

In comparison with benign tumors, in malignant tumors the tumor border was diffuse, the perfusion higher, and the VTIQ quality much lower. Share wave velocity of the user-defined region of interest was more frequently higher than 6.8 m/s in malignant tumors in comparison to benign tumors.

CONCLUSIONS

VTIQ in combination with ultrasound examination provides additional information for distinguishing between benign and malignant tumors and shows promise for integration into preexisting ultrasound protocols.

Importance of Sonoelastography in Assessing Non-Thyroid Neck Masses

Objective

To evaluate the feasibility and value of sonoelastography in assessing non-thyroid neck masses.

Methods

Non-thyroid neck masses requiring surgical interventions were evaluated using conventional B-mode ultrasonography (US) (size, short/long axis rate, shape, hilum, echogenity, calcification, necrosis, and peripheral edema) and sonoelastograpy (SE) with strain ratio (SR) and elasticity score (ES) before surgery. These parameters were compared with the histopathological examination.

Results

In total, 116 non-thyroid neck masses (66 lymph node, 35 parotid gland, eight submandibular gland, and seven cervical mass) of 89 patients (51 men, 38 women) with a mean age of 50.3±15.1 (19-79) years were evaluated. Thirty-seven malignant lymph nodes (23 metastatic and 14 lymphoma), seven malignant parotid tumors, two malignant submandibular tumors, 29 benign lymph nodes, 28 benign parotid lesions, and six benign submandibular lesions were evaluated. Mean SR and ES values of malignant masses were 6.3/3.2 for lymph nodes, 5.5/3.3 for the parotid gland, and 4.2/3 for the submandibular gland. Mean SR and ES values of benign lesions were 2.0/2.1 for lymph nodes, 4.4/3.2 for the parotid gland, and 3.2/3 for the submandibular gland. SR and ES were significantly higher for malignant masses compared with those for benign ones. SR was more predictive than ES in evaluating malignant lymph nodes. The area under the curve was 0.917(0.827-1.00) (p<0.05) for SR in differentiating benign-malignant lymph nodes, and the upper cut-off value was two. SR and ES were higher in the malign parotid and submandibular gland lesions than the benign ones, but the difference was not statistically significant.

Conclusion

Strain ratio value could be a useful parameter in differentiating benign-malignant lymph nodes. More studies are necessary for differentiating benign-malignant parotid and submandibular lesions using SE.

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.

Sonoelastographic Modalities in the Evaluation of Salivary Gland Characteristics in Sjögren's Syndrome

The purpose of this study was to investigate salivary tissue assessment with various sonoelastographic modalities (real-time tissue elastography, Virtual Touch imaging and quantification) in patients with Sjögren's syndrome as compared with an appropriate control group. The sonoelastographic modalities were evaluated in 50 patients with primary Sjögren's syndrome (pSS). Patients underwent high-resolution ultrasonography of the submandibular and parotid glands. Results of B-mode, real-time tissue elastography, Virtual Touch imaging-each graded with the appropriate scoring system-and Virtual Touch quantification were compared with those for 50 patients with sicca symptoms who did not fulfill the American-European consensus group criteria. In B-mode, 34 of 50 parotid glands in patients with pSS and 8 of 50 in the control group had abnormal findings (p < 0.001). Compared with 9 of 50 control patients, 38 of 50 patients with pSS had abnormal findings in submandibular gland B-mode (p < 0.001). With real-time tissue elastography, there was a trend toward higher scores for parotid glands in the pSS group (p = 0.238), whereas scores for submandibular glands in the control group were higher (p = 0.107). Virtual Touch imaging did not indicate any difference (p = 0.647 and p = 0.658). In Virtual Touch quantification, values for parotid (mean: 2.99 m/s) and submandibular glands (mean: 2.54 m/s) in the pSS group were higher than those for parotid (mean: 2.16 m/s) and submandibular (mean: 2.04 m/s) glands in the control group (p < 0.001 and p = 0.008). Glandular stiffness, measured by Virtual Touch quantification, was significantly higher in patients with Sjögreńs syndrome than in patients with sicca symptoms.

Application of DTI and ARFI imaging in differential diagnosis of parotid tumours

OBJECTIVES

To explore the utility of diffusion tensor imaging (DTI) and acoustic radiation force impulse (ARFI) imaging in the diagnosis of parotid tumours.

