Initial experience of acoustic radiation force impulse ultrasound imaging of cervical lymph nodes

Cervical lymph node characterization using point shear wave elastography in pediatric patients: initial experience

BACKGROUND

Sonoelastography, also known as elastography, is a novel noninvasive imaging technique conducted using ultrasound equipment and used to indirectly evaluate tissue stiffness by measuring the speed of transverse wave propagation, or shear wave velocity, through the target tissue. Elastography is useful in diagnosing malignant lesions, which are stiffer than healthy tissue due to their high cell density.

OBJECTIVE

The aim of this study was to assess the ability of elastography to differentiate between benign and malignant cervical lymph nodes.

MATERIALS AND METHODS

Over a period of 2.5 years, we prospectively assessed the cervical lymph nodes of pediatric patients who visited the ultrasound department of our institution. In the course of a single procedure, participants underwent B-mode and color Doppler ultrasonography and point shear wave elastography (pSWE) of the cervical lymph nodes. The participants were divided into three groups: control (I), reactive lymph nodes (II), and malignant lymph nodes (III). A histological examination was performed in all patients with suspected malignancy, and mean shear wave velocity was compared across the three study groups.

RESULTS

Significant differences in elastography measurements were found between the lymph nodes in group I (control group) and group III (malignant lymph nodes) (P<0.0001) and between group II (reactive nodes) and group III (malignant nodes) (P<0.0001). Lymph nodes from patients in group III had higher elastography values than those in groups I and II.

CONCLUSION

pSWE is useful in measuring cervical lymph node stiffness, showing promising results in distinguishing between benign/reactive and malignant nodes.

Evaluation of acoustic radiation force impulse imaging in differentiating benign and malignant cervical lymphadenopathy

Background:

The aim of this study was to assess the diagnostic role of acoustic radiation force impulse imaging (ARFI) in differentiating benign and malignant cervical nodes.

Methods:

This was a diagnostic accuracy cross-sectional study. All patients who underwent ultrasound-guided fine-needle aspiration cytology (FNAC) of cervical nodes were included. Patients without FNAC/biopsy and patients in whom cervical nodes were cystic or completely necrotic were excluded. FNAC was used as reference investigation to predict the diagnostic accuracy. In all cases, FNAC was carried out after the B-mode, color Doppler and the ARFI imaging. In patients with multiple cervical lymph nodes, the most suspicious node based on grayscale findings was chosen for ARFI. ARFI included Virtual Touch imaging (VTI), area ratio (AR), and shear wave velocity (SWV) for each node, and the results were compared with FNAC/biopsy.

Results:

The final analysis included 166 patients. Dark VTI elastograms had sensitivity and specificity of 86.2% and 72.1%, respectively, in identifying malignant nodes. Sensitivity and specificity of AR were 71.3% and 82.3%, respectively, for a cutoff of 1.155. Median SWV of benign and malignant nodes was 1.9 [95% confidence interval (CI), 1.56–2.55] m/s and 6.7 (95% CI, 2.87–9.10) m/s, respectively. SWV >2.68 m/s helped in identifying malignant nodes with 81% specificity, 81.6% sensitivity, and 81.3% accuracy. ARFI was found to be inaccurate in tuberculous and lymphomatous nodes.

Conclusion:

Malignant nodes had significantly darker elastograms, higher AR and SWV compared to benign nodes, and SWV was the most accurate parameter. ARFI accurately identifies malignant nodes, hence could potentially avoid unwarranted biopsy.

The application of ultrasound shear wave elastography in the prediction of paradoxical upgrading reaction in tuberculous lymphadenitis. a pilot study

BACKGROUND

Paradoxical upgrading reaction (PUR) indicates the unanticipated deterioration during therapy in patients with tuberculous lymphadenitis. We investigated the diagnostic performance of the ultrasonography and shear wave elastography (SWE) in predicting the therapeutic response of peripheral tuberculous lymphadenitis.

METHODS

A prospective observational study was conducted from December 2017 to August 2020. Participants diagnosed with peripheral tuberculous lymphadenitis were included for a longitudinal follow-up utilizing ultrasonography with two-dimensional SWE to record sonographic features and the maximum elasticity value (Emax). We defined PUR as the development of any worsening symptoms of the pre-existing lymphadenitis within one month after the previous ultrasonography.

RESULTS

A total of 108 sonographic and SWE examinations were performed in 20 enrollees (75% woman), and their mean ( ± standard deviation) age was 49.6 ( ± 22.7) years. The area under the receiver operating characteristic curve of Emax to predict the next-month PUR was 0.906 at the cut-point of 85 kPa, with an accuracy of 87.0%, a sensitivity of 81.1% and a specificity of 87.9%. Multivariate analysis indicated that Emax > 85 kPa (OR: 24.85, 95% CI: 4.01-154.08, p < 0.001), Emax increment rate >2 kPa/month (OR: 15.14, 95% CI: 4.24-54.06, p < 0.001), and heterogeneous echogenicity (OR: 4.37, 95% CI: 1.16-16.43, p = 0.029) were independent sonographic predictors for PUR in the coming month.

CONCLUSIONS

A high and non-declining Emax level and heterogeneous echogenicity were associated with the next-month PUR of tuberculous lymphadenitis. Ultrasonography with SWE may be a potential radiologic marker to predict the therapeutic response of tuberculous lymphadenitis.

