Diagnostic value of endobronchial ultrasound elastography for the differentiation of benign and malignant intrathoracic lymph nodes

Clinical utility of artificial intelligence-augmented endobronchial ultrasound elastography in lymph node staging for lung cancer

Objective

Endobronchial ultrasound elastography produces a color map of mediastinal lymph nodes, with the color blue (level 60) indicating stiffness. Our pilot study demonstrated that predominantly blue lymph nodes, with a stiffness area ratio greater than 0.496, are likely malignant. This large-scale study aims to validate this stiffness area ratio compared with pathology.

Methods

This is a single-center prospective clinical trial where B-mode ultrasound and endobronchial ultrasound elastography lymph node images were collected from patients undergoing endobronchial ultrasound transbronchial needle aspiration for suspected or diagnosed non-small cell lung cancer. Images were fed to a trained deep neural network algorithm (NeuralSeg), which segmented the lymph nodes, identified the percent of lymph node area above the color blue threshold of level 60, and assigned a malignant label to lymph nodes with a stiffness area ratio above 0.496. Diagnostic statistics and receiver operating characteristic analyses were conducted. NeuralSeg predictions were compared with pathology.

Results

B-mode ultrasound and endobronchial ultrasound elastography lymph node images (n = 210) were collected from 124 enrolled patients. Only lymph nodes with conclusive pathology results (n = 187) were analyzed. NeuralSeg was able to predict 98 of 143 true negatives and 34 of 44 true positives, resulting in an overall accuracy of 70.59% (95% CI, 63.50-77.01), sensitivity of 43.04% (95% CI, 31.94-54.67), specificity of 90.74% (95% CI, 83.63-95.47), positive predictive value of 77.27% (95% CI, 64.13-86.60), negative predictive value of 68.53% (95% CI, 64.05-72.70), and area under the curve of 0.820 (95% CI, 0.758-0.883).

Conclusions

NeuralSeg was able to predict nodal malignancy based on endobronchial ultrasound elastography lymph node images with high area under the receiver operating characteristic curve and specificity. This technology should be refined further by testing its validity and applicability through a larger dataset in a multicenter trial.

Quantitative evaluation of endobronchial ultrasound elastography in the diagnosis of benign and malignant mediastinal and hilar lymph nodes

OBJECTIVE

To compare the diagnostic value of different quantitative methods of endobronchial ultrasound elastography in benign and malignant mediastinal and hilar lymph nodes.

METHODS

This retrospective study included patients who underwent endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for mediastinal and hilar lymph node enlargement in our hospital between January 2019 and August 2022. We compared different quantitative elastography parameters [red area ratio (RAR, lymph node red area/lymph node area), green area ratio (GAR, lymph node green area/lymph node area), blue area ratio (SAR, lymph node blue area/lymph node area), mixed area ratio (MAR, lymph node green area/lymph node area), blue-green lymph node area/lymph node area), strain rate ratio (SR), strain rate in the target lymph node (LPA), ratio of blue area to total lymph node area outside the center of the target lymph node (PAR), and average grey value (MGV)], in order to find the best quantitative evaluation method.

RESULTS

A total of 244 patients (346 lymph nodes) were included in this study. All quantitative elastography parameters were statistically significant for the differentiation of benign and malignant lesions except the average grey value of the target lymph nodes. The area under the receiver operating characteristic curve of SAR was 0.872 (95% confidence interval: 0.83-0.91), the cutoff value was 0.409, and the sensitivity, specificity, positive and negative predictive values were 85.4%, 78.0%, 80.4%, and 83.4%, respectively.

CONCLUSION

Compared with other types of quantitative analysis, SAR has a higher predictive significance for benign and malignant lymph nodes.

Quantitative analysis of endobronchial elastography combined with serum tumour markers of lung cancer in the diagnosis of benign and malignant mediastinal and hilar lymph nodes

Purpose: In malignant tumours, elastography and serum tumour markers have shown high diagnostic efficacy. Therefore, we aimed to quantitatively analyse the results of endobronchial elastography combined with serum tumour markers of lung cancer to accurately distinguish benign and malignant mediastinal and hilar lymph nodes. Methods: Data of patients who underwent endobronchial ultrasound-guided transbronchial needle aspiration for mediastinal lymph node enlargement in our hospital between January 2018 and August 2022 were retrospectively collected. The characteristics of quantitative elastography and serum tumour markers were evaluated. Results: We enrolled 197 patients (273 lymph nodes). In the differential diagnosis of benign and malignant mediastinal and hilar lymph nodes, the stiffness area ratio (SAR), strain ratio (SR), and strain rate in lymph nodes were significant, among which SAR had the highest diagnostic value (cut-off value, 0.409). The combination of the four tumour markers had a high diagnostic value (AUC, 0.886). Three types of quantitative elastography indices combined with serum tumour markers for lung cancer showed a higher diagnostic value (AUC, 0.930; sensitivity, 83.5%; specificity, 89.3%; positive predictive value, 88.1%; negative predictive value, 85%) (p < 0.05). In the differential diagnosis of pathological types of lung cancer, different quantitative elastography indicators and serum tumour markers for lung cancer have different diagnostic significance for the differential diagnosis of lung cancer pathological types. Conclusion: The quantitative analysis of endobronchial ultrasound elastography combined with tumour markers can improve the diagnosis rate of benign and malignant mediastinal and hilar lymph nodes, help guide the puncture of false negative lymph nodes, and reduce the misdiagnosis rate.

