Value of contrast-enhanced ultrasonography in the differential diagnosis of enlarged lymph nodes: a meta-analysis of diagnostic accuracy studies

Development of a Novel Contrast-Enhanced Ultrasound-Based Nomogram for Superficial Lymphadenopathy Differentiation: Postvascular Phase Value

OBJECTIVE

The aim of this study was to develop and prospectively validate a prediction model for superficial lymphadenopathy differentiation using Sonazoid contrast-enhanced ultrasound (CEUS) combined with ultrasound (US) and clinical data.

METHODS

The training cohort comprised 260 retrospectively enrolled patients with 260 pathological lymph nodes imaged between January and December 2020. Two clinical US-CEUS models were created using multivariable logistic regression analysis and compared using receiver operating characteristic curve analysis: Model 1 included clinical and US characteristics; Model 2 included all confirmed predictors, including CEUS characteristics. Feature contributions were evaluated using the SHapley Additive exPlanations (SHAP) algorithm. Data from 172 patients were prospectively collected between January and May 2021 for model validation.

RESULTS

Age, tumor history, long-axis diameter of lymph node, blood flow distribution, echogenic hilus, and the mean postvascular phase intensity (MPI) were identified as independent predictors for malignant lymphadenopathy. The area under the curve (AUC), sensitivity, specificity, and accuracy of MPI alone was 0.858 (95% confidence interval [CI], 0.817-0.891), 86.47%, 74.55%, and 81.2%, respectively. Model 2 had an AUC of 0.919 (95% CI, 0.879-0.949) and good calibration in training and validation cohorts. The incorporation of MPI significantly enhanced diagnostic capability (p < 0.0001 and p = 0.002 for training and validation cohorts, respectively). Decision curve analysis indicated Model 2 as the superior diagnostic tool. SHAP analysis highlighted MPI as the most pivotal feature in the diagnostic process.

CONCLUSION

The employment of our straightforward prediction model has the potential to enhance clinical decision-making and mitigate the need for unwarranted biopsies.

Contrast-enhanced ultrasound-based nomogram for predicting malignant involvements among sonographically indeterminate/suspicious cervical lymph nodes in patients with differentiated thyroid carcinoma

This prospective study was aimed at assessing the value of nomograms based on conventional and contrast-enhanced ultrasound (CEUS) features in the pre-operative diagnosis of sonographically indeterminate/suspicious lymph node metastasis (LNM) in patients with differentiated thyroid carcinoma (DTC). A total of 72 cervical LNs from 47 patients with DTC from January to June 2018 were included in the primary data set, and 30 LNs from 15 patients with DTC from July to August 2018 were included in the external validation data set. The LNs of the included patients were preoperatively evaluated by conventional ultrasound (US) and CEUS. Each included LN was labeled by puncture localization with carbon nanoparticle suspension injection (Canalin) under US guidance and dissected separately to ensure the one-to-one correspondence between ultrasonic features and pathology status. Univariate logistic regression analysis was used to identify risk factors for LNM. A nomogram was used to construct a prediction model for cervical metastatic LNs. Round shape, absence of hilar structure, peripheral or mixed blood flow and centripetal or mass enhancement were risk factors for lymph node metastases. The area under the receiver operating characteristic curve of the nomogram model based on conventional US and CEUS features was 0.93 (95% confidence interval: 0.872-0.985), which was superior to that of the nomogram based on conventional US features(0.85, 95% confidence interval: 0.707-0.989). CEUS features can provide incremental benefit in the diagnosis of LNM among DTC cohorts. Nomograms based on conventional US and CEUS features can predict LN status with high accuracy.

Case Report: Primary Mediastinal Large B-Cell Lymphoma Invasion of Extranodal Thyroid Tissue Mimicking Tuberculosis and Confounded by Similar Ultrasonic Appearance

Background

Primary mediastinal large B-cell lymphoma (PMBCL) is a rare type of diffuse large B-cell lymphoma, which has significant features that overlap with those of Hodgkin’s lymphoma. Ultrasound is a commonly used modality to characterize superficial lymph no5des, and ultrasonic findings are often used to distinguish lymphoma from lymph node tuberculosis in daily clinical practice. Although a common malignancy, lymphoma rarely involves extranodal tissues.