METHODS

51 patients with parotid tumours were examined with DTI on 3.0-T MRI and ARFI imaging on an ultrasound scanner before surgery. Values of apparent diffusion coefficient (ADC), fractional anisotropy (FA) and shear-wave velocity (SWV) were calculated and analyzed with independent samples Wilcoxon-Mann-Whitney test. Cut-off values, sensitivity and specificity were calculated with receiver-operating characteristic (ROC) curve analysis. The value of combination was calculated through parallel test for the cut-off value of ADC, FA and SWV (combination = 0 or 1); then, ROC analysis was performed with pathological results as the gold standard to calculate the sensitivity and specificity for the combination of the three parameters distinguishing benign and malignant parotid tumours. Pathological diagnosis for every patient was made post-operatively from the tumour tissue taken during operation.

RESULTS

There was a significant difference between benign and malignant tumours in the values of ADC, FA and SWV (p = 0.032, p = 0.011 and p < 0.0001); a significant difference in the values was also found between pleomorphic adenoma and malignant tumour (p = 0.0012, p < 0.0001 and p = 0.0002). The diagnosis cut-off points between benign and malignant tumours for ADC, FA and SWV were 1.02 × 10(-3) mm(2) s(-1), 0.24 and 2.76 m s(-1), respectively; the sensitivity for ADC, FA and SWV was 87.50, 62.50 and 68.75%; the specificity was 45.71, 82.86 and 97.14%. Analysis of the combination of the three parameters increased the sensitivity, specificity, Youden index and area under the ROC curve compared with analysis of each parameter alone for distinguishing benign and malignant tumours.

CONCLUSIONS

The diagnostic value of the combination of the three parameters for distinguishing benign and malignant parotid tumours is the best; SWV is the preferred indicator. Parameters of DTI and ARFI may reflect the histological characteristics of parotid tumours and predict benignancy and malignancy and could provide quantitative information about the tumour. Combination of DTI with ARFI imaging had obvious advantage for the diagnosis of parotid tumours than each alone.

Compression Real-time Elastography for Evaluation of Salivary Gland Lesions: A Meta-analysis

OBJECTIVES

To evaluate the performance of compression real-time elastography for differentiation between benign and malignant salivary gland lesions.

METHODS

A systematic literature database search was conducted. Pooled sensitivity, specificity, positive likelihood ratio (LR+), and negative likelihood ratio (LR-) values for real-time elastography were analyzed. Summary receiver operating characteristic (ROC) curves were also constructed. Heterogeneity was evaluated by χ(2) and I(2) tests. I(2) > 50% or P < .05 indicated heterogeneity, and then a random-effects model was applied. A Deek funnel plot was used to assess publication bias. Fagan plot analysis was performed to evaluate the clinical utility of real-time elastography. When heterogeneity was found, subgroup analyses were used to explore the sources of heterogeneity. A sensitivity analysis was conducted by omitting 1 study at a time and examining the influence of each individual study on the overall results.

RESULTS

Nine articles with 581 lesions were included. The pooled sensitivity and specificity of real-time elastography for differentiation between benign and malignant lesions were 76% (95% confidence interval [CI], 65%-85%; 95% prediction interval [PI], 29%-95%) and 73% (95% CI, 62%-81%; 95% PI, 24%-96%), respectively. The LR+ and LR- were 2.81 (95% CI, 1.79-4.39; 95% PI, 0.65-12.16) and 0.33 (95% CI, 0.20-0.55; 95% PI, 0.07-1.69). The area under the ROC curve was 0.81 (95% CI, 0.77-0.84). No publication bias was detected, according to the Deek funnel plot (P = .51). The Fagan plot showed that when pretest probabilities were 25%, 50%, and 75%, positive posttest probabilities were 48%, 74%, and 89%, and negative probabilities were 10%, 25%, and 50%.

CONCLUSIONS

Real-time elastography is a novel supplementary adjunct to conventional sonography for evaluation of salivary gland lesions. However, its overall accuracy is less promising, and biopsy may still be necessary in routine clinical practice.

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.

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.

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.