Associations of Real-Time Ultrasound and Strain and Shear Wave Elastography with Gastrointestinal Organs: A Systematic Review

Ultrasound elastography is gaining attention for its diagnostic potential across various medical fields, and its physical properties make it valuable in modern clinical medicine. However, its specific attributes, especially in the context of recent medical advancements, remain relatively unexplored. This study aimed to identify instrument-specific characteristics and applications of real-time ultrasound elastography, shear wave elastography, and strain elastography, particularly within gastroenterology. Following PRISMA guidelines, the study examined elastography articles on databases like PubMed, resulting in 78 included articles. Data on patient demographics, organ involvement, specificity, sensitivity, accuracy, positive predictive value, and negative predictive value were extracted. Statistical analysis involved SPSS version 21, with significance set at p < 0.05. The majority of patients were male (50.50%), with a mean age of 42.73 ± 4.41 years. Shear wave elastography was the most prevalent technique (48.7%), and liver investigations were predominant in gastroenterology (34.6%). Gastrointestinal applications showed higher sensitivity, positive predictive value, and negative predictive values (p < 0.05) but lower specificity (p < 0.05). Real-time ultrasound elastography exhibited increased specificity, accuracy, and predictive values (p < 0.05). Ultrasound elastography appears more accurate and effective in gastroenterological settings. Nonetheless, its performance depends on instrument-specific and operator-dependent factors. While promising, further studies are necessary to ascertain optimal utilization in both gastrointestinal and non-gastrointestinal conditions.

Guidelines for endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA): Joint Indian Chest Society (ICS)/Indian Association for Bronchology (IAB) recommendations

Over the past decade, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has become an indispensable tool in the diagnostic armamentarium of the pulmonologist. As the expertise with EBUS-TBNA has evolved and several innovations have occurred, the indications for its use have expanded. However, several aspects of EBUS-TBNA are still not standardized. Hence, evidence-based guidelines are needed to optimize the diagnostic yield and safety of EBUS-TBNA. For this purpose, a working group of experts from India was constituted. A detailed and systematic search was performed to extract relevant literature pertaining to various aspects of EBUS-TBNA. The modified GRADE system was used for evaluating the level of evidence and assigning the strength of recommendations. The final recommendations were framed with the consensus of the working group after several rounds of online discussions and a two-day in-person meeting. These guidelines provide evidence-based recommendations encompassing indications of EBUS-TBNA, pre-procedure evaluation, sedation and anesthesia, technical and procedural aspects, sample processing, EBUS-TBNA in special situations, and training for EBUS-TBNA.

Ultrasound-Based Radiomics Can Classify the Etiology of Cervical Lymphadenopathy: A Multi-Center Retrospective Study

Medical diagnostic imaging is essential for the differential diagnosis of cervical lymphadenopathy. Here we develop an ultrasound radiomics method for accurately differentiating cervical lymph node tuberculosis (LNTB), cervical lymphoma, reactive lymph node hyperplasia, and metastatic lymph nodes especially in the multi-operator, cross-machine, multicenter context. The inter-observer and intra-observer consistency of radiomics parameters from the region of interest were 0.8245 and 0.9228, respectively. The radiomics model showed good and repeatable diagnostic performance for multiple classification diagnosis of cervical lymphadenopathy, especially in LNTB (area under the curve, AUC: 0.673, 0.662, and 0.626) and cervical lymphoma (AUC: 0.623, 0.644, and 0.602) in the whole set, training set, and test set, respectively. However, the diagnostic performance of lymphadenopathy among skilled radiologists was varied (Kappa coefficient: 0.108, *p < 0.001). The diagnostic performance of radiomics is comparable and more reproducible compared with those of skilled radiologists. Our study offers a more comprehensive method for differentiating LNTB, cervical lymphoma, reactive lymph node hyperplasia, and metastatic LN.

Utility of Elastography for Differentiating Malignant and Benign Lymph Nodes During EBUS-TBNA: A Systematic Review and Meta-analysis

BACKGROUND

Ultrasound elastography noninvasively estimates tissue hardness. Studies have evaluated elastography for differentiating malignant from benign lymph nodes during endobronchial ultrasound-guided transbronchial needle aspiration. Several methods of performing elastography are described with variable diagnostic accuracy.

METHODS

The aim of this study was to evaluate endobronchial ultrasound-guided elastography in differentiating malignant from benign mediastinal lymphadenopathy. We performed a systematic search of the PubMed and Embase databases to extract the relevant studies. A diagnostic accuracy meta-analysis was carried out to calculate the pooled sensitivity and specificity [with 95% confidence intervals (CIs)], and positive and negative likelihood ratios of elastography.

RESULTS

After a systematic search, 20 studies (1600 patients, 2712 nodes) were selected. The pooled sensitivity and specificity of elastography were 0.90 (95% CI, 0.84-0.94) and 0.79 (95% CI, 0.73-0.84), respectively. The summary receiver operating curve demonstrated an area under the curve for elastography of 0.90 (0.88-0.93). The positive and negative likelihood ratios and the diagnostic odds ratio were 4.3 (95% CI, 3.3-5.5), 0.12 (95% CI, 0.07-0.20), and 35 (95% CI, 19-63), respectively. Of the most commonly described methods, the color classification method (type 3 malignant vs. type 1 benign) demonstrated the highest area under the curve of 0.91 (0.88-0.93). There was significant heterogeneity and publication bias. Subgroup analyses indicated no significant difference between the sensitivity and specificity of quantitative and qualitative elastography methods.