Case Presentation

Here we report the case of a 42-year-old Chinese male patient with PMBCL who was misdiagnosed with tuberculosis because of extranodal invasion. He visited our hospital for a neck mass that he had been noting for 1 week. Ultrasound revealed multiple enlarged lymph nodes on both sides of the neck. The lesions appeared to involve the surrounding soft tissue and thyroid gland, resembling a tuberculous sinus tract formation. Cervical spine computed tomography showed no obvious abnormalities in the cervical cone or bone damage. Contrast-enhanced ultrasound indicated that one of the enlarged lymph nodes in the right neck was rich in blood supply and exhibited centripetal enhancement, with uniform high enhancement at the peak. The patient underwent two ultrasound-guided punctures; the first puncture was performed for an enlarged lymph node in the right neck at Hangzhou Red Cross Hospital. Hodgkin’s lymphoma was suspected based on pathological and immunohistochemical findings, whereas a rare type of diffuse large B-cell lymphoma was suspected at Zhejiang Cancer Hospital.

Conclusions

Lymphoma is often misdiagnosed, causing delayed treatment initiation and affecting patient outcomes as the disease progresses. The present case demonstrates that the ultrasonic appearance of lymphoma may sometimes be confused with that of tuberculosis. Although ultrasound-guided needle biopsy has a high diagnostic accuracy, it may also cause diagnostic deviation because of insufficient sampling volume. Moreover, owing to the enlargement of multiple lymph nodes due to lymphoma or lymph node tuberculosis, puncturing different lymph nodes may provide different results.

Logistic Regression Analysis of Conventional Ultrasound, and Contrast-Enhanced Ultrasound Characteristics: Is It Helpful in Differentiating Benign and Malignant Superficial Lymph Nodes?

OBJECTIVES

This study aimed to screen the significant sonographic features for differentiation of benign and malignant superficial lymph nodes (LNs) by logistic regression analysis and fit a model to diagnose LNs.

METHODS

A total of 204 pathological LNs were analyzed retrospectively. All the LNs underwent conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS) examinations. A total of 16 suspicious sonographic features were used to assess LNs. All variables that were statistically related to the diagnosis of LNs were included in the logistic regression analysis in order to ascertain the significant features of diagnosing LNs, and to establish a logistic regression analysis model.

RESULTS

The significant features in the logistic regression analysis model of diagnosing malignant LNs were absence of echogenic hilus, age, and absence of hilum after enhancement. According to the results of logistic regression analysis, the formula to predict whether LNs were malignant was established. The area under the receiver operating curve (ROC) was 0.908 and the accuracy, sensitivity, and specificity were 85.0%, 92.9%, and 85.3%, respectively.

CONCLUSION

The logistic regression model for the significant sonographic features of conventional US and CEUS is an effective and accurate diagnostic tool for differentiating malignant and benign LNs.

Endoscopic ultrasound assessment and tissue acquisition of mediastinal and abdominal lymph nodes

The differential diagnosis between benign and malignant lymph nodes (LNs) has a fundamental role in the characterization and staging of malignant conditions, as well as in subsequent patients’ management. All imaging modalities (i.e. computed tomography and magnetic resonance imaging) rely mainly on size; endoscopic ultrasound (EUS) criteria based on B-mode evaluation and Doppler features fail to adequately characterize with high specificity LNs nature. The introduction of EUS-elastography and contrast-enhanced harmonic EUS are useful techniques to increase the diagnostic yield in identifying metastatic LNs, to identify which suspicious LN should require pathological characterization and, finally, to target tissue acquisition. EUS-guided tissue acquisition (EUS-TA) is increasingly being used for diagnosing lymphadenopathy whenever the characterization modifies patients’ subsequent management and when no superficial LN is accessible. Since target therapy are currently available (i.e. lung cancer, breast cancer), EUS-TA of malignant LNs could be required to identify tumor biology. In this field, both fine needle aspiration and biopsy needles are able to guarantee accurate results with almost perfect specificity and sub-optimal sensitivity. We finally propose a diagnostic algorithm based on most recent, high-level evidence for the diagnostic approach to suspected LNs assessment.

Do medullary thyroid carcinoma patients with high calcitonin require bilateral neck lymph node clearance? A case report

BACKGROUND

In clinical work, 85%-90% of malignant thyroid diseases are papillary thyroid cancer (PTC); thus, clinicians neglect other types of thyroid cancer, such as medullary thyroid carcinoma (MTC).

CASE SUMMARY

We report a 53-year-old female patient with a preoperative calcitonin level of 345 pg/mL. There was no definitive diagnosis of MTC by preoperative fine-needle aspiration cytology or intraoperative frozen pathology, but the presence of PTC and MTC was confirmed by postoperative paraffin pathology. The patient underwent total thyroidectomy and bilateral central lymph node dissection. Close follow-up at 1.5 years after surgery revealed no signs of recurrence or metastasis.

CONCLUSION

The issue in clinical work-up regarding types of thyroid cancer provides a novel and challenging idea for the surgical treatment of MTC. In the absence of central lymph node metastasis, it is worth addressing whether patients with high calcitonin can undergo total thyroidectomy and bilateral central lymph node dissection without bilateral lateral neck lymph node dissection.