Ultrasound Elastography for the Evaluation of Lymph Nodes

The differential diagnosis of lymphadenopathy is important for predicting prognosis, staging, and monitoring the treatment, especially for cancer patients. Conventional computed tomography and magnetic resonance imaging characterize lymph node (LN) with disappointing sensitivity and specificity. Conventional ultrasound with the advantage of high resolution has been widely used for the LN evaluation. Ultrasound elastography (UE) using color map or shear wave velocity can non-invasively demonstrate the stiffness and homogeneity of both the cortex and medulla of LNs and can detect early circumscribed malignant infiltration. There is a need of a review to comprehensively discuss the current knowledge of the applications of various UE techniques in the evaluation of LNs. In this review, we discussed the principles of strain elastography and shear wave-based elastography, and their advantages and limitations in the evaluation of LNs. In addition, we comprehensively introduced the applications of various UE techniques in the differential diagnosis of reactive LNs, lymphoma, metastatic LNs, and other lymphadenopathy. Moreover, the applications of endoscopic UE and endobronchial UE are also discussed, including their use for improving the positive rate of diagnosis of fine-needle aspiration biopsy.

A nomogram for predicting the risk of neck node metastasis in oral cavity carcinoma using acoustic radiation force impulse imaging (ARFI)

BACKGROUND

The study was conducted to assess the accuracy power of Acoustic radiation force impulse imaging (ARFI) and generate a nomogram using ultrasound and ARFI to predict malignant cervical lymph nodes in head and neck squamous cell carcinoma.

MATERIAL AND METHODS

374 cervical lymph nodes from 67 patients were evaluated. The B-mode ultrasonography and the elastography findings were compared with the final histopathological diagnosis. Radiological variables were used to construct nomogram and clinical utility of the nomogram was cross-validated.

RESULTS

In univariate analysis, status of the hilum, Long Axis Diameter, Short axis diameter, colour virtual touch imaging grade (VTI) and shear wave velocity were significant in predicting metastasis in the cervical lymph nodes. In multivariable analysis, it was found that predominance of red over yellow area on colour VTI was significantly associated with lymph node metastasis. A multiple logistic regression performed to ascertain the effects of on the likelihood that patients had lymph node metastasis on histopathology was statistically significant, χ2(10) = 44.96, p < 0.001. The model was able to correctly classify 93.28% of cases and the concordance index (c-index) was estimated to be 0.8773. A nomogram was thus established to predict metastasis in cervical lymph nodes.

CONCLUSIONS

ARFI increases the diagnostic accuracy of conventional USG in predicting metastatic lymph nodes in HNSCC. Adding the constructed nomogram to the conventional diagnostic pathway can provide an alternative option to frozen section and FNAC.

ACR Appropriateness Criteria® Neck Mass-Adenopathy

A palpable neck mass may be the result of neoplastic, congenital, or inflammatory disease. Older age suggests neoplasia, and a congenital etiology is more prevalent in the pediatric population. The imaging approach is based on the patient age, mass location, and clinical pulsatility. Underlying human papillomavirus-related malignancy should be considered in all age groups. Although the imaging appearance of some processes in the head and neck overlap, choosing the appropriate imaging examination may allow a specific diagnosis, or a limited differential diagnosis. Tissue sampling is indicated to confirm suspected malignancy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Usefulness of 2-D shear wave elastography for the diagnosis of inguinal lymph node metastasis of malignant melanoma and squamous cell carcinoma

We used 2‐D shear wave elastography to quantify lymph node hardness, from the shear wave velocity, to determine the presence or absence of metastatic lymphadenopathy in the inguinal lymph nodes of five patients with malignant melanoma and squamous cell carcinoma. The shear wave velocity accurately identified all cases of metastasis confirmed by histology, compared with two false‐positive and one false‐negative finding with positron emission tomography/computed tomography. 2‐D shear wave elastography would be useful to evaluate inguinal lymph node metastasis.

Role of Ultrasound Acoustic Radiation Force Impulse in Differentiating Benign from Malignant Superficial Lymph Nodes

Objective:

The purpose of this study was to evaluate the diagnostic performance of acoustic radiation force impulse (ARFI) imaging in differentiating benign from malignant peripheral lymphadenopathy.

Materials and Methods:

This was a prospective study approved by the Institutional Review Board with financial grant for the same. Ultrasound and ARFI imaging of peripheral lymph nodes were performed and correlated with pathological results, which were used as the reference standard. The virtual touch tissue imaging and virtual touch tissue quantification parameters of ARFI were analyzed in 86 lymph nodes, of which 78 were included in the study. Using receiver operating characteristic curve analysis, the diagnostic usefulness of ARFI values were evaluated with respect to their sensitivity, specificity, and area under the curve.

Results:

The mean area ratio of benign lymph nodes was 0.88 (±0.2) and that of malignant lymph nodes was 1.17 (±0.14). The mean shear wave velocities (SWV) of benign and malignant lymph nodes were 2.02 m/s (±0.94) and 3.7 m/s (±2.27), respectively. The sensitivity and specificity of virtual touch imaging area ratio in differentiating benign from malignant lymph nodes was 97% and 77%, of SWV was 71% and 70%, and of SWV ratio was 68% and 79%, respectively.