Sonography: the leading diagnostic tool for diseases of the salivary glands

Ultrasound examination is the imaging procedure with the best predictive diagnostic capability for the salivary glands. Due to the salivary glands' relatively superficial anatomical location, clear boundary from surrounding tissue and comparatively typical echogenicity, therefore sonography is ideal for diagnosis. In addition, the technical advances in recent years, including higher resolution, color Doppler sonography, contrast-enhanced ultrasound, elastography, and tissue harmonic have lead to an improvement in diagnostic accuracy of sonography further resulting in an expansion of the range of indications. Sonography allows detection of obstructive salivary gland diseases such as stenosis or sialolithiasis, as well as sialadenosis such as Sjögren syndrome. Ultrasound examination alone is sufficient to diagnose benign tumors. However, in the case of malignant tumors, computer tomography or MRI may be also required, especially to determine the question of infiltration of the skull base.

Quantitative assessment of bladder neck compliance by using transvaginal real-time elastography of women

To assess the feasibility of using ultrasound real-time elastography (RTE) to measure bladder neck compliance, we performed real-time elastography measurements by manually applying repetitive compression with the transducer on the scan position of the bladder neck. Instant elastography index (EI) and mean EI of anterior and posterior lips of the bladder neck were calculated. The EI values of anterior and posterior lips of the bladder neck were analyzed in relation to age, body surface area, body mass index, detrusor wall thickness and length, width and thickness of the bladder neck in healthy women. The intra-observer and inter-observer repeatability of measurements in different parts of the bladder neck were assessed using intra-class correlation coefficients with 95% confidence intervals and Bland-Altman analysis. There were no statistically significant differences between elastography measurements made by the same or two different observers in each area measured. There was no significant difference between anterior and posterior lip thickness of the bladder neck. The distribution of the elastography measurements indicated that the anterior lip of the bladder neck was slightly harder than the posterior lip. On the whole, from the results of the study, it was clear that EIs of the bladder neck were related to age in healthy women. Stepwise multiple regression analysis results revealed that age was the only independent factor modulating compliance of the bladder neck in healthy women. It is possible to provide a reproducible semi-quantification of real-time elastography in bladder neck compliance.

Application of real-time sonoelastography in musculoskeletal diseases related to physical medicine and rehabilitation

Real-time sonoelastography is a recently developed ultrasound-based technique that evaluates tissue elasticity in real time, and it is based on the principle that the compression of tissue produces a strain (displacement) that is lower in hard tissue and higher in soft tissue. Real-time sonoelastography provides information on tissue elasticity, in addition to the shape or vascularity, which is obtained via B-mode ultrasound. Similar to B-mode ultrasound, freehand manipulation with the transducer and real-time visualization are now available for real-time sonoelastography in actual clinical practice. Tissue elasticity not only varies among different tissues but also seems to reflect disease-induced alternations in tissue properties. Real-time sonoelastography was recently applied to the normal and pathologic tissues in muscle and tendon disorders, and it showed promising results and new potentialities. Therefore, it is expected to be a useful modality for providing novel diagnostic information in musculoskeletal diseases because tissue elasticity is closely related to its pathology. It can also be used as a research tool to provide insight into the biomechanics and pathophysiology of tissue abnormality.

Ultrasound elastography in the head and neck. Part II. Accuracy for malignancy

Ultrasound elastography (USE) describes a variety of ultrasound-based imaging techniques that measure tissue stiffness properties, and is currently under intense investigation for tissue characterization in several anatomic sites. This article summarizes the evidence regarding the accuracy of USE for malignancy in the head and neck. Currently, most published data pertains to small pilot studies with varied methodologies. Encouragingly, most studies have documented promising results for USE in terms of high accuracy for malignancy in thyroid nodules and cervical lymph nodes, which have surpassed conventional sonographic criteria. However, a minority of studies have documented opposite findings. USE seems to be suboptimal for salivary malignancies, and some evidence suggests that USE does not provide useful diagnostic information compared with conventional ultrasonography for miscellaneous neck masses. Further larger studies are required to validate these findings although, in view of the predominance of highly optimistic results for thyroid nodules and cervical lymph nodes, USE may become a useful ancillary technique in the routine diagnostic work-up of lesions in these tissues in the near future.

