Preoperative Evaluation of Central Lymph Nodes in Papillary Thyroid Carcinoma Using High-Resolution Ultrasound and Shear-Wave Elastography

ABSTRACT

The aim of this study was to discuss the diagnostic value of high-resolution ultrasound and virtual touch tissue imaging quantification (VTIQ) for distinguishing metastatic and benign central lymph nodes (CLNs) in patients with papillary thyroid carcinoma. This retrospective study involved 86 pathologically proven benign lymph nodes (LNs) and 118 metastatic LNs in patients with papillary thyroid carcinoma. We analyzed the sonographic features of CLNs (size, shape, distribution, hilum, echogenicity, cystic change, calcification, vascularity, shear-wave velocity [SWV]). The prevalence of sonographic features and the SWV was compared between metastatic and benign CLNs. The size, shape, margin, distribution, presence of hilum, echogenicity, calcification, and vascularity were significantly different between benign and metastatic CLNs (P < 0.05 for all). The mean maximum SWV for malignant CLNs was 3.139 ± 0.408 m/s, whereas that of benign CLNs was 2.418 ± 0.369 m/s (P < 0.05). The cutoff point of the SWV for differentiating benign and malignant LNs was 2.675 m/s. Logistic regression analysis showed that round or irregular shape, aggregation or fusion, calcification, and VTIQ value greater than 2.675 m/s of CLNs were independent risk factors for malignancy, with an odds ratio of 5.77, 3.05, 3.23, and 62.85, respectively. High-resolution ultrasound and VTIQ can provide valuable information for distinguishing metastatic from benign CLNs.

Shear wave velocity measurements obtained in different regions are repeatable for presumed normal canine lymph nodes: A pilot study

Shear wave elastography (SWE) has been applied as a noninvasive method for predicting regional lymph node (LN) metastases in human and veterinary patients. However, published studies describing standardized protocols and repeatability of this technique are currently lacking. The objective of this prospective, pilot, observer agreement study was to determine whether different shear wave velocity (SWV) measurements obtained in different regions of presumed normal canine LNs would be repeatable. Two imagers consecutively performed shear wave elastography of submandibular, superficial inguinal, and popliteal LNs in 10, clinically healthy adult dogs. Ten elastograms of each LN were acquired by each imager. In each adequate elastogram, three regions of interest (ROIs) were placed in the softest and stiffest region of the LN. Additionally, one ROI was drawn covering the entire LN. In each ROI, mean, median, and maximum SWVs were calculated. Mean values for the mean, median, and maximum SWVs varied from 2.33 to 3.10 m/s, 2.32 to 3.10 m/s, and 2.61 to 4.09 m/s, respectively. Intra- and interobserver agreements were acceptable. Superficial inguinal LNs demonstrated the highest intra- and interobserver agreement, followed by the popliteal and the submandibular LNs, respectively. Using the different measurements (mean, median, or maximum SWVs) had no significant effect on the intra- and interobserver variability, neither did the region (softest, stiffest, or entire LN). Findings indicated that all evaluated measurements and regions could be used to obtain reliable elastography data of presumed normal canine LNs. Clinical trials in dogs with cancer are necessary to compare SWVs of metastatic LNs with the reported SWVs and evaluate whether various measurements and regions can also be used in metastatic LNs.

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

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

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.

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.

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

Rationale and objectives

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

Materials and methods

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

Results

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

Conclusion

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

SONOGRAPHIC FOLLOW-UP OF PATIENTS WITH DIFFERENTIATED THYROID CARCINOMA: A COMPARISON OF THE ULTRASOUND ELASTOGRAPHY, POWER DOPPLER ULTRASOUND, AND B-MODE ULTRASOUND FEATURES IN DETECTING MALIGNANT LYMPH NODES