Conclusion:

As ARFI was found to have a superior diagnostic performance over conventional ultrasound and color Doppler in the characterization of lymph nodes, we recommend its routine use in differentiating benign from malignant nodes.

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

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

Differentiating cervical metastatic lymphadenopathy and lymphoma by shear wave elastography

Shear wave elastography (SWE) is a recent technological advance of ultrasonography (US) to assess tissue stiffness. The purpose of this study is to assess tissue stiffness of malignant cervical lymph nodes (LN) with SWE, to reveal diagnostic performance of SWE in differentiating metastatic LN from lymphoma, and to assess inter-observer agreement of SWE. We assessed 62 malignant LN (24 lymphomas and 38 metastatic LN) and their median speed was 6.34 m/s and median elasticity was 69.7 kPa. Add of SWE with conventional US improved diagnostic accuracy of differentiating metastasis from lymphoma (16.13, 8.07 and 11.3% for three radiologists). Kendall’s Coefficient of Concordance of three readers for analyzing SWE patterns was 0.86. SWE can be a useful tool to discriminate metastatic cervical LN from lymphoma with improvement of diagnostic accuracy when using with conventional US.

The Role of Ultrasound and Shear-Wave Elastography in Evaluation of Cervical Lymph Nodes

Aim

To evaluate the prognostic value of ultrasound and shear-wave elastography (SWE) in diagnosing malignant cervical lymph nodes.

Methods

A total of 99 patients with enlarged lymph nodes (99 lymph nodes presenting as a neck mass) were examined clinically with conventional ultrasound including Doppler examination and shear-wave elastography. The results of the examinations were compared with the final diagnosis.

Results

There were 43 benign and 56 malignant lymph nodes in our cohort. Age and sex were significant predictors of malignancy. The standard ultrasound parameters—node size, long/short axis ratio, hilum, vascularization, and the presence of microcalcifications—were also statistically significant. Lymph node volume combined with age showed the best predictive power. The maximum stiffness found on SWE was also a significant predictor of malignancy. The combination of epidemiologic, classic ultrasound, and elastographic parameters yielded the highest sensitivity and specificity in the prediction of malignancy; however, the additional impact of elastographic parameters was low.

Conclusion

A combination of epidemiologic and classic ultrasound parameters can discriminate between malignant and benign lymph nodes with satisfactory sensitivity and specificity. Examining the stiffness of lymph nodes by means of SWE does not add much new predictive power.

Experience of Using Shear Wave Elastography Imaging in Evaluation of Undescended Testes in Children: Feasibility, Reproducibility, and Clinical Potential

We aimed to determine the difference in tissue stiffness, which might reflect histologic damage, by comparing the potential of the shear wave elastography (SWE) values of operated undescended testes (OUT) with those of undescended testes (UT) and normal testes. A total of 120 patients (235 testes) were enrolled in the current study. Quantitative SWE values were measured by manually drawing contours of the entire testis structure with a free region of interest. A group of 66 OUT were classified as group A. Operation age and the period passed over the operation time and SWE values were compared among the testes assigned to group A. The 50 testes having inguinal canal placement were classified as group B, and the 119 testes whose sonography findings were normal were classified as group C. These 3 groups were compared in terms of the SWE values and volume. The SWE values of group A were significantly higher than those of groups B and C (P < 0.001). The SWE values of group B were significantly higher than those of group C (P < 0.001). The SWE values of OUT were significantly higher than those of the contralateral normal testes and UT (P < 0.001). There were no significant differences among operation age and period passed over the operation time and SWE values in the OUT (P > 0.05). There was no significant correlation between SWE values and testes' volume (P > 0.05). The SWE technique can be used effectively as a new parameter to assess stiffness of the OUT and UT to predict interstitial fibrosis and the severity of histologic damage.

The role of ARFI elastography to evaluate microstructrual changes of patients with testicular microlithiasis

BACKGROUND

Testicular microlithiasis (TML) is thought to cause microstructural changes in the parenchyma of the testis, but it is difficult to demonstrate this by ultrasonography. It may be possible to evaluate microstructural changes in the testis by Acoustic Radiation Force Impulse (ARFI) elastography, which measures tissue stiffness.

PURPOSE

To assess the tissue stiffness of testicles of children with TML and to compare them with the healthy control group.

MATERIAL AND METHODS

Between November 2015 and May 2016, 25 pediatric patients with TML and 24 healthy children were enrolled in the study (mean age for TML and control group 6.7 ± 3.17 and 7.9 ± 4.18 years, respectively). Testicular volumes and mean shear wave velocity (SWV) values were calculated and compared with each other in both groups.

RESULTS

There was no significant difference in average testicular volumes between the TML group and the control group (1.14 cm3, 1.21 cm3, respectively; P = 0.986). Mean SWV of the testicles with TML and normal testicles with control group was 1.18 ± 0.22 cm/s and 0.88 ± 0.11 cm/s, respectively. The SWV of the testicles with TML was higher than the normal testicles and this was statistically significant ( P < 0.001).

CONCLUSION

This study has shown that tissue stiffness in patients with TML is increased compared to the normal population. ARFI elastography helps the early detection of microstructural changes in TML and can be used for screening and follow-up.

Is Acoustic Radiation Force Impulse (ARFI) Ultrasound Elastography Valuable in the Assessment of Cervical Lymphadenopathy?