CONCLUSIONS

Ultrasound elastography is useful in differentiating malignant and benign lymph nodes during endobronchial ultrasound-guided transbronchial needle aspiration. However, elastography does not replace the requirement of lymph node aspiration.

Mediastinal tumours and pseudo-tumours: a comprehensive review with emphasis on multidisciplinary approach

The diagnosis of a mediastinal mass may be challenging for clinicians, since lesions arising within the mediastinum include a variety of disease entities, frequently requiring a multidisciplinary approach. Age and sex represent important information, which need to be integrated with imaging and laboratory findings. In addition, the location of the mediastinal lesion is fundamental; indeed, we propose to illustrate mediastinal diseases based on the compartment of origin. We consider that this structured approach may serve as hint to the diagnostic modalities and management of mediastinal diseases. In this review, we present primary mediastinal tumours in the evolving context of new diagnostic and therapeutic tools, with recently described entities, based on our own experience with >900 cases encountered in the past 10 years.

Given the mediastinal anatomical heterogeneity, the correct positioning of mediastinal lesions becomes primal, in order to first establish a clinical suspicion and then to assist in planning biopsy and surgical procedurehttps://bit.ly/3p0gsk3

Diagnostic value of endobronchial ultrasound elastography combined with rapid onsite cytological evaluation in endobronchial ultrasound-guided transbronchial needle aspiration

Background

Endobronchial ultrasound (EBUS) elastography has been used in EBUS-guided transbronchial needle aspiration (EBUS-TBNA) to identify malignant lymph nodes based on tissue stiffness. Rapid onsite cytological evaluation (ROSE) has been widely utilized for onsite evaluation of sample adequacy and for guiding sampling during EBUS-TBNA. The aim of this study was to investigate the diagnostic value of combined EBUS elastography and ROSE in evaluating mediastinal and hilar lymph node status.

Methods

Retrospective chart review was performed from December 2018 to September 2020. Patient demographics, EBUS elastography scores, and ROSE, pathologic, and clinical outcome data were collected. The EBUS elastography scores were classified as follows: Type 1, predominantly nonblue; Type 2, partially blue and partially nonblue; and Type 3, predominantly blue. A receiver operating characteristic curve was used to compare the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio for evaluation of malignant lymph nodes among the EBUS elastography, ROSE, and EBUS combined with ROSE groups.

Results

A total of 245 patients (345 lymph nodes) were included. The sensitivity and specificity of the EBUS elastography group for the diagnosis of malignant lymph nodes were 90.51% and 57.26%, respectively. The sensitivity and specificity in the ROSE group were 96.32% and 79.05%, respectively. The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of EBUS elastography combined with ROSE were 86.61%, 92.65%, 11.78, and 0.14, respectively, and the area under the curve was 0.942.

Conclusions

Combining EBUS elastography and ROSE significantly increased the diagnostic value of EBUS-TBNA in evaluating mediastinal and hilar lymph node status compared to each method alone.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01748-4.

Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration (EBUS-TBNA): Technical Updates and Pathological Yield

Since the endobronchial ultrasound bronchoscope was introduced to clinical practice, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has become the procedure of choice to sample hilar and mediastinal adenopathy. Multiple studies have been conducted in the last two decades to look at the different technical aspects of the procedure and their effects on the final cytopathological yield. In addition, newer modes of ultrasound scanning and newer tools with the potential to optimize the selection and sampling of the target lymph node have been introduced. These have the potential to reduce the number of passes, reduce the procedure time, and increase the diagnostic yield, especially in rare tumors and benign diseases. Herein, we review the latest updates related to the technical aspects of EBUS-TBNA and their effects on the final cytopathological yield in malignant and benign diseases.

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.

ERS International Congress 2020: highlights from the Clinical Techniques, Imaging and Endoscopy assembly

The European Respiratory Society congress in the year 2020, a year dominated by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, was the first virtual congress planned with an innovative and interactive congress programme upfront. It was a large, novel platform for scientific discussion and presentations of cutting-edge innovative developments. This article summarises a selection of the scientific highlights from the Clinical Techniques, Imaging and Endoscopy assembly (assembly 14). In addition to presentations on the important role of bronchoscopy, imaging and ultrasound techniques in the field of SARS-CoV-2 infection, novel diagnostic approaches and innovative therapeutic strategies in patients with lung cancer, interstitial lung disease, obstructive airway disorders and infectious diseases were discussed.

Diagnostic value of endobronchial ultrasound image features: A specialized review

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) technology is important in the diagnosis of intrathoracic benign and malignant lymph nodes (LNs). With the development of EBUS imaging technology, its role in noninvasive diagnosis, as a supplement to pathology diagnosis, has been given increasing attention in recent years. Many studies have explored qualitative and quantitative methods for the three EBUS modes, as well as a variety of multimodal analysis methods, to find the optimal method for the noninvasive diagnosis using EBUS for LNs. Here, we review and comment on the research methods and predictive diagnostic value, discuss the existing problems, and look ahead to the future application of EBUS imaging.