Objective: The aim of this study was to assess and compare the diagnostic power of B-mode ultrasonography (US), power Doppler US (PD), and ultrasound elastography (USE) in detecting malignant lymph nodes (LNs) during follow-up of patients who were operated on for differentiated thyroid cancer (DTC). Methods: In this prospective study, a total of 103 cervical LNs having suspicious malignant features from 72 patients with DTC were examined using US, PD, and USE. USE scores were classified from 1 to 3 according to the presence of elasticity (1, soft; 2, intermediate; 3, hard). The strain ratios (SRs) of all LNs were calculated according to adjacent muscle tissue. Results: The most-sensitive ultrasonographic features were hilum loss and hypoechogenicity, with 94.4% and 80.6% sensitivity and 93.5% and 84.4% negative predictive value, respectively. The most-specific feature was the presence of cystic component, with 98.5% specificity and 85.7% positive predictive value. Presence of diffuse/chaotic or irregular vascularity in PD had 47.2% sensitivity and 83.6% specificity in predicting metastasis. In USE, the sensitivity and specificity of score 3 were 56.7% and 74.2%, respectively. The median SR of metastatic LNs was higher than that of benign LNs (median SR [min-max], 3.0 [0.16 and 29] vs. 1.89 [0.26 and 37.9]), but the difference was not significant (P = .07). Multivariate logistic regression analyses revealed 4.9-, 6.6-, and 10-fold increases in metastasis risk for short/long axis ratio ≥0.5, nodal vascularity, and score 3 USE, respectively (P<.05). Conclusion: While USE had higher sensitivity, PD had higher specificity in detecting malignant LNs, but none of these techniques was as sensitive and specific as gray-scale US features. Abbreviations: CI = confidence interval; DTC = differentiated thyroid cancer; LN = lymph node; LN-Tg = lymph node-thyroglobulin; NPV = negative predictive value; PD = power Doppler; PPV = positive predictive value; ROI = region of interest; SR = strain ratio; US = ultrasonography; USE = ultrasound elastography.

Virtual touch tissue imaging quantification shear wave elastography for determining benign versus malignant cervical lymph nodes: a comparison with conventional ultrasound

PURPOSE

We aimed to prospectively examine virtual touch tissue imaging quantification (VTIQ) shear wave elastography (SWE) and conventional (B-mode and Doppler) ultrasonography (US), individually and combined, for their ability to differentiate benign and malignant cervical lymph nodes (CLNs).

METHODS

One hundred enlarged lymph nodes (LNs) from 72 patients, confirmed by histopathologic diagnoses, were included in the present study. B-mode US, Doppler US, and SWE were performed before histopathologic sampling of the LNs. The LN shear wave velocity (SWV, m/s) was assessed by VTIQ.

RESULTS

Using a 3.03 m/s cutoff value, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of SWVmax for differentiating benign and malignant CLNs were 93%, 59%, 68%, 91%, and 75%, respectively. B-mode and Doppler had a sensitivity, specificity, PPV, NPV, and accuracy of 79.2%, 71.2%, 71.6%, 78.7%, and 75%, respectively. B-mode, Doppler, and VTIQ SWE combined had 87.5%, 75%, 76.3%, 86.6%, and 81% for the same parameters, respectively.

CONCLUSION

VTIQ SWE is a promising noninvasive diagnostic imaging technique for differentiating benign and malignant CLNs. VTIQ SWV can improve the diagnostic performance of conventional US for differentiating benign and malignant CLNs.

Diagnostic role of ultrasound elastography on lymph node metastases in patients with head and neck cancer

Introduction

Ultrasonography is the easiest non-invasive method to diagnose lymph node metastases in patients with head and neck cancer. However, since CT scans are often preferred in the evaluation of primary tumours of these patients, information about lymphatic metastases may also available in these patients. Therefore, ultrasound is not routinely employed in the evaluation of these patients. However, elastography technique, a recent development in ultrasound technology, could make use of ultrasonography in these patients even more widespread, even though it is still not widely used today.

Objectives

The aim of this study was to evaluate the role of sonographic elastography in the diagnosis of lymph node metastasis of head and neck cancer.

Methods

Twenty-three patients diagnosed with head and neck cancer and scheduled for surgical treatment including neck dissection were included in the study. All patients underwent neck examination by palpation, ultrasound elastography and computerized tomography with contrast. To compare the diagnostic performance of palpation, ultrasound elastography and computerized tomography, the findings of each examination method were compared with the histopathological examination results of neck specimens.