Cervical lymphadenopathy frequently poses a diagnostic challenge as neither clinical nor imaging assessment can reliably differentiate between benign and malignant lymphadenopathy. Non-invasive differentiation between the two may help to reduce the number of FNAC or biopsy. The purpose of this study was to evaluate whether the new ARFI technique (Virtual Touch Quantification), in conjunction with gray scale sonography and Doppler, can help in the characterization and differentiation of benign from malignant cervical lymphadenopathy. Fifty adult patients with cervical lymphadenopathy were included in the study and sonoelastography was done. Sonoelastographic findings were compared to the gold standard histopathology or cytopathology. ARFI measurements in benign and malignant enlarged lymph nodes were compared using the Student t test and ROC curve was used to arrive at the Youden index, sensitivity, specificity, PPV, NPV and diagnostic accuracy. Sonographic patterns indicative of malignancy includes heterogenous echopattern, short axis/long axis ratio > 0.5, absent echogenic fatty hilum and mixed vascular pattern. Sensitivity, specificity, PPV, NPV and accuracy in differentiation between the benign and malignant lymph nodes using ARFI elastography was 79.17, 100, 100, 83.9 and 89.9% respectively. ROC curve analysis of SWVs for differentiation between the malignant and benign lymph nodes gave a cut-off value of 2.8 m/s with an area under curve of 0.892. ARFI imaging technique quantifies the tissue stiffness of the cervical lymph nodes non-invasively and aids in characterisation and differentiation of benign from malignant cervical lymphadenopathy in conjunction with conventional sonography.

Elastography as a potential modality for screening cervical lymph nodes in patients with papillary thyroid cancer: A review of literature

Papillary thyroid cancer often presents with cervical lymph node involvement and has a high incidence of recurrence, which requires routine follow-up with ultrasound imaging. Elastography is a novel ultrasound technique that has been demonstrated to be effective clinically in detecting tissue pathology in areas such as the liver and breast. Preliminary data suggest that it may be effective in screening tissues in the neck for malignancy, specifically cervical lymph nodes. However, diagnostic criteria and elastographic techniques vary significantly among the studies we have reviewed, which all tend to focus on populations of patients with many different types of primary malignancies. Further research is required on the feasibility of creating standardized and reproducible clinical criteria in a specific patient population. To study the clinical utility of elastography in cervical lymph nodes, patients with diagnosed papillary thyroid carcinoma may serve as an ideal population because of their need for ultrasound surveillance and the propensity of papillary thyroid cancer to metastasize to and recur in cervical lymph nodes. We will review the limitations, techniques, and reported clinical utility of elastography on cervical lymph nodes and its potential as a screening modality for papillary thyroid cancer.

Syncope caused by a pleomorphic adenoma: Case report and literature review

Pleomorphic adenomas are considered the most common salivary gland tumors, although they rarely occur in the parapharyngeal space. To the best of our knowledge, this is the first case report of a parapharyngeal parotid pleomorphic adenoma causing syncope. A 57-year-old man was admitted for left-sided blurred vision, left-sided weakness, dysarthria, lightheadedness, and syncope. Upon his admission, an electrocardiogram showed sinus bradycardia, and computed tomography of the neck with contrast showed a large parapharyngeal mass involving the prestyloid compartment, leading to compression of blood flow through the internal carotid artery. The mass was biopsied via intraoral fine-needle aspiration, which revealed cytology consistent with pleomorphic adenoma. The mass was resected via a transcervical approach, and a total parotidectomy was performed. The patient's hypotensive and bradycardic episodes disappeared after surgery. Surgical pathology showed a benign pleomorphic adenoma with a hemorrhagic and necrotic center and without capsular invasion or malignant transformation.

Acoustic radiation force impulse imaging of biopsy-proven Kikuchi disease: initial experiences for evaluating feasibility in pediatric patients

Purpose

This study evaluated the feasibility of acoustic radiation force impulse (ARFI) elastography and characterized the sonographic features of lymph nodes (LNs) with Kikuchi disease in pediatric patients.

Methods

Seventy-six cervical LN biopsies were performed for the diagnosis of cervical lymphadenopathy. ARFI imaging was performed, and the characteristic ultrasound features of the biopsied LNs and the contralateral LNs were analyzed. We also reviewed clinical and conventional ultrasonographic findings.

Results

On histology, 56 patients were diagnosed with Kikuchi disease. These LNs were large and elongated, with increased perinodal echogenicity and capsular thickening. In 38 of them, ARFI elastography was performed, and the median shear wave velocity (SWV) of the biopsied LNs with Kikuchi disease (2.19 m/sec; range, 1.45 to 4.57 m/sec) was higher than of the contralateral LNs (1.72 m/sec; range, 0.95 to 2.65 m/sec; P<0.001). In patients with reactive hyperplasia, the mean SWV of the biopsied LNs (2.00 m/sec; range, 1.49 to 2.26 m/sec) was higher than that of the contralateral LNs (1.55 m/sec; range, 1.21 to 2.32 m/sec; P=0.031).

Conclusion

The SWV of LNs with Kikuchi disease was significantly higher than that of the contralateral LNs. Morphologically, LNs with Kikuchi disease showed an enlarged, elongated, and oval shape, increased perinodal echogenicity, and capsular thickening. In addition to the conventional ultrasonographic findings, the application of ARFI is feasible even in pediatric patients for the evaluation of cervical lymphadenopathy.