Endobronchial Ultrasound Elastography Combined With Computed Tomography in Differentiating Benign from Malignant Intrathoracic Lymph Nodes

Objective. This study was to combine endobronchial ultrasound elastography (UE) with computed tomography (CT) to identify benign and malignant thoracic lymph nodes (LNs) more objectively and accurately. Methods. A total of 42 patients with intrathoracic lymphadenopathy required for endobronchial ultrasound with real-time guided transbronchial needle aspiration (EBUS-TBNA) examination were enrolled. All patients were examined by enhanced chest CT, B-mode ultrasound, and endobronchial ultrasound (EBUS)-guided elastography before EBUS-TBNA. Each lymph node was assessed by describing the characteristics of CT image (short diameter, texture, shape, boundary, and mean CT value), B-mode ultrasound (short diameter, echo characteristic, shape, and boundary), and elastography (image type, grading score, strain rate, and blue area ratio). The pathological results were used as the gold standard. The characteristics were compared alone and in combination between benign and malignant LNs. Results. The blue area ratio of elastography combined with CT had better diagnostic value in differentiating benign and malignant LNs than elastography alone, with the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) being 92%, 96%, 80%, 94%, and 86% vs 81%, 77%, 93%, 97%, and 56%, respectively. Elastography combined with B-mode ultrasound and CT characteristics showed the highest diagnostic value. Accuracy, sensitivity, specificity, PPV, and NPV were all 100%. Conclusions. Endobronchial UE combined with CT and B-mode ultrasound imaging shows a greater diagnostic value in differentiating benign and malignant intrathoracic LNs than either imaging alone.

CT texture analysis of mediastinal lymphadenopathy: Combining with US-based elastographic parameter and discrimination between sarcoidosis and lymph node metastasis from small cell lung cancer

Objectives

To investigate the potential of computed tomography (CT)-based texture analysis and elastographic data provided by endobronchial ultrasonography (EBUS) for differentiating the mediastinal lymphadenopathy by sarcoidosis and small cell lung cancer (SCLC) metastasis.

Methods

Sixteen patients with sarcoidosis and 14 with SCLC were enrolled. On CT images showing the largest mediastinal lymph node, a fixed region of interest was drawn on the node, and texture features were automatically measured. Among the 30 patients, 19 (12 sarcoidosis and 7 SCLC) underwent endobronchial ultrasound transbronchial needle aspiration, and the fat-to-lesion strain ratio (FLR) was recorded. Texture features and FLRs were compared between the 2 patient groups. Logistic regression analysis was performed to evaluate the diagnostic accuracy of these measurements.

Results

Of the 31 texture features, the differences between 11 texture features of CT ROIs in the patients with sarcoidosis versus patients with SCLC were significant. Among them, the grey-level run length matrix with high gray-level run emphasis (GLRLM-HGRE) showed the greatest difference (P<0.01). Differences between FLRs were significant (P<0.05). Logistic regression analysis together with receiver operating characteristic curve analysis demonstrated that the FLR combined with the GLRLM-HGRE showed a high diagnostic accuracy (100% sensitivity, 92% specificity, 0.988 area under the curve) for discriminating between sarcoidosis and SCLC.

Conclusion

Texture analysis, particularly combined with the FLR, is useful for discriminating between mediastinal lymphadenopathy caused by sarcoidosis from that caused by metastasis from SCLC.

Endobronchial Ultrasound Elastography for Differentiating Benign and Malignant Lymph Nodes

BACKGROUND

Endobronchial ultrasound elastography that provides information on tissue stiffness may help distinguish malignant from benign mediastinal and hilar lymph nodes.

OBJECTIVES

In this prospective trial, we assessed the diagnostic value of elastographic images and the interobserver agreement in its evaluation.

METHOD

Elastographic images from 77 lymph nodes in 65 patients were reviewed by 3 pneumologists. The elastographic image was classified based on the predominant colour: predominantly green, intermediary, and predominantly blue. With 2 or 3 interobserver matches, the corresponding elastographic image was correlated with the pathological result obtained from endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and/or other invasive procedures.

RESULTS

All 3 reviewers had agreement in classifying elastographic images in 45% (35/77). Overall, the interobserver agreement among the 3 readers for classifying elastographic pattern was found to be moderate (Fleiss Kappa index = 0.519; 95% CI = [0.427; 0.611]). On cytological/histological evaluation, 55 lymph nodes were malignant and 22 were benign. In classifying "green" as benign and "blue" as malignant, the sensitivity and specificity were 71% (95% CI = [54%; 85%]) and 67% (95%-CI = [35%; 90%]), respectively.

CONCLUSIONS

Elastography will not replace invasive EBUS-TBNA due to a moderate interobserver agreement and insufficient sensitivity and specificity. However, elastography will, maybe, present an additional feature to identify malignant lymph nodes in the context of clinical, radiological, and cytological results.

Diagnostic utility of endobronchial ultrasound (EBUS) features in differentiating malignant and benign lymph nodes - A systematic review and meta-analysis

BACKGROUND

EBUS is being widely used today for echolocation of lymph nodes for FNAC. We present a systematic review and meta-analysis to assess the diagnostic accuracy of EBUS characteristics of lymph nodes in diagnosing malignancy.

METHODS

A systematic search of published literature was undertaken using databases like PubMed, Web of Science, Cochrane, Google Scholar and Researchgate. Those studies reporting any endobronchial ultrasonography features of malignant lymph nodes like size, margins, echogenicity, shape, central hilar structure (CHS), coagulation necrosis sign (CNS) or color power doppler index (CPDI) were included for review. Random effects model was used to calculate pooled sensitivity, specificity, positive and negative likelihood ratios (LR), and diagnostic odds ratio (DOR). The review protocol was registered with the International prospective register of systematic reviews (PROSPERO registration no. CRD42019117716).