Early results of real-time qualitative sonoelastography in the evaluation of parotid gland masses: a study with histopathological correlation

BACKGROUND

Sonoelastography has been used to differentiate malignant from benign lesions in numerous types of tissues including breast, prostate, liver, blood vessels, thyroid, musculoskeletal structures, and salivary glands.

PURPOSE

To evaluate the efficacy and application of real-time qualitative sonoelastography in the differentiation of benign and malignant focal parotid gland lesions.

MATERIAL AND METHODS

A total of 75 patients (36 boys/men, 39 girls/women; age range, 10-83 years) with 81 lesions were evaluated prospectively by sonoelastography performed and interpreted by two expert radiologists. The results of these experts classification and scoring of lesions according to relative stiffness of the mass were compared with each other and with histopathological findings. The interpretation of sonoelastography scores of 1-4 were as follows: 1, soft; 2, mostly soft; 3, mostly stiff; and 4, stiff.

RESULTS

The kappa statistic of 0.508 (P < 0.001) indicated moderate agreement between the two radiologists. The sonoelastography scores correctly diagnosed 30 of 49 benign tumors (sensitivity, 61.2%) and 19 of 32 malignant tumors (specificity, 59.4%). The area under the receiver-operating characteristic curve was 0.603. The diagnostic value of sonoelastography for evaluating pleomorphic adenomas, Warthin tumors, adenoid cystic carcinoma, and high-grade tumors was low, whereas the diagnostic rates for low-grade tumors such as mucoepidermoid carcinoma, acinic cell carcinoma, and metastases of basal cell carcinoma were better with sonoelastography.

CONCLUSION

Although sonoelastography seems to be promising in the differentiating of low-grade malignancies, the primary role of radiology is currently limited to determination of localization, size, and morphology of parotid tumors.

Is sonoelastography a helpful method for evaluation of parotid tumors?

Sonoelastography is a novel technique, useful in a noninvasive assessment of lesions in multiple organs. The aim of the study was to examine whether the combination of conventional ultrasonography (US) with sonoelastography might improve the reliability of parotid tumor evaluation. Fourty-three consecutive patients with parotid tumors were surgically treated at a single tertiary center at the Department of Otolaryngology, Head and Neck Surgery. The sample included 27 women and 16 men, aged 15–80 (the mean age = 54 years). The reference group constituted of 54 healthy volunteers. High resolution grayscale ultrasonography (US) was performed preoperatively using a 15 MHz linear array transducer. Elastograms (ES) were scored by the conventional Ueno 5-point scale from ES1 (blue-soft) to ES5 (the entire lesion and surrounding area shaded red-stiff). In addition, detailed stiffness values in kPa were collected. The group consisted of 33 patients with benign and 10 patients with malignant tumors. The mean stiffness value was 146.6 kPa in 10 malignant tumors (mostly ES4) and 88.7 kPa in 33 benign tumors (mostly ES2 and ES3). The differences in tissue stiffness between normal parotid parenchyma in the reference group and the mean value for all tumors in the examined group were statistically significant (p < 0.001), and so was the case with the differences between the benign and malignant tumors (p < 0.001). Low stiffness scores (ES1,2) were found in 2 malignant and 15 benign tumors while high scores (ES3,4) were found in 8 malignancies and 18 benign tumors. Sonoelastography overlapping elasticity to the grayscale images supports additional informations. Preferential selection of the lesions characterized by high stiffness (ES4) improves the differential diagnosis of parotid tumors but the large degree of uncertainty of this method should also be pointed out.

Ultrasound GLCM texture analysis of radiation-induced parotid-gland injury in head-and-neck cancer radiotherapy: an in vivo study of late toxicity

PURPOSE

Xerostomia (dry mouth), secondary to irradiation of the parotid glands, is one of the most common side effects of head-and-neck cancer radiotherapy. Diagnostic tools able to accurately and efficiently measure parotid gland injury have yet to be introduced into the clinic. This study's purpose is to investigate sonographic textural features as potential imaging signatures for quantitative assessment of parotid-gland injury after head-and-neck radiotherapy.