Clinical Utility of Contrast-enhanced Ultrasound for the Diagnosis of Lymphadenopathy

This meta-analysis aimed to evaluate the diagnostic accuracy of contrast-enhanced ultrasonography (CEUS) in identifying lymphazdenopathy. PubMed, Web of Science, Embase and the Cochrane Library were searched for relevant articles through September 2020. A total of 16 articles, which included 1787 participants, were analyzed. The summary sensitivity, specificity, positive likelihood ratio (LR), negative LR and diagnostic odds ratio of CEUS for diagnosing lymphadenopathy were 0.88 (0.86-0.90), 0.90 (0.88-0.92), 6.04 (3.67-9.95), 0.15 (0.10-0.21) and 47.38 (23.45-95.66), respectively. The summary receiver operating characteristic (SROC) area under the curve (AUC) was 0.9405. After omitting outliers identified in a bivariate box plot and forest plot, heterogeneity was decreased, and the pooled sensitivity and specificity were 0.87 (0.84-0.90) and 0.87 (0.84-0.90), respectively. Furthermore, the SROC AUC was 0.9327. In conclusion, CEUS has the potential to be a valuable tool for characterizing lymphadenopathy and could provide clinical decision support.

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.

Application of Contrast-Enhanced Ultrasound (CEUS) in Lymphomatous Lymph Nodes: A Comparison between PET/CT and Contrast-Enhanced CT

Purpose

We described imaging characteristics of different types of lymphomas using contrast-enhanced ultrasound (CEUS) and summarized some simple criteria to distinguish between normal lymph nodes and lymphomatous lymph nodes for clinical diagnosis.

Materials and methods

Sixty-one lymphoma patients from 2014 to 2015 with 140 suspicious lymph nodes, who had been confirmed by histology and underwent chemotherapy, were enrolled in our study. The responses to chemotherapy were recorded by PET/CT, contrast-enhanced CT, or CEUS.

Results

We summarized the CEUS enhancement patterns as two types when detecting lymphomatous lymph nodes, which could be the specific diagnostic criteria: (1) rapid well-distributed hyperenhancement, with 83.1% lesions exhibiting a fast-in hyperenhancement pattern in the arterial phase, and (2) rapid heterogeneous hyperenhancement, with 16.9% lesions exhibiting heterogeneous in the arterial phase. Particularly, we found that all the suspicious lesions of indolent lymphomas were rapid well-distributed hyperenhancement. CEUS successfully identified 117 lymphomatous lymph nodes, while PET/CT and contrast-enhanced CT detected 124 and 113 lymphomatous lymph nodes, respectively. CEUS had an accuracy of 83.57%, and the accuracy of PET/CT and contrast-enhanced CT was 88.57% and 80.71%, respectively (p=0.188). The false-negative rate was 16.43%, 11.43%, and 19.29%, respectively (p=0.188).

Conclusion

CEUS could be a useful tool in detecting lymphomatous nodes. A rapid well-distributed hyperenhancement pattern in CEUS could be a useful diagnostic criterion in both aggressive lymphoma and indolent lymphoma. These results can help us distinguish between lymphomatous and benign lymph nodes and make better diagnostic and therapeutic decisions.

Analysis of Contrast-Enhanced Ultrasound Perfusion Patterns and Time-Intensity Curves for Metastatic Lymph Nodes From Lung Cancer: Preliminary Results

OBJECTIVES

To retrospectively summarize the similarities and differences in contrast-enhanced ultrasound (US) findings for lymph node metastasis from adenocarcinoma, squamous carcinoma, and small cell lung cancer.

METHODS

Patients who had received contrast-enhanced US examinations and had a histologic diagnosis of supraclavicular lymph node metastasis from lung cancer were included. The perfusion patterns on contrast-enhanced US images and time-intensity curve parameters were analyzed for the different pathologic types. The microvascular density and microvascular diameter were evaluated.

RESULTS

Totally, 61 patients were enrolled in this study, including 26 cases with lung squamous carcinoma, 26 with lung adenocarcinoma, and 9 with small cell lung cancer. Contrast-enhanced US perfusion showed no significant differences in enhancement uniformity during the arterial phase and in the presence of unenhanced areas of metastatic lymph nodes with the 3 different pathologic origins (P > .05), but fewer unenhanced areas could be seen in metastatic lymph nodes from adenocarcinoma. The analysis of the time-intensity curve parameters showed that there were significant differences in the peak intensity between metastatic lymph nodes from lung squamous carcinoma and lung adenocarcinoma (P < .05). The microvascular density of metastatic lymph nodes from adenocarcinoma was significantly higher than that of metastatic lymph nodes from squamous carcinoma and small cell lung cancer (P < .001; P = .0444), whereas the microvascular diameter of metastatic lymph nodes from adenocarcinoma was significantly smaller than that from squamous carcinoma and small cell lung cancer (P = .0277; P < .001).

