Intra- and interobserver agreement among bronchial endosonographers for the description of intrathoracic lymph nodes

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 Multimodal Imaging for the Diagnosis of Intrathoracic Lymph Nodes

BACKGROUND

Endobronchial ultrasound (EBUS) imaging is valuable in diagnosing intrathoracic lymph nodes (LNs), but there has been little analysis of multimodal imaging. This study aimed to comprehensively compare the diagnostic performance of single and multimodal combinations of EBUS imaging in differentiating benign and malignant intrathoracic LNs.

METHODS

Subjects from July 2018 to June 2019 were consecutively enrolled in the model group and July 2019 to August 2019 in the validation group. Sonographic features of three EBUS modes were analysed in the model group for the identification of malignant LNs from benign LNs. The validation group was used to verify the diagnostic efficiency of single and multimodal diagnostic methods built in the model group.

RESULTS

373 LNs (215 malignant and 158 benign) from 335 subjects and 138 LNs (79 malignant and 59 benign) from 116 subjects were analysed in the model and validation groups, respectively. For single mode, elastography had the best diagnostic value, followed by grayscale and Doppler. The corresponding accuracies in the validation group were 83.3%, 76.8%, and 71.0%, respectively. Grayscale with elastography had the best diagnostic efficiency of multimodal methods. When at least two of the three features (absence of central hilar structure, heterogeneity, and qualitative elastography score 4-5) were positive, the sensitivity, specificity, and accuracy in the validation group were 88.6%, 78.0%, and 84.1%, respectively.

CONCLUSIONS

In both model and validation groups, elastography performed the best in single EBUS modes, as well as grayscale combined with elastography in multimodal imaging. Elastography alone or combined with grayscale are feasible to help predict intrathoracic benign and malignant LNs.

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.

Diagnostic value of radial endobronchial ultrasonographic features in predominant solid peripheral pulmonary lesions

Background

Transbronchial lung biopsy (TBLB) of peripheral pulmonary lesions (PPLs) is usually performed for a definite diagnosis. Radial probe endobronchial ultrasonography is often acknowledged as a good guidance method for TBLB as it can help physicians confirm the lesions’ position. It is also a non-invasive imaging diagnostic method. This clinical study was designed to evaluate the ability of radial endobronchial ultrasonography (R-EBUS) to differentiate benign from malignant predominant solid PPLs based on imaging features.

Methods

Patients with predominant solid PPLs were enrolled in this study retrospectively. TBLB was performed using R-EBUS with or without other guidance techniques. One typical sonographic image and one video of each lesion were recorded for analysis. Six radial probe endobronchial ultrasonographic image features (size, shape, echogenicity, margin, blood vessel, and linear-discrete air bronchogram) were studied by ultrasonography specialists and physicians who were blinded to the final diagnosis. The sum score model of the combined predictive factors indicated the best diagnostic accuracies for predicting malignant PPLs. The model group results were used to establish the diagnostic standard for a verification group.

Results

A total of 303 patients were enrolled in the model group from July 2018 to July 2019 at the Shanghai Chest Hospital (214 with malignant and 89 with benign lesions). The mean lesion long axis on computed tomographic images was 34.39±13.79 mm. There were significant statistical differences between benign and malignant lesions in the long axis, short axis, shape, margin, blood vessel, and linear-discrete air bronchogram assessed by radial endobronchial ultrasound. Long axis, lobulation, distinct but not sharp margin, absence of blood vessel, and absence of linear-discrete air bronchogram were good predictive factors of malignant lesions. A sum score model value of 79.54% of these combined factors indicated the best diagnostic accuracy for predicting malignant lesions. Eighty-seven patients were enrolled in the verification group from August to October 2019. The sum score model showed a diagnostic accuracy of 82.76%.

Conclusions

Radial endobronchial ultrasonographic features can differentiate malignant from benign lesions and thus have potential diagnosis value in predominant solid PPLs.

Endoscopic ultrasound-guided-fine-needle aspiration/fine-needle biopsy in diagnosis of mediastinal lymphadenopathy - A boon

Background/Objectives:

Evaluation of mediastinal lymphadenopathy (MLA) is a great diagnostic challenge considering the myriad of causes. In recent years, the role of endoscopic ultrasound (EUS) has been greatly extended in evaluation of MLA due to its safety, reliability, and accuracy. The present study details the role of EUS-guided-fine-needle aspiration/fine-needle biopsy (EUS-FNA/FNB) in MLA of unknown origin.

Methods:

Seventy-two patients (34 men) with MLA of unknown etiology were studied. Mediastinum was evaluated with linear echoendoscope and FNA/FNB was performed with 22-G needle and sent for cytology, histopathological, and mycobacterial growth indicator tube/GeneXpert evaluation. EUS-FNA/FNB diagnosis was based on cytology reporting by pathologists. Patients tolerated the procedure, and insertion of needle into the lesion was always successful without any complications.