METHODS

The authors have investigated a series of sonographic features obtained from the gray level co-occurrence matrix (GLCM) - a second order statistical method of texture analysis. These GLCM textural features were selected based on empirical observations that the normal parotid gland exhibits homogeneous echotexture, whereas the postradiotherapy parotid gland often exhibits heterogeneous echotexture. We employed eight sonographic features: (1) angular second moment (ASM), (2) inverse differential moment (IDM), (3) contrast, (4) variance, (5) correlation, (6) entropy, (7) cluster shade, and (8) cluster prominence. Altogether, sonographic properties of the parotid glands were quantified by their degrees of homogeneity (ASM and IDM), heterogeneity (contrast and variance), smoothness (correlation), randomness (entropy), and symmetry (cluster shade and prominence). The sonographic features were tested in a pilot study of 12 postradiotherapy patients and 7 healthy volunteers. The mean follow-up time for the postradiotherapy patients was 17.2 months (range: 12.1-23.9 months) and the mean radiation dose to the parotid glands was 32.3 Gy (range: 11.0-63.4 Gy). Each participant underwent one ultrasound study in which longitudinal (vertical) ultrasound scans were performed on the bilateral parotids - a total of 24 postirradiation and 14 normal parotid glands were examined. The 14 normal parotid glands served as the control group. A radiologist contoured the parotid glands on the B-mode images and the sonographic features were computed from the contoured region-of-interest.

RESULTS

The authors observed significant differences (p < 0.05) in all sonographic features between the normal and postradiotherapy parotid glands. The sonographic findings were consistent with the clinical observations of the ultrasound images: normal parotid glands exhibited homogeneous texture, while the postradiotherapy parotid glands exhibited heterogeneous echotexture (e.g., hyperechoic lines and spots), which likely represents fibrosis.

CONCLUSIONS

The authors have demonstrated the feasibility of ultrasonic texture evaluation of parotid glands; and the sonographic features may serve as imaging signatures to assess radiation-induced parotid injury.

A Novel Approach for Assessing the Progression of Deep Venous Thrombosis by Area of Venous Thrombus in Ultrasonic Elastography

Exact age determination of deep venous thrombosis (DVT) is important for an appropriate treatment. The purpose of this present study is to assess the age of acute DVT with the area of venous thrombi in elasticity imaging during the thrombosis procession. The thrombus area is obtained from a specially designed program. It was applied to clot specimens induced in human great saphenous (n = 15) at selected time points following the initiation of thrombosis. The relative mean proportion of blood clots was 50.01% ± 12.44% at day 1; 69.94% ± 8.19% at day 3; 81.93% ± 6.15% at day 6; and 92.37% ± 4.06% at day 9. The results indicated that the thrombus area increased significantly over time, while the normalized strain values inside the thrombus changed only a little. The pathological analyses also showed the same results. Therefore, we conclude that the area of venous thrombi in elasticity imaging may be a novel function for acute DVT staging.

Ultrasound histogram assessment of parotid gland injury following head-and-neck radiotherapy: a feasibility study

Xerostomia (dry mouth), resulting from radiation damage to the parotid glands, is one of the most common and distressing side effects of head-and-neck cancer radiotherapy. A noninvasive, objective imaging method to assess parotid injury is lacking, but much needed in the clinic. Therefore, we investigated echo histograms to quantitatively evaluate the morphologic and microstructural integrity of the parotid glands. Six sonographic features were derived from the echo-intensity histograms to assess the echogenicity, homogeneity and heterogeneity of the parotid gland: (1) peak intensity value (I(peak)), (2) -3-dB intensity width (W(3-dB)), (3) the low (<50% I(peak)) intensity width (W(low)), (4) the high (>50% I(peak)) intensity width (W(high)), (5) the area of low intensity (A(low)) and (6) the area of high intensity (A(high)). In this pilot study, 12 post-radiotherapy patients and seven healthy volunteers were enrolled. Significant differences (p < 0.05) were observed in four sonographic features between 24 irradiated and 14 normal parotid glands. In summary, we developed a family of sonographic features derived from echo histograms and demonstrated the feasibility of quantitative evaluation of radiation-induced parotid-gland injury.

Sonoelastographic qualitative analysis for management of salivary gland masses

OBJECTIVES

Our aim was to investigate whether the use of a qualitative elasticity scoring method by sonoelastography is beneficial for management of salivary gland masses.