CONCLUSIONS

Effects of the pathologic diagnosis should be considered when analyzing quantitative parameters of metastatic lymph nodes during contrast-enhanced US examinations, even in the same organ.

Role of Contrast-Enhanced Ultrasound in the Pre-operative Diagnosis of Cervical Lymph Node Metastasis in Patients with Papillary Thyroid Carcinoma

The objective of this study was to prospectively evaluate the diagnostic accuracy of contrast-enhanced ultrasonography (CEUS) in differentiating between benign and metastatic cervical lymph nodes in patients with papillary thyroid cancer (PTC). Three hundred nineteen cervical lymph nodes (162 metastatic from PTC and 157 benign) were evaluated using conventional ultrasonography (US) and CEUS before biopsy or surgery. Metastatic lymph nodes more often manifested centripetal or asynchronous perfusion, hyper-enhancement, heterogeneous enhancement, perfusion defects and ring-enhancing margins than benign lymph nodes at pre-operative CEUS (all p values < 0.001). The area under the receiver operating characteristic curve (AUC) for the combination of conventional US and CEUS (0.983, 95% confidence interval [CI]: 0.971-0.994) was higher than that of conventional US alone (0.929, 95% CI: 0.899-0.958) and CEUS (0.911, 95% CI: 0.876-0.947). In conclusion, CEUS is a promising tool in conjunction with conventional US for the pre-operative prediction of metastatic cervical lymph nodes in patients with PTC.

Role of contrast-enhanced endoscopic ultrasound in lymph nodes

Diagnosing unclear lymph node (LN) enlargements in the mediastinum and abdomen is the most important indication of endoscopic ultrasound (EUS)-fine needle aspiration (FNA) after the diagnosis and treatment of pancreatic diseases. Investigating LNs in these areas can happen in different clinical settings. Mostly, it is the first modality in general LN diseases without any peripheral LN enlargements. On the other hand, it can be the question of LN involvement in a known or suspected primary tumor. Due to EUS-FNA cytology, those questions can be answered highly, accurately. However, a primary discrimination of LNs might be helpful to increase the diagnostic value of the FNA cytology, especially in cases with multiple LN enlargements and hard to reach enlarged LNs for example by vessel interposition. Because of the unreliability of B-mode criteria, further diagnostic improvements such as elastography and contrast-enhanced EUS are investigated to increase the accuracy of the initial diagnosis.

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.

Endobronchial ultrasound elastography: a new method in endobronchial ultrasound-guided transbronchial needle aspiration

BACKGROUND

TBNA through the flexible bronchoscope is a 37-year-old technology that utilizes a TBNA needle to puncture the bronchial wall and obtain specimens of peribronchial and mediastinal lesions through the flexible bronchoscope for the diagnosis of benign and malignant diseases in the mediastinum and lung.

METHODS

Since 2002, the Olympus Company developed the first generation ultrasound equipment for use in the airway, initially utilizing an ultrasound probe introduced through the working channel followed by incoroporation of a fixed linear ultrasound array at the distal tip of the bronchoscope. This new bronchoscope equipped with a convex type ultrasound probe on the tip was subsequently introduced into clinical practice. The convex probe (CP)-EBUS allows real-time endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) of mediastinal and hilar lymph nodes. EBUS-TBNA is a minimally invasive procedure performed under local anesthesia that has been shown to have a high sensitivity and diagnostic yield for lymph node staging of lung cancer.

RESULTS

In 10 years of EBUS development, the Olympus Company developed the second generation EBUS bronchoscope (BF-UC260FW) with the ultrasound image processor (EU-M1), and in 2013 introduced a new ultrasound image processor (EU-M2) into clinical practice. FUJI company has also developed a curvilinear array endobronchial ultrasound bronchoscope (EB-530 US) that makes it easier for the operator to master the operation of the ultrasonic bronchoscope. Also, the new thin convex probe endobronchial ultrasound bronchoscope (TCP-EBUS) is able to visualize one to three bifurcations distal to the current CP-EBUS.

CONCLUSIONS

The emergence of EBUS-TBNA has also been accompanied by innovation in EBUS instruments. EBUS elastography is, then, a new technique for describing the compliance of structures during EBUS, which may be of use in the determination of metastasis to the mediastinal and hilar lymph nodes. This article describes these new EBUS techniques and reviews the relevant literature.