RESULTS

992 articles were retrieved of which 542 articles were evaluated in detail and finally 29 articles met the inclusion criteria. All EBUS features except CPDI showed a statistically significant area under the SROC curve. CNS showed highest area under the SROC curve [0.81 (SE: 0.09)] with maximum pooled specificity [0.93, 95%CI: 0.92-0.94], maximum pooled LR+ [5.12, 95%CI: 2.56-10.2] and DOR [9.23, 95%CI 3.85-22.15]. Maximum sensitivity was seen for CHS 0.91 [95%CI: 0.90-0.92].

CONCLUSION

EBUS features have the potential to help in more precise location of a malignant lymph node thereby helping in increasing the diagnostic yield. However, high diagnostic accuracy of various EBUS features can currently only be said to supplement tissue diagnosis.

Quantitative analysis of endobronchial ultrasound elastography in computed tomography-negative mediastinal and hilar lymph nodes

Background

Endobronchial ultrasound (EBUS) elastography assists in the differentiation of benign and malignant lymph nodes (LNs) during transbronchial needle aspiration (TBNA). However, previous studies have not compared B‐mode sonographic images (BSIs) and EBUS elastography images (EEIs) with final pathological diagnoses in radiologically normal‐sized (computed tomography [CT]‐negative) LNs.

Methods

Consecutive patients with CT‐negative LNs, who received EBUS‐TBNA, were retrospectively reviewed. Images of BSIs and EEIs of each LN were stored and independently evaluated. EEIs were assessed by calculating the stiffness area ratio (SAR, blue/overall areas). The receiver operating characteristic curve was used to calculate the cutoff value for the SAR. Diagnostic test parameters were evaluated for each EBUS finding.

Results

A total of 132 patients (149 LNs) were enrolled, and the median SAR of malignant LNs was significantly higher than that of benign LNs (0.58 vs. 0.32, P < 0.001). At the SAR cutoff of 0.41, the sensitivity, specificity, positive predictive value, negative predictive value (NPV), and diagnostic accuracy rate (DAR) of elastography were 88.2%, 80.2%, 78.9%, 89.0%, and 83.9%, respectively. The logistic regression analysis showed that elastography was the strongest predictor of malignancy (odds ratio, 18.5; 95% confidence interval [CI]: 6.48–52.6; P < 0.001). The highest NPV (96.6%) was achieved with a combination of BSIs and EEIs.

Conclusions

EBUS elastography predicted malignant LNs with a high DAR and NPV in CT‐negative LNs. The NPV was highest when EEIs were combined with BSIs. Therefore, the combined evaluation of CT‐negative LNs using EEIs and BSIs may help bronchoscopists perform EBUS‐TBNA more efficiently.

Key points

Significant findings of the study

Endobronchial ultrasound elastography accurately predicted malignancy with a high diagnostic accuracy rate and negative predictive value in radiologically normal‐sized lymph nodes. The additional use of B‐mode sonographic features resulted in a higher negative predictive value.

What this study adds

Endobronchial ultrasound elastography can guide the accurate collection of specimens with transbronchial needle aspiration, even in radiologically normal‐sized lymph nodes. It can also readily distinguish benign and malignant lymph nodes, thus avoiding unnecessary punctures.

The role of endobronchial ultrasound-guided transbronchial needle aspiration in isolated intrathoracic lymphadenopathy in non-neoplastic patients: a common dilemma in clinical practice

Objective:

To determine the diagnostic yield of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in non-neoplastic patients with isolated intrathoracic lymphadenopathy (IL).

Methods:

This was a retrospective study of patients with isolated IL referred for EBUS-TBNA. We calculated the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of EBUS-TBNA in the diagnosis of granulomatous, reactive, and neoplastic lymphadenopathy. In cases of nonspecific granulomas, reactive lymphadenopathy, or inconclusive results, a definitive diagnosis was established by other diagnostic procedures or during a follow-up period of at least 18 months.

Results:

Among the 58 patients included in the study, EBUS-TBNA established a diagnosis of granulomatous disease in 22 (38%), reactive lymphadenopathy in 15 (26%), cancer in 8 (14%), and other diseases in 3 (5%). Results were inconclusive in 10 (17%), the diagnosis being established by other bronchoscopic procedures in 2 (20%) and by surgical procedures in 8 (80%). A final diagnosis of reactive lymphadenopathy was established in 12. Of those, 11 (92%) had their diagnosis confirmed during follow-up and 1 (8%) had their diagnosis confirmed by mediastinoscopy. In another 3, a final diagnosis of sarcoidosis or neoplasm was established. For the diagnosis of granulomatous disease, neoplasms, and reactive lymphadenopathy, EBUS-TBNA was found to have a sensitivity of 73%, 68%, and 92%, respectively; a specificity of 100%, 100%, and 93%, respectively; an accuracy of 86%, 93%, and 93%, respectively; a PPV of 100%, 100%, and 80%, respectively; and an NPV of 78%, 92%, and 98%, respectively.

Conclusions:

In non-neoplastic patients, granulomatous disease and reactive lymphadenopathy appear to be common causes of isolated IL. EBUS-TBNA shows promising results as a first-line minimally invasive diagnostic procedure. The results obtained by EBUS-TBNA can be optimized by examining clinical and radiological findings during follow-up or by comparison with the results obtained with other bronchoscopic methods.

The role of endobronchial ultrasonography elastography for predicting malignancy

Background

This study aims to investigate the role of endobronchial ultrasonography elastography in predicting malignancy.