Results:

EUS-FNA/FNB established a tissue diagnosis in 66/72 patients in first sitting, while six patients underwent repeat procedure. EUS-FNA diagnoses (after second sitting) were tuberculous lymphadenitis in 45/72 (62.5%), metastatic lymph nodes 12/72 (16.7%), reactive lymphadenopathy 6/72 (8.3%), sarcoidosis 4/72 (5.6%), and lymphoma 2/72 (2.8%), while it was nondiagnostic in 3/72 (4.1%) patients. Final diagnosis was based on combined clinical presentation, EUS-FNA/FNB result and clinicoradiological response to treatment on long-term follow-up of 6 months.

Conclusion:

EUS echo features along with EUS-FNA/FNB can diagnose MLA and surgical biopsy can be avoided.

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.

Endobronchial Ultrasound Elastography for Diagnosing Mediastinal and Hilar Lymph Nodes

BACKGROUND

Pathophysiological processes, such as malignancy, can lead to the formation of stiffer tissue in lung cancers. Endobronchial ultrasound (EBUS) elastography is a novel technique for measuring tissue stiffness during EBUS-guided transbronchial needle aspiration (EBUS-TBNA). The current study was conducted to investigate the diagnostic value of EBUS elastography for mediastinal and hilar lymph node metastasis in lung cancers.

METHODS

From January 2014 to January 2015, 40 patients suspected of lung cancer were enrolled, and a total of 68 lymph nodes were evaluated by EBUS-TBNA. EBUS-guided elastography of lymph nodes was performed prior to EBUS-TBNA. Standard EBUS characteristics were also described. Pathological determination of malignant or benign lymph nodes was used as the gold standard for this study. If EBUS-TBNA did not result in a formal pathological diagnosis of malignancy, patients were referred for a surgical procedure. Comparisons of elastography and standard EBUS characteristics were made between benign and malignant lymph nodes.

RESULTS

Elastography grading scores and strain ratios showed significant differences between benign and malignant lymph nodes (P = 0.000). The elastography strain ratio was more sensitive and specific for determining malignant lymph nodes than elastography grading score or standard EBUS criteria. The receiver operating characteristic curve for the elastography strain ratio showed an area under the curve of 0.933. The best cut-off point of the strain ratio for differentiating malignant from benign lymph nodes was 32.07. The elastography strain ratio had a sensitivity of 88.1%, the specificity of 80.8%, positive predictive value of 88.1%, and negative predictive value of 80.8% for distinguishing malignant from benign nodes. The overall accuracy of elastography strain ratio was 85.3%. The strain ratio of malignant and benign lymph nodes positively correlated with the elastography grading score (r = 0.561, P = 0.000).

CONCLUSIONS

EBUS elastography can be effectively used to predict mediastinal and hilar lymph node metastases in lung cancer. This noninvasive technique may thus complement standard EBUS and help guide EBUS-TBNA procedures.

Endoscopic ultrasound in mediastinal tuberculosis

Background:

Tubercular lymphadenitis is the commonest extra pulmonary manifestation in cervical and mediastinal locations. Normal characteristics of lymph nodes (LN) have been described on ultrasonography as well as by Endoscopic Ultrasound. Many ultrasonic features have been described for evaluation of mediastinal lymph nodes. The inter and intraobserver agreement of the endosonographic features have not been uniformly established.

Methods and Results:

A total of 266 patients underwent endoscopic ultrasound guided fine needle aspiration and 134 cases were diagnosed as mediastinal tuberculosis. The endoscopic ultrasound location and features of these lymph nodes are described.

Conclusion:

Our series demonstrates the utility of endoscopic ultrasound guided fine needle aspiration as the investigation of choice for diagnosis of mediastinal tuberculosis and also describes various endoscopic ultrasound features of such nodes.

EUS-derived criteria for distinguishing benign from malignant metastatic solid hepatic masses

BACKGROUND

Detection of hepatic metastases during EUS is an important component of tumor staging.

OBJECTIVE

To describe our experience with EUS-guided FNA (EUS-FNA) of solid hepatic masses and derive and validate criteria to help distinguish between benign and malignant hepatic masses.

DESIGN

Retrospective study, survey.

SETTING

Single, tertiary-care referral center.

PATIENTS

Medical records were reviewed for all patients undergoing EUS-FNA of solid hepatic masses over a 12-year period.

INTERVENTIONS

EUS-FNA of solid hepatic masses.