Experience of Using Shear Wave Elastography Imaging in Superficial Venous Insufficiency of the Lower Extremity

We investigated the effectiveness of shear wave elastography (SWE) in patients with lower extremity superficial venous insufficiency (VI). A total of 138 symptomatic patients, 51 asymptomatic volunteers, and a total of 359 lower extremities (257 symptomatic, 102 asymptomatic) were examined. All participants underwent Doppler ultrasound (US) evaluation to determine VI and SWE measurements performed by manually drawing vein wall and perivenous tissue with free region of interest at the great saphenous vein (GSV) and small saphenous vein (SSV). The GSV, SSV diameter, VI, and volume flow of reflux were compared with the SWE values. The SWE values of the symptomatic group for GSV and SSV were significantly higher than those of the asymptomatic control group regardless of whether VI was detected by Doppler US (P < 0.001). There was a statistically significant increase in SWE values for the symptomatic group who were diagnosed as having reflux in GSV and SSV (P < 0.001). A significant positive correlation between increased GSV, SSV diameter, and SWE values was seen (P < 0.001). Venous insufficiency can be diagnosed with a 84.7% sensitivity and 84.2% specificity when 2655 m/s was designated as cutoff value, and with a 85.4% sensitivity and 84.2% specificity when 22,350 kPa was designated as the cutoff value in GSV. Venous insufficiency can be diagnosed with a 84.3% sensitivity and 82.4% specificity when 2845 m/s was designated as cutoff value, and with a 85.7% sensitivity and 84.4% specificity when 27,100 kPa was designated as the cutoff value in SSV. Shear wave elastography may be used effectively in addition to conventional Doppler US examination in diagnosing and following VI.

Diagnostic value of acoustic radiation force impulse imaging for assessing superficial lymph nodes: A diagnostic accuracy study

The aim of this study was to assess the diagnostic value of acoustic radiation force impulse (ARFI) imaging for differentiating superficial lymph nodes.Virtual touch tissue imaging (VTI) grade and shear wave velocity (SWV) were analyzed and compared in 97 patients (65 women, 32 men; mean age, 49 y; range, 23-72 y) with 97 lymph nodes [23 chronic nonspecific reactive lymph nodes (CLNs), 38 metastatic lymph nodes (MLNs), and 36 blood and lymphatic system diseases lymph nodes (BLLNs)]. The elastography characteristics in patients with CLNs, MLNs, and BLLNs were compared using the nonparametric Kruskal-Wallis test and Mann-Whitney U test for continuous variables and categorical variables. The diagnostic performance of VTI grade and SWV were evaluated using the area under the receiver operating characteristic curve (AUC).The median of SWV of MLNs was significantly higher (2.90 m/s) than those of CLNs (2.15 m/s) and BLLNs (2.52 m/s). The VTI grade of MLNs was significantly higher than those of CLNs (P < .001) and BLLNs (P < .001). The sensitivity, specificity, accuracy, and AUC were 81.58%, 95.65%, 86.89%, and 0.904, respectively, at a cutoff level of grade IV for VTI grade in differentiating MLNs from CLNs, whereas those of SWV were 57.89%, 86.96%, 68.85%, and 0.752, respectively, at a cutoff level of 2.76 m/s.The diagnostic performance of VTI grade was significantly higher than that of SWV in differentiating MLNs from CLNs. The diagnostic performance of VTI grade and SWV were lower intermediate in differentiating MLNs from BLLNs and in differentiating BLLNs from CLNs, and there was no significant difference between VTI grade and SWV. ARFI imaging may be a feasible method for differentiating MLNs from CLNs.

Evaluation of Inferior Turbinate Stroma with Ultrasound Elastography in Allergic Rhinitis Patients

Background:

Diagnosis of allergic rhinitis is primarily based on history, physical examination and allergy testing. A technique that noninvasively evaluates the soft tissue changes in the nasal mucosa of allergic rhinitis patients has not been defined.

Aims:

To assess nasal mucosal changes and measure the submucosal fibrosis in allergic rhinitis patients with sonoelastography.

Study Design:

Case control study.

Methods:

Eighty-eight turbinates of 44 patients were included in the study. There were 23 prick test positive allergic rhinitis patients. The control group constituted 21 patients. The rhinitis quality of life questionnaire and the visual analogue scale were applied to the allergic rhinitis patients. A higher visual analogue scale score indicated more severe allergic rhinitis symptoms. Sonoelastographic measurements were made from the lateral nasal wall. The propagation speed of sound waves was recorded in m/s. The presence of asthma and the type of allergic rhinitis (seasonal or perennial) was noted.

Results:

Ten patients had seasonal allergic rhinitis and thirteen patients had perennial allergic rhinitis. Six patients (26.1%) had accompanying asthma along with allergic rhinitis. The median visual analogue scale score was 7 (3-9) in allergic rhinitis patients. The median symptom duration was 7 (1-24) months. The median quality of life questionnaire score was 3.39 (1.68-5.43) points. The median sonoelastography scores of allergic rhinitis patients and healthy subjects were 2.38 m/s (0.9-4.47) and 2.42 m/s (1.62-3.50), respectively. Sonoelastographic measurements of seasonal and perennial allergic rhinitis patients did not differ significantly (p>0.05). The presence of asthma did not have a significant impact on the elastography measurements (p>0.05). However, regression analysis revealed a significant inverse correlation (coefficients: B=0.005, standard error=0.097, beta 0=0.008) between the visual analogue scale and sonoelastography scores (p<0.05).