Methods

Between January 2016 and December 2016, a total of 221 lymph nodes were biopsied using the endobronchial ultrasonography-guided transbronchial needle aspiration from 119 consecutive patients (69 males, 50 females; mean age 63.2±12.4 years; range, 16 to 86 years) were included. Lymph nodes were scored by elastography according to their colors in four categories before the procedure. The strain ratio was calculated based on the region of interest after three measurements.

Results

Of the patients, 93 were diagnosed with a malignancy through endobronchial ultrasonography-guided transbronchial needle aspiration biopsy. The mean lymph node score of benign versus malignant lesions was 2.2±1.0 and 3.2±1, respectively (p<0.001). There was a positive correlation between the lymph node scores and lymph node diameter, strain ratio, ≥3 of lymph node scoring, the sensitivity for malignancy was 79% and specificity was 60%. The mean strain ratio for malignant and benign lymph nodes was 22.2±30.1 and 5.2±1.7, respectively (p<0.001). With a cut-off value of ≥2.47 of strain ratio, the sensitivity for malignancy was 75% and specificity was 65%. The combined use of positron emission tomography and lymph node score or strain ratio yielded 80.4% and 61.2% sensitivity and 80% and 70.3% specificity for malignancy, respectively.

Conclusion

Endobronchial ultrasonography elastography is useful in predicting malignancy of the lymph nodes. When combined with positron emission tomography, specificity and positive predictive value for malignancy increase.

Diagnostic Value of Elastography and Endobronchial Ultrasound in the Study of Hilar and Mediastinal Lymph Nodes

BACKGROUND

The aim of this study was to explore elastography features and its ability to distinguish between benign and malignant lymph nodes by comparing the results with an anatomopathologic examination used as gold standard.

METHODS

Patients were randomized in 2 groups [endobronchial ultrasound (EBUS) and EBUS-elastography]. Echographic characteristics of the lymph nodes were collected in both categories. In the EBUS-elastography group, elastographic data were also determined.

RESULTS

A total of 100 lymph nodes were evaluated. Group 1 (EBUS) consisted of 57 lymph nodes. Group 2 (EBUS-elastography) included 43 lymph nodes. In group 2, lymph nodes with predominantly blue pattern were associated with a pathologic determination of malignancy, and the probability of presenting malignant infiltration with this color pattern was 86.7% (P=0.00004). Malignant lymph nodes presented less color dispersion (48.8 vs. 94.8, P=0.00013), higher ratio of blue pixels (66% vs. 32.5%, P=0.016), and higher strain ratio (7.1 vs. 2.48, P=0.005). The cut-off points to distinguish between benign and malignant lymph nodes were 4 for strain ratio, 61 for frequency histograms, and 52 for blue pixel ratio. The area under the curve of the ROC curves were 0.75, 0.83, and 0.87, respectively. Group 2 presented a lower number of nondiagnostic samples (2.3% vs. 21%, P=0.001) and a higher rate of malignant results (42% vs. 16%, P=0.005).

CONCLUSION

EBUS-elastography is feasible during EBUS and may be helpful in predicting malignant lymph node infiltration. It could improve anatomopathologic sample collection and increase diagnostic efficiency.

Evaluating the use of elastography in endobronchial ultrasound technique as a diagnostic approach for mesothorax lymphadenopathy

Introduction: Non-small cell lung cancer is still diagnosed at a late stage although we have new diagnostic equipment such the radial endobronchial ultrasound, convex probe endobronchial ultrasound, and electromagnetic navigation. The diagnostic techniques have been upgraded with rapid on-site evaluation (ROSE) and currently from 2014 real-time elastography is being evaluated as a ROSE technique.Areas covered: A thorough search was performed on PubMed and Scopus with the following key words: elastography, strain ratio, convex probe EBUS, endoscopic ultrasound (EUS), elastography. In the current mini review, we will focus on published data regarding elastography with the convex probe endobronchial ultrasound in two different systems and comment on this future ROSE technique. Elastography, strain ratio, and factors such as(I) margin (indistinct or distinct); (II) shape (oval or round); (III) short-axis size less or more than 1 cm; (IV) presence or absence of central hilar structure (CHS); (V) echogenicity (homogeneous or heterogeneous); and (VI) presence or absence of coagulation necrosis sign are presented in our review based on published literature.Expert opinion: Current data indicate that we can have up to 93% sensitivity and specificity of real-time elastography and strain ratio for the evaluation of benignancy and malignancy; however, sample biopsy is still necessary. For now, we can only reduce the number of punctures.

The combination of endobronchial elastography and sonographic findings during endobronchial ultrasound-guided transbronchial needle aspiration for predicting nodal metastasis

Background

During endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA), the sonographic findings of B‐mode imaging, as well as endobronchial elastography, can be obtained noninvasively and used for the prediction of nodal metastasis.

Methods

Patients with lung cancer or suspected lung cancer who underwent EBUS‐TBNA were recorded prospectively and reviewed retrospectively. Both the B‐mode sonographic and elastographic findings were independently evaluated for each lymph node. The sonographic features were classified according to previously published criteria. If oval shape, indistinct margins, homogenous echogenicity, and the absence of coagulation necrosis sign were all observed by B‐mode imaging, then the lymph node was judged to be benign by sonographic imaging. In addition, if the stiffer area comprised more than 31% of the entire lymph node area, then the lymph node was judged to be malignant by elastography. We compared the results of these imaging‐based predictions with the pathological diagnoses.