METHODS

Thirty-six patients with salivary gland masses (30 parotid and 6 sub-mandibular) were prospectively included in this study. For each lesion, B-mode sonographic and sonoelastographic images were obtained. Elasticity scores were determined by a 4-point scoring method. Differences among scores for benign and malignant masses were assessed by the Mann-Whitney U test. Qualitative variables were compared by the Pearson χ² test. The findings were compared with histopathologic diagnoses.

RESULTS

The score values of 28 benign masses ranged from 1 to 4, whereas the values of 8 malignant masses ranged from 2 to 4. The mean scores ± SD were 2.25 ± 0.92 for benign lesions and 3.0 ± 0.75 for malignant lesions (P < .05). When we considered scores 1 and 2 as benign and scores 3 and 4 as malignant, 10 false-positive results were determined by the 4-point scoring method, and 64.2% of benign masses were diagnosed.

CONCLUSIONS

Sonoelastography might be regarded as another sonographic parameter for management of salivary gland masses in terms of detecting benign masses.

Contrast-enhanced ultrasound for monitoring effects of extracorporeal shock wave sialolithotripsy in sialolithiasis

OBJECTIVES/HYPOTHESIS

Contrast-enhanced ultrasound (CE-US) can be used for noninvasive analysis of functional vascularization. Chronically recurrent sialadenitis due to sialolithiasis of the submandibular gland is associated with increased vascularity. The aim of this investigator-initiated clinical trial was the evaluation of CE-US as a quantitative monitoring technique during gland-preserving extracorporeal shock wave sialolithotripsy (ESWL).

STUDY DESIGN

In this prospective clinical evidence level 2c study, perfusion in patients (n = 10) with unilateral sialolithiasis of the submandibular gland was quantitatively analyzed using CE-US before and after ESWL, comparing with the respective contralateral gland.

METHODS

Before CE-US measurements, a subjective clinical score of complaints (range, 1-10) was documented. The contrast agent SonoVue was injected into a cubital vein. The intensity-time curve gradients (ITGs) were calculated from CE-US data.

RESULTS

The ITGs derived from CE-US measurements revealed higher perfusion in the affected submandibular gland compared to the contralateral side. In parallel to clinical complaints, parametric CE-US data were significantly reduced after ESWL in chronic sialolithiasis-associated sialadenitis.

CONCLUSIONS

CE-US-derived ITGs appear to be an independent and quantitative marker for treatment effects of ESWL. Clinical experience and further studies will have to validate this method as a diagnostic tool to decide especially whether to proceed to sialoadenectomy in therapy-refractory cases.

Spastic cerebral palsy in children: dynamic sonoelastographic findings of medial gastrocnemius

PURPOSE

To study the elastic properties of the medial gastrocnemius (GCM) in children with spastic cerebral palsy.

MATERIALS AND METHODS

The study protocol was approved by the Research Ethics Committee of the hospital, and informed consent was obtained from each child's parent. Fifteen children with spastic cerebral palsy (group 1) and 13 children without neurologic and musculoskeletal disabilities (group 2) were included. Because group 1 included three children with hemiplegia, the total number of legs examined was 27. Children in group 2 had both legs examined, for a total of 26 legs studied. The modified Ashworth scale score of the ankle in group 1 was assessed by a physical therapist. A physiatrist performed ultrasonography and dynamic sonoelastography (DS) together, measured the thickness of the GCM, and calculated the GCM ratio in both groups. On color-scaled DS images, the DS score of the GCM was graded from DS 1 (purple to green: soft) to DS 4 (red: stiff), and the color histogram of the GCM was subsequently analyzed. Strain ratio and local shear wave velocity were calculated in the GCM and the soleus muscle by using acoustic radiation force impulse imaging.

RESULTS

The GCM ratio in group 1 was significantly smaller than that in group 2. The DS score of GCM in group 1 was significantly higher than that in group 2. The median red pixel values were significantly higher, and the blue pixel values were significantly lower on color histogram in group 1 than those in group 2. The strain ratio in group 1 was significantly lower than that in group 2, and the local shear wave velocity of GCM in group 1 was higher than that in group 2. There were significant correlations between the modified Ashworth scale scores and DS parameters.

CONCLUSION

DS demonstrated a difference in muscle stiffness in the GCM between children with spastic cerebral palsy and those without neurologic and musculoskeletal disabilities.