Results

15 (65.2%) patients had a primary tumour in the larynx; 7 (30.4%) in the oral cavity; and 1 (4.3%) in the parotid. 7 (30.4%) out of 23 patients underwent bilateral neck dissection. In total, 30 neck dissections were hereby taken into account during study. Ultrasound elastography showed higher accuracy (83.3%) and higher sensitivity (82.4%) than palpation and computerized tomography, but the specificity of ultrasound elastography was lower (84.6%) than palpation and computerized tomography.

Conclusions

Ultrasound elastography is helpful for the diagnosis of lymph node metastases in patients with head and neck cancer. Due to its non-invasive character, it can be used safety in combination with other radiological techniques to support or improve their diagnostic performance.

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.

Clinical value of the VTIQ technology in the differential diagnosis of superficially enlarged lymph nodes

Background Lymph node enlargement is a common clinical finding in clinical practice with different treatment strategies. Purpose To investigate the application of Virtual Touch Image Quantification (VTIQ) to diagnose benign and malignant superficial enlarged lymph nodes. Material and Methods Between December 2015 and August 2016, 116 superficial enlarged lymph nodes were examined by VTIQ. Maximum (V_max), minimum (V_min), and average (V_mean) shear wave velocities (SWV) were obtained from the lymph nodes and from normal muscular tissues (V_n) located at the same level and within 5 mm from the target lymph node. The pathological results were used as the gold standard to evaluate VTIQ. Results All 116 patients underwent fine-needle aspiration biopsy for pathological examination. Forty patients had malignant lymph nodes and 76 patients had benign lymph nodes. Lymph node characteristics on B-mode ultrasound showed no differences between malignant and benign lymph nodes, but there were differences in VTIQ parameters (all P < 0.001). Compared with pathological diagnosis as the gold standard, the area under the ROC curves of V_max, V_min, and V_mean were 0.815, 0.746, and 0.795. The V_max cutoff value to diagnose benign from malignant lymph nodes was 3.045 m/s. The sensitivity, specificity, and positive and negative predictive values were 70%, 78.9%, 63.6%, and 83.3%. Conclusion VTIQ has a clinical application in the differential diagnosis of superficial enlarged lymph nodes.

Preliminary Evaluation of Virtual Touch Tissue Imaging Quantification for Differential Diagnosis of Metastatic and Nonmetastatic Cervical Lymph Nodes

OBJECTIVES

Virtual Touch tissue imaging quantification (VTIQ; Siemens Medical Solutions, Mountain View, CA) is useful for assessing tissue hardness. This study aimed to investigate the value of VTIQ in differential diagnosis of cervical lymph nodes.

METHODS

We retrospectively analyzed conventional sonograms and VTIQ images of 85 pathologically confirmed patients with superficial lymph node lesions. Conventional sonography was first performed, with 2-dimensional images described. Then VTIQ shear wave velocity (SWV) values of superficial lymph nodes were measured. With pathologic diagnosis as the reference standard, a receiver operating characteristic curve was generated to evaluate VTIQ efficacy in differential diagnosis of metastatic and nonmetastatic cervical lymph nodes.

RESULTS

Of the 85 nodes, 44 and 41 were metastatic and nonmetastatic, respectively. The latter group included 24 and 17 hematologic/lymphatic system disease and reactive hyperplastic nodes, respectively. Shear wave velocity values of metastatic nodes were significantly higher than those of their nonmetastatic counterparts (P < .001). With an area under the curve (AUC) of 0.953 and SWV cutoff of 3.27 m/s, accuracy, sensitivity, and specificity were 89.4%, 88.6%, and 90.2%, respectively, for distinguishing metastatic and nonmetastatic nodes. An AUC of 0.943 and SWV cutoff of 3.23 m/s yielded accuracy, sensitivity, and specificity of 88.2%, 88.6%, and 87.5% for differentiating metastatic from hematologic/lymphatic system disease nodes. Finally, an AUC of 0.968 and SWV cutoff of 3.27 m/s yielded accuracy, sensitivity, and specificity of 90.2%, 88.6%, and 94.1% for differentiating metastatic from reactive hyperplastic nodes.

CONCLUSIONS

Virtual Touch tissue imaging quantification is efficient in differential diagnosis of metastatic and nonmetastatic cervical 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.