Results

The prevalence of nodal metastasis was 78/228 (34.2%). B‐mode sonography predicted 95.8% of benign lymph nodes, and elastography predicted 72.1% of malignant lymph nodes. By combining the two modalities, 59 of 71 (83.1%) lymph nodes judged as malignant by both analyses were pathologically proven to be malignant, and 101 of 105 (96.2%) lymph nodes judged as benign by both analyses were pathologically proven to be benign.

Conclusion

The combination of elastography and sonographic findings showed good sensitivity and a high negative predictive value, which may facilitate selecting the most suspicious lymph nodes for biopsy.

Key points

Significant findings of the study.

The combination of endobronchial elastography and sonography resulted in a higher diagnostic yield than either modality alone for predicting benign and malignant lymph nodes in patients with lung cancer.

What this study adds.

The combination of endobronchial elastography and sonography will help clinicians identify the most suspicious lymph nodes for puncturing during EBUS‐TBNA, which may improve the efficiency of EBUS‐TBNA.

Endobronchial ultrasound elastography for diagnosing mediastinal and hilar lymph nodes

INTRODUCTION

The main objective was to analyze the technical variability of EBUS-elastography in the differentiation of benign and malignant hilar and mediastinal lymph nodes. As a secondary objective, the results of the EBUS-elastography in said differentiation were analyzed, comparing them with the anatomopathological results.

MATERIAL AND METHODS

Prospective and analytical study of lymph nodes in which EBUS-elastography was performed. Elastographic variables and their variability were analyzed.

RESULTS

24 patients and 38 lymph nodes were evaluated. Of these, 60.5% had a history of neoplasia, 71% of them were EBUS-elastography with diagnostic intention, 53% were mediastinal staging of lung cancer. Both procedures were performed in 25% of the patients. Lymph nodes were classified into elastographic colour patterns, red being characteristic of elastic tissues and blue of rigid tissues. The lymphadenopathies with apredominantly blue pattern were associated with an anatomopathological result of malignancy (86% vs. 14%, OR 20.4 (3.1 -245.1) p-value = .00015). Malignant lymph nodes presented less colour dispersion in the frequency histograms and a higher ratio of blue pixels and higher strain ratio. These variables showed a variability of 8.7, 9.9 and 31.6% respectively in repetitions in the same adenopathy. Finally, a 66% of consistency was obtained in the event of colour pattern variability (p .0000).

CONCLUSIONS

EBUS-elastography is feasible during EBUS and may be helpful in predicting malignant lymph node infiltration. The quantitative elastographic data show low variability in repetitions in the same adenopathy. The strain ratio is the most variable elastographic parameter.

Endobronchial ultrasound-guided transbronchial needle aspiration in sarcoidosis: Beyond the diagnostic yield

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the commonly used technique for pathological confirmation of clinically suspected sarcoidosis, mostly owing to its consistently high success rate in the detection of granulomas. However, other possible advantages, which are less appreciated and often poorly studied, may also contribute to the wider use of EBUS-TBNA in the future. These advantages include refinement of differential diagnoses through the study of lymph node characteristics during B-mode examination; reduction of complications associated with bronchoscopy, as well as improved triage of the specimen for ancillary studies with the use of rapid on-site evaluation; optimization of the quality of the sample through the selection of a target area for biopsy with minimal vascularity and absence of calcifications by using the colour Doppler and the B-mode; and prediction of the presence of extensive lymph node fibrosis by using the strain elastography module. Yet, limitations and possible clinical drawbacks should also be acknowledged. Indeed, due to the lack of specificity of the pathology findings in EBUS-derived samples, the diagnosis of sarcoidosis is one of the exclusion and should remain essentially clinical. The external validity of EBUS-TBNA results in sarcoidosis is questionable, as they mainly derive from studies in populations with a high disease prevalence. Finally, the risk exists that the low morbidity and high diagnostic yield of EBUS-TBNA may lead to its overuse in patients with clinical/radiological findings specific enough to secure a clinical diagnosis of sarcoidosis.

Endobronchial ultrasound elastography in mediastinal lymphadenopathy: Report of two cases and systematic review of literature

Endobronchial ultrasound elastography is new ultrasound technology that is being reported recently for the evaluation of mediastinal lymphadenopathy during endobronchial ultrasound-guided (EBUS) transbronchial needle aspiration. This modality is based on the assessment of tissue stiffness that may be useful in differentiating benign from malignant lesions. Image generation leads to colored images with different colors signifying varying degrees of stiffness. The utility of this technique has been studied to differentiate between benign and malignant lymph nodes and various methods for representation of results which include visual color estimation, quantitative color estimation, and strain ratios have been described. Herein, we report two patients with mediastinal lymphadenopathy wherein EBUS elastography was employed. We also systemically review the studies describing this technique in differentiating benign from malignant lymph nodes.

Optimal Endobronchial Ultrasound Strain Elastography Assessment Strategy: An Explorative Study

BACKGROUND

In lung cancer staging, mediastinal lymph nodes are currently aspirated using endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) based on size and FDG-PET avidity. EBUS strain elastography (SE) is a new technique that may help predict the presence of malignancy. However, a standardized assessment strategy for EBUS-SE measurement is lacking.

OBJECTIVES

The aim of this study was to determine the optimal assessment strategy for investigating the predictive value of EBUS-SE in mediastinal lymph nodes.

METHODS

Two qualitative visual analogue scale strain scores and two semiquantitative strain elastography measurements (a strain histogram and strain ratio) were acquired in 120 lymph nodes of 63 patients with (suspected) lung cancer. The dataset was randomized into an 80% training dataset to determine cut-off values. Performance was consecutively tested on the remaining 20% and the overall dataset.