Conclusion:

Sonoelastography was not suitable as a diagnostic tool in allergic rhinitis. Reduced sonoelastography scores were measured in more symptomatic patients. Higher visual analogue scale scores could be an indicator of disease severity.

Value of Shear Wave Elastography Versus Contrast-Enhanced Sonography for Differentiating Benign and Malignant Superficial Lymphadenopathy Unexplained by Conventional Sonography

OBJECTIVES

This study aimed to compare the efficacy of shear wave elastography (SWE) and contrast-enhanced sonography in the differential diagnosis of superficial lymphadenopathy with abnormal imaging findings, which could not be otherwise confirmed by conventional sonography.

METHODS

Forty-two enlarged superficial lymph nodes in 42 patients who met the screening criteria for this study were evaluated by both contrast-enhanced sonography and SWE. All lymph nodes underwent both methods using biopsy pathologic findings as a reference standard.

RESULTS

The maximum elastic modulus, mean elastic modulus, and standard deviation of the elastic modulus were the main distinguishing features on SWE; they were significantly higher in malignant lesions than benign ones. The threshold value for the maximum elastic modulus was set at 37.9 kPa, and the sensitivity, specificity, and accuracy of differential diagnosis of superficial lymph nodes were 81.8%, 80.0%, and 81.0%, respectively. The diagnosis of benignity and malignancy by this index was statistically significant (P < .001). The lymph nodes were divided into benign and malignant groups according to different types based on the degree and range of intensity on contrast-enhanced sonography: intense or moderate homogeneous enhancement (n = 26) and heterogeneous, low homogeneous, or absent enhancement (n = 16). The sensitivity, specificity, and accuracy of contrast-enhanced sonography were 27.3%, 50.0%, and 38.1%. There was no statistically significant difference in the values between the benign and malignant groups (χ²  = 2.295; P = .130).

CONCLUSIONS

Compared with contrast-enhanced sonography, SWE has better diagnostic value and efficiency in differentiation of superficial lymph nodes unexplained by conventional sonography. When conventional sonography cannot differentiate malignant superficial lymph nodes from benign ones, SWE is a useful adjunctive tool for assessment of lymph nodes.

Acoustic Radiation Force Impulse Imaging for the Differentiation of Benign and Malignant Lymph Nodes: A Systematic Review and Meta-Analysis

Objective

To evaluate the overall performance of acoustic radiation force impulse imaging (ARFI) in differentiating between benign and malignant lymph nodes (LNs) by conducting a meta-analysis.

Methods

PubMed, Embase, Web of Science, the Cochrane Library and the China National Knowledge Infrastructure were comprehensively searched for potential studies through August 13th, 2016. Studies that investigated the diagnostic power of ARFI for the differential diagnosis of benign and malignant LNs by using virtual touch tissue quantification (VTQ) or virtual touch tissue imaging quantification (VTIQ) were collected. The included articles were published in English or Chinese. Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used to evaluate the methodological quality. The pooled sensitivity, specificity, and the area under the summary receiver operating characteristic (SROC) curve (AUC) were calculated by means of a bivariate mixed-effects regression model. Meta-regression analysis was performed to identify the potential sources of between study heterogeneity. Fagan plot analysis was used to explore the clinical utilities. Publication bias was assessed using Deek’s funnel plot.

Results

Nine studies involving 1084 LNs from 929 patients were identified to analyze in the meta-analysis. The summary sensitivity and specificity of ARFI in detecting malignant LNs were 0.87 (95% confidence interval [CI], 0.83–0.91) and 0.88 (95% CI, 0.82–0.92), respectively. The AUC was 0.93 (95% CI, 0.90–0.95). The pooled DOR was 49.59 (95% CI, 26.11–94.15). Deek’s funnel plot revealed no significant publication bias.

Conclusion

ARFI is a promising tool for the differentiation of benign and malignant LNs with high sensitivity and specificity.

Testicular microlithiasis and preliminary experience of acoustic radiation force impulse imaging

Background

Elastography of the testis can be used as a part of multiparametric examination of the scrotum.

Purpose

To determine the testicular stiffness using acoustic radiation force impulse imaging (ARFI) technique in men with testicular microlithiasis (TML).

Material and Methods

In 2013, 12 patients with diagnosed testicular microlithiasis in 2008 (mean age, 51 years; age range, 25–76 years) underwent a 5-year follow-up B-mode ultrasonography with three ARFI elastography measurements of each testis. We used a Siemens Acuson S3000 machine.

Results

No malignancy was found at the 5-year follow-up B-mode and elastography in 2013. However, we found an increase in TML; in the previous ultrasonography in 2008, eight men had bilateral TML, whereas in 2013, 10 men were diagnosed with bilateral TML. The mean elasticity of testicles with TML was 0.82 m/s (interquartile range [IQR], 0.72–0.88 m/s; range, 65–1.08 m/s).

Conclusion

Elastography velocity of testis with TML seems to be in the same velocity range as in men with normal testis tissue.