MAIN OUTCOME MEASUREMENTS

Masses were deemed benign or malignant according to predetermined criteria. EUS images from 200 patients were used to create derivation and validation cohorts of 100 cases each, matched by cytopathologic diagnosis. Ten expert endosonographers blindly rated 15 initial endosonographic features of each of the 100 images in the derivation cohort. These data were used to derive an EUS scoring system that was then validated by using the validation cohort by the expert endosonographer with the highest diagnostic accuracy.

RESULTS

A total of 332 patients underwent EUS-FNA of a hepatic mass. Interobserver agreement regarding the initial endosonographic features among the expert endosonographers was fair to moderate, with a mean diagnostic accuracy of 73% (standard deviation 5.6). A scoring system incorporating 7 EUS features was developed to distinguish benign from malignant hepatic masses by using the derivation cohort with an area under the receiver operating curve (AUC) of 0.92; when applied to the validation cohort, performance was similar (AUC 0.86). The combined positive predictive value of both cohorts was 88%.

LIMITATIONS

Single center, retrospective, only one expert endosonographer deriving and validating the EUS criteria.

CONCLUSION

An EUS scoring system was developed that helps distinguish benign from malignant hepatic masses. Further study is required to determine the impact of these EUS criteria among endosonographers of all experience.

The sonographic features of malignant mediastinal lymph nodes and a proposal for an algorithmic approach for sampling during endobronchial ultrasound

INTRODUCTION

There are several papers on the sonographic features of mediastinal lymph nodes affected by several diseases, but none gives the importance and clinical utility of the features.

OBJECTIVE

In order to find out which lymph node should be sampled in a particular nodal station during endobronchial ultrasound, we investigated the diagnostic performances of certain sonographic features and proposed an algorithmic approach.

METHODS

We retrospectively analyzed 1051 lymph nodes and randomly assigned them into a preliminary experimental and a secondary study group. The diagnostic performances of the sonographic features (gray scale, echogeneity, shape, size, margin, presence of necrosis, presence of calcification and absence of central hilar structure) were calculated, and an algorithm for lymph node sampling was obtained with decision tree analysis in the experimental group. Later, a modified algorithm was applied to the patients in the study group to give the accuracy.

RESULTS

The demographic characteristics of the patients were not statistically significant between the primary and the secondary groups. All of the features were discriminative between malignant and benign diseases. The modified algorithm sensitivity, specificity, and positive and negative predictive values and diagnostic accuracy for detecting metastatic lymph nodes were 100%, 51.2%, 50.6%, 100% and 67.5%, respectively.

CONCLUSIONS

In this retrospective analysis, the standardized sonographic classification system and the proposed algorithm performed well in choosing the node that should be sampled in a particular station during endobronchial ultrasound.

Initial experience with real-time elastography using an ultrasound bronchoscope for the evaluation of mediastinal lymph nodes

Real-time elastography performed during endoscopic ultrasonography is a relatively new method for characterizing tissue stiffness, and has been used successfully as a predictor of malignancy in mediastinal lymph nodes. This case report describes our practical experience with this technique using an ultrasound bronchoscope to examine mediastinal lymph nodes. We present a case of sectorial endobronchial ultrasound and the first published case of endoscopic ultrasound elastography using ultrasound bronchoscope in two patients with non-small cell lung carcinoma. Qualitative tissue color pattern was obtained in both cases and correlated with pathological evaluation. The initial feasibility results are promising and suggest that ultrasound bronchoscopy techniques, such as guided nodal staging, merit additional studies. It may be important to categorize the risk of malignancy to facilitate sampling decisions.

Fractal dimension analysis of malignant and benign endobronchial ultrasound nodes

Background

Endobronchial ultrasonography (EBUS) has been applied as a routine procedure for the diagnostic of hiliar and mediastinal nodes. The authors assessed the relationship between the echographic appearance of mediastinal nodes, based on endobronchial ultrasound images, and the likelihood of malignancy.

Methods

The images of twelve malignant and eleven benign nodes were evaluated. A previous processing method was applied to improve the quality of the images and to enhance the details. Texture and morphology parameters analyzed were: the image texture of the echographies and a fractal dimension that expressed the relationship between area and perimeter of the structures that appear in the image, and characterizes the convoluted inner structure of the hiliar and mediastinal nodes.

Results

Processed images showed that relationship between log perimeter and log area of hilar nodes was lineal (i.e. perimeter vs. area follow a power law). Fractal dimension was lower in the malignant nodes compared with non-malignant nodes (1.47(0.09), 1.53(0.10) mean(SD), Mann–Whitney U test p < 0.05)).

Conclusion

Fractal dimension of ultrasonographic images of mediastinal nodes obtained through endobronchial ultrasound differ in malignant nodes from non-malignant. This parameter could differentiate malignat and non-malignat mediastinic and hiliar nodes.