RESULTS

The semiquantitative mean histogram scoring strategy with a cut-off value of 78 (range 0-255) showed the best and most reproducible performance in prediction of malignancy with 93% overall sensitivity, 75% specificity, 69% positive predictive value, 95% negative predictive value, and 82% accuracy. Combining the EBUS-SE mean histogram scoring outcome with PET-CT information increased the post-test probability of disease in relevant clinical scenarios, having a positive test likelihood ratio of 4.16 (95% CI 2.98-8.13) and a negative test likelihood ratio of 0.14 (95% CI 0.04-2.81) in suspicious lymph nodes based on FDG-PET or CT imaging.

CONCLUSIONS

EBUS-SE can potentially help predict lymph node malignancy in patients with lung cancer. The best semiquantitative assessment method is the mean strain histogram technique.

Differentiating malignant and benign lymph nodes using endobronchial ultrasound elastography

BACKGROUND/PURPOSE

Endobronchial ultrasound (EBUS) elastography is a new technique that provides information on tissue compressibility during endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). The purposes of this study were to evaluate the utility of EBUS elastography in differentiating malignant and benign mediastinal lymph nodes (LNs) and to explore the factors that influence its accuracy.

METHODS

A retrospective chart review of patients who underwent EBUS-TBNA from October 2016 to July 2017 was performed. EBUS with conventional B-mode features and elastographic patterns were compared with the final pathology results or clinical follow-up. We used the following EBUS elastographic patterns for classification: type 1, predominantly non-blue (green, yellow and red); type 2, part blue, part non-blue; type 3, predominantly blue. The potential impacts of the characteristics of LNs, the underlying lung diseases and obtaining fibrotic components from EBUS-TBNA specimens were evaluated relative to the accuracy of EBUS elastography.

RESULTS

A total of 206 LNs from 94 patients were retrospectively evaluated. In classifying type 1 as 'benign' and type 3 as 'malignant,' the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy rate were 90.6, 82.6, 71.6, 94.7 and 85.2%, respectively. The EBUS elastographic patterns had higher diagnostic yields and negative predictive values than conventional B-mode features. Logistic regression analysis revealed that central necrosis was a factor that influenced the accuracy of elastography in malignant LNs. The fibrotic component within benign LNs could cause an incorrect elastographic pattern.

CONCLUSION

EBUS elastography is a valuable tool in discriminating benign and malignant mediastinal LNs.

Semi-quantitative Analysis of EBUS Elastography as a Feasible Approach in Diagnosing Mediastinal and Hilar Lymph Nodes of Lung Cancer Patients

This study aimed to semi-quantitatively evaluate the elastographic imaging color distribution of mediastinal and hilar lymph nodes (LNs), and explored its utility in helping define malignant and benign LNs for lung cancer patients. We prospectively collected patients who underwent preoperative mediastinal staging of suspected lung cancer by EBUS-TBNA. We analyzed the elastography color distribution of each LN and calculated the blue color proportion (BCP). The LN elastographic patterns were compared with the final EBUS-TBNA pathological results. A receiver operating characteristic (ROC) curve was constructed to evaluate the diagnostic value of BCP. We sampled and analyzed 79 LNs from 60 patients. The average BCP in malignant LNs was remarkably higher than that in benign LNs (57.1% versus 30.8%, P < 0.001). The area under the ROC curve (AUC) for the BCP was 0.86 (95% CI: 0.78–0.94). The best cutoff BCP for differentiating between benign and malignant LNs was determined as 36.7%. All the 16 LNs (20.3%) with a BCP lower than 27.9% were diagnosed as benign tissues. Our study suggests that elastography is a feasible technique that may safely help to predict LN metastasis during EBUS-TBNA. We found a clear BCP cutoff value to help define positive and negative LNs.

Improvement of diagnostic efficiency in distinguishing the benign and malignant thyroid nodules via conventional ultrasound combined with ultrasound contrast and elastography

We aimed to evaluate the diagnostic values of conventional ultrasound (US), ultrasound contrast (UC) and ultrasound elastography (UE) in distinguishing the benign and malignant thyroid nodules. A total of 100 patients with thyroid nodules receiving operative treatment were selected; they underwent the conventional US, UE and UC examinations before operation, respectively. The nodules received pathological examination after operation to distinguish benign from malignant lesions. The sensitivity, specificity and diagnostic accordance rate of each diagnostic method was evaluated by receiver operating characteristic (ROC) curve, and the area under the curve (AUC) of ROC was calculated. The manifestations of malignant thyroid nodules in conventional US examination were mostly the hypoecho, heterogeneous echo, irregular shape, unclear boundary, aspect ratio <1, microcalcification and irregular peripheral echo halo, and there were statistically significant differences compared with the benign nodules (P<0.05). UE showed that the differences between benign and malignant nodules in 2, 3 and 4 points were statistically significant (P<0.05). The manifestations of malignant nodules in UC were mostly the irregular shape, obscure boundary, no obvious enhancement, heterogeneous enhancement and visible perfusion defects, and there were statistically significant differences compared with the benign nodules (P<0.05). ROC curve showed that both sensitivity and specificity of UE and UC were superior to those of conventional US. AUC was the largest (AUC = 0.908) and the diagnostic value was the highest in the conventional US combined with UE and UC. Conventional US combined with elastography and UC can significantly improve the sensitivity, specificity and accuracy of diagnosis of benign and malignant thyroid nodules.