Assessment of Measurement Repeatability and Reliability With Virtual Touch Tissue Quantification Imaging in Cervical Lymphadenopathy

OBJECTIVES

The purpose of this study was to prospectively assess the repeatability and reliability of 2 measurements of cervical lymphadenopathy using Virtual Touch tissue quantification (VTQ) imaging (Siemens Medical Solutions, Mountain View, CA) and to analyze the factors affecting the reliability of the measurements, including pathologic findings, lesion size and location, and shear wave velocities (SWVs).

METHODS

In this Institutional Review Board-approved prospective study, 92 patients underwent conventional sonography and 2 VTQ measurements by acoustic radiation force impulse imaging in a single session. The repeatability and reliability of the SWV measurement was determined by using an average coefficient of variation (standard deviation/mean) and intraclass correlation coefficient (ICC), respectively. By comparing ICCs with a 95% confidence interval, the effects of pathologic findings, depth, size, SWV, and distance from the carotid artery on reliability were assessed.

RESULTS

The mean age of the 92 patients included in the study was 51 years (range, 14-77 years). The average coefficient of variation was 19.4%. The overall reliability of the 2 measurements was excellent (ICC, 0.837), but ICCs were significantly decreased in lymph nodes in a superficial location (<1 cm) and those with a low SWV (<1.8 m/s). No significant effect was found on reliability in relation to pathologic findings, lesion size, or distance from the carotid artery to the lymph nodes.

CONCLUSIONS

For SWV measurement by VTQ imaging, the repeatability was 19.4%, and reliability was excellent. However, caution is warranted in the use of VTQ imaging for superficial soft cervical lymph nodes, as both a superficial location and a soft composition tend to be characterized by low reliability of SWV findings.

Virtual Touch Tissue Imaging Quantification Shear Wave Elastography: Prospective Assessment of Cervical Lymph Nodes

The goal of this study was to prospectively evaluate the diagnostic performance of Virtual Touch tissue imaging quantification (VTIQ) shear wave elastography in the discrimination of benign and malignant cervical lymph nodes in routine clinical practice. Shear wave velocity was analyzed using VTIQ in 100 patients with 100 histologically proven cervical lymph nodes. Diagnostic performance was evaluated using receiver operating characteristic curve analysis and leave-one-out cross-validation. Agreement between measurements was assessed with intra-class correlation coefficients. The mean shear wave velocity was significantly higher in metastatic lymphadenopathy (4.46 ± 1.46 m/s) than in benign lymphadenopathy (2.71 ± 0.85 m/s) (p < 0.001) at a cutoff level of 3.34 m/s. The cross-validated accuracy, sensitivity and specificity were 77%, 78.9% and 74.4%, respectively. Agreement of measurements with VTIQ was excellent (intra-class correlation coefficient = 0.961). VTIQ shear wave elastography may be a feasible quantitative imaging method for differentiating benign and malignant cervical lymph nodes.

A novel method for comparison of tissue fibrosis after inferior turbinate surgery: ultrasound elastography

BACKGROUND

Ultrasound (US) elastography has been widely used for thyroid, liver, and lymph nodes as a research tool in the current medical practice. It has been described in the inferior turbinates and validated as a reliable, reproducible, noninvasive, and objective method that can detect the fibrosis-related tissue strain. There is no previous study that investigated the amount of fibrosis induced by radiofrequency and bipolar electrocautery in the inferior turbinates in a noninvasive and objective manner. The aim of this study was to assess the amount of inferior turbinate soft tissue fibrosis that was induced by radiofrequency ablation (RFA) and submucosal bipolar diathermy (SBD) by US elastography.

METHODS

Thirty-eight inferior turbinates of 19 patients were included. RFA was applied to 18 inferior turbinates (group 1) and SBD was applied to 20 inferior turbinates (group 2). US elastography and visual analog scale (VAS) assessments were performed on all patients preoperatively and 6 months postoperatively.

RESULTS

Preoperative mean US elastography scores in groups 1 and 2 were 2.55 ± 0.78 m/s and 2.56 ± 0.49 m/s, respectively (p < 0.05). Postoperative mean US elastography scores in groups 1 and 2 were 2.91 ± 1.03 m/s and 3.41 ± 0.86 m/s, respectively (p < 0.05). Preoperative mean VAS scores in groups 1 and 2 were 2.78 ± 0.94 and 2.50 ± 1.15, respectively. Postoperative mean VAS scores in groups 1 and 2 were 6.61 ± 1.61 and 6.10 ± 1.4, respectively (p < 0.05). Correlation of US elastography and VAS scores was insignificant (p > 0.05).

CONCLUSION

Both RFA and SBD of the inferior turbinates were effective in inducing scar tissue and, eventually, fibrosis in the soft tissue of inferior turbinates. Cauterization has been found to cause significantly higher amounts of fibrosis than radiofrequency; however, it did not reflect the comparable clinical outcome. This is the first study that objectively and noninvasively evaluates the targeted tissue fibrosis of the inferior turbinate surgeries by the novel inferior turbinate US elastography.

A new insight for evaluation of the inferior turbinate with ultrasound elastography

OBJECTIVES

There are diseases that affect the stroma of the inferior turbinate and many surgical interventions that alter it. However, an objective method that can evaluate the turbinate's stromal structure in detail has not been defined yet. The primary aim of this study was to investigate the effectiveness and reliability of ultrasound elastography for objective evaluation of the inferior turbinate stroma and define the most suitable elastographic technique.

METHODS

Twenty inferior turbinates in 10 healthy participants were included. Five of the participants (50%) were male, and 5 (50%) were female, with a mean age ± SD of 28.3 ± 3.2 years (range, 26-35) years. To obtain reliable and reproducible results, elastography was performed twice, 3 days apart, with and without a topical decongestant to evaluate the effects of the nasal cycle and mucosal edema. Two previously described valid elastographic outcome measures were reevaluated for the inferior turbinate. The tissue strain ratio and sound wave propagation speed were calculated for each measurement.

RESULTS

Median propagation speeds without and with the decongestant for the first and second measurements were 2.125 (interquartile range [IQR], 0.85), 2.175 (IQR, 0.53), 2.520 (IQR, 0.79), and 2.555 (IQR, 0.53) m/s, respectively. Median turbinate stroma-to-subcutaneous tissue strain ratios without and with the decongestant for the first and second measurements were 1.402 (IQR, 0.96), 0.942 (IQR, 0.24), 1.035 (IQR, 0.98), and 1.427 (IQR, 1.68).

CONCLUSIONS

We suggest that elastography is a reliable and reproducible method that is not substantially affected by mucosal edema. It is a novel technique that can evaluate the inferior turbinate stroma and might be used in concordance with other objective functional techniques such as acoustic rhinometry. Therefore, it can be used in further studies regarding diagnosis of turbinate diseases and objective evaluation of previous surgical treatments.

A comparative study of strain and shear-wave elastography in an elasticity phantom

OBJECTIVE. The purpose of this study was to assess the diagnostic accuracy of strain and shear-wave elastography for determining targets of varying stiffness in a phantom. The effect of target diameter on elastographic assessments and the effect of depth on shear-wave velocity were also investigated. MATERIALS AND METHODS. We examined 20 targets of varying diameters (2.5-16.7 mm) and stiffnesses (8, 14, 45, and 80 kPa) with a 4-9-MHz linear-array transducer. Targets were evaluated 10 times with three different methods-shear-wave elastography, strain ratio, and strain histogram analysis-yielding 600 evaluations. AUCs were calculated for data divided between different stiffnesses. A 1.5-6-MHz curved-array transducer was used to assess the effect of depth (3.5 vs 6 cm) on shear-wave elastography in 80 scans. Mixed model analysis was performed to assess the effect of target diameter and depth. RESULTS. Strain ratio and strain histogram AUCs were higher than the shear-wave velocity AUC (p < 0.001) in data divided as 80 versus 45, 14, and 8 kPa. In data divided as 80 and 45 versus 14 and 8 kPa, the methods were equal (p = 0.959 and p = 1.000, respectively). Strain ratios were superior (p = 0.030), whereas strain histograms were not significantly better (p = 0.083) than shear-wave elastography in data divided as 80, 45, and 14 versus 8 kPa. Target diameter had an effect on all three methods (p = 0.001). Depth had an effect on shear-wave velocity (p = 0.001). CONCLUSION. The ability to discern different target stiffnesses varies between shear-wave and strain elastography. Target diameter affected all methods. Shear-wave elastography is affected by target depth.

Ultrasound elastography for evaluation of cervical lymph nodes

Ultrasound (US) elastography has been introduced as a noninvasive imaging technique for evaluating cervical lymph nodes. US elastography techniques include strain elastography and shear wave-based elastography. The application of this technique is based on the fact that stiff tissues tend to deform less and show less strain than compliant tissues when the same force is applied. In general, metastatic lymph nodes demonstrate higher stiffness than benign lymph nodes. Overall, preliminary studies suggest that US elastography may be useful in differentiating benign and malignant cervical lymph nodes, thereby informing decisions to perform a biopsy and facilitating follow-up. For US elastography to be accepted into clinical practice, however, its techniques, associated diagnostic criteria, and reliability need to be further refined.

Differentiation of metastatic cervical lymph nodes with ultrasound elastography by virtual touch tissue imaging: preliminary study

OBJECTIVES

The purpose of this study was to investigate the clinical usefulness of acoustic radiation force impulse elastography for the differential diagnosis of cervical lymph nodes.

METHODS

Virtual touch tissue imaging (Siemens Medical Solutions, Mountain View, CA) was analyzed in 81 patients (mean age, 46.6 years; range, 5-82 years) with 81 lymph nodes (45 metastatic nodes and 36 benign nodes).

RESULTS

Most benign lymph nodes were slightly darker or the same in brightness compared with surrounding tissue, whereas most metastatic nodes were obviously darker. The mean area ratio of benign lymph nodes ± SD (1.05 ± 0.15) was statistically lower than the mean area ratio of metastatic lymph nodes (1.39 ± 0.20; P < 0.001). The area ration cutoff level for metastatic lymph nodes was estimated to be 1.16. With the use of a receiver operating characteristic curve with this cutoff value, the area ratio predicted malignancy with sensitivity of 91.1%, specificity of 83.3%, and an area under the curve of 0.925.

CONCLUSIONS

Acoustic radiation force impulse imaging is feasible for cervical lymph nodes. The Virtual Touch tissue imaging technique can complement conventional sonography, thereby making it easier to diagnose cervical lymph nodes.