New ultrasound techniques for lymph node evaluation

Identifying Functional Lymph Nodes in Lower Extremity Lymphedema Patients: The Role of High-frequency Ultrasound

BACKGROUND

 Lymph nodes may play a potential role in lymphedema surgery. Radiologic evaluation of nodes may reveal the status of pathologic conditions but with limited accuracy. This study is the first to evaluate the efficacy of ultrasound in detecting functioning nodes in lymphedema patients and presents a criterion for determining the functionality of the lymph nodes.

METHODS

 This retrospective study reviews 30 lower extremity lymphedema cases which were candidates for lymph node to vein anastomosis. Lymphoscintigraphy and magnetic resonant lymphangiography (MRL) imaging were compared with ultrasound features which were correlated to intraoperative indocyanine green (ICG) nodal uptake as an indication of functionality.

RESULTS

 Majority were International Society of Lymphology stage 2 late (50.0%) and stage 3 (26.7%). ICG positive uptake (functioning nodes) was noted in 22 (73.3%), while 8 patients (26.6%) had negative uptake (nonfunctioning). Ultrasound had significantly the highest specificity (100%) for identifying functional nodes followed by lymphoscintigraphy (55%) and MRL (36%; p = 0.002, p < 0.001, respectively). This was associated with 100% positive predictive value compared against lymphoscintigraphy (44%) and MRL (36%; p < 0.001 for both). The identified ultrasound imaging criteria for functioning lymph node were oval lymph node shape (Solbiati Index), morphology, vascularity pattern, and vascularity quantification.

CONCLUSION

 The use of ultrasound in nodal evaluation was proven effective in different pathologic conditions and demonstrated the best prediction for functionality of the lymph node based on the new evaluation criteria.

M-mode ultrasound for assessment of the "tethered fat sign" in children: an easily performed way to certify a dynamic process as a still picture

Background

Omental infarction is a rare pediatric disease. Ultrasound is a useful modality for a non-invasive pre-operative differential diagnosis between inflammatory conditions (as appendicitis) and omental infarction, especially by detecting immobility of the omentum adhered to the abdominal wall ("tetherd fat sign"). However, this is a dynamic sign that cannot be documented in a static image with B-mode technique. The goal of this work is to incorporate the versatile function of motion mode (M-mode) into omental infarction diagnosis to describe how the M-mode is useful in the evaluation of fat motion in children suspected of having omental infarction. In 2019 we suggested a new Ultrasound sign named "tethered fat sign" for an accurate non-invasive diagnosis of omental infarction in children. This finding was observed in 6 of the 234 seen children of our previous study with 4 laparoscopic confirmed diagnosis.

Methods

From January 2019 to July 2021, we evaluated 195 children (91 boys and 104 girls, from 3 to 15 years) admitted to our Santobono-Pausilipon Children Hospital with acute right-sided abdominal pain. Abdominal ultrasound was performed to all the patients and the investigation of "tethered fat sign" was always included.

Results

In 7 patients ultrasound showed the presence of a hyperechoic oval mass localized in the right upper abdominal quadrant and in 2 of these M-mode documented a normal subhepatic fat moving during respiratory movements in relation with the abdominal wall. The remaining 5 patients had an omental infarction showed as a subhepatic motionless mass tethered to the abdominal wall on M-mode. In these patients, a sonographic follow-up was performed every 15 d for 2 months showing a progressive reduction in size of the right-sided hyperechoic mass.

Conclusions

In the evaluation of all children who showed the presence of the "tethered fat sign" the use of M-mode provide a certified image in diagnostic ultrasound.

The Use of Contrast-Enhanced Sonography for Therapy Monitoring of Metastatic Lymph Nodes: A Systematic Review

Metastatic cervical lymph nodes are a frequent finding in head and neck squamous cell carcinoma (HNSCC). If a non-surgical approach is primarily chosen, a therapy response evaluation of the primary tumor and the affected lymph nodes is necessary in the follow-up. Supplementary contrast-enhanced ultrasound (CEUS) can be used to precisely visualize the microcirculation of the target lesion in the neck, whereby malignant and benign findings differ in their uptake behavior. The same applies to many other solid tumors. For various tumor entities, it has already been shown that therapy monitoring is possible through regular contrast-enhanced sonography of the primary tumor or the affected lymph nodes. Thus, in some cases, maybe in the future, a change in therapy strategy can be achieved at an early stage in the case of non-response or, in the case of therapy success, a de-escalation of subsequent (surgical) measures can be achieved. In this paper, a systematic review of the available studies and a discussion of the potential of therapy monitoring by means of CEUS in HNSCC are presented.

[Use of Contrast enhanced Ultrasound (CEUS) in the Head and Neck Area: Update]

With the help of contrast enhanced ultrasound, the diagnostic accuracy of conventional sonography can be increased in many areas of otorhinolaryngology. Vascularisation and tissue perfusion can be objectified through the examination. This offers promising approaches for example to monitor the therapy of metastatic cervical lymph nodes or in the treatment of vascular malformations. Contrast Enhanced Ultrasound (CEUS) also offers great potential for differential diagnosis, for example of thyroid nodules. Valid threshold values for the quantitative time intensity curve (TIC) analysis of cervical pathologies are currently still not available. Further studies are necessary. As there is currently no license for the use of contrast enhanced ultrasound in otorhinolaryngology patients must be informed about its off-label use before the examination. This article is intended to provide an overview of the current possibilities and to serve as an introduction to the topic.

Multi-modality parathyroid imaging: A shifting paradigm

The goal of parathyroid imaging in hyperparathyroidism is not diagnosis, rather it is the localization of the cause of hyperparathyroidism for planning the best therapeutic approach. Hence, the role of imaging to accurately and precisely localize the abnormal parathyroid tissue is more important than ever to facilitate minimally invasive parathyroidectomy over bilateral neck exploration. The common causes include solitary parathyroid adenoma, multiple parathyroid adenomas, parathyroid hyperplasia and parathyroid carcinoma. It is highly imperative for the radiologist to be cautious of the mimics of parathyroid lesions like thyroid nodules and lymph nodes and be able to differentiate them on imaging. The various imaging modalities available include high resolution ultrasound of the neck, nuclear imaging studies, four-dimensional computed tomography (4D CT) and magnetic resonance imaging. Contrast enhanced ultrasound is a novel technique which has been recently added to the armamentarium to differentiate between parathyroid adenomas and its mimics. Through this review article we wish to review the imaging features of parathyroid lesions on various imaging modalities and present an algorithm to guide their radiological differentiation from mimics.

Classification of Metastatic Lymph Nodes In Vivo Using Quantitative Ultrasound at Clinical Frequencies

Quantitative ultrasound (QUS) methods characterizing the backscattered echo signal have been of use in assessing tissue microstructure. High-frequency (30 MHz) QUS methods have been successful in detecting metastases in surgically excised lymph nodes (LNs), but limited evidence exists regarding the efficacy of QUS for evaluating LNs in vivo at clinical frequencies (2-10 MHz). In this study, a clinical scanner and 10-MHz linear probe were used to collect radiofrequency (RF) echo data of LNs in vivo from 19 cancer patients. QUS methods were applied to estimate parameters derived from the backscatter coefficient (BSC) and statistics of the envelope-detected RF signal. QUS parameters were used to train classifiers based on linear discriminant analysis (LDA) and support vector machines (SVMs). Two BSC-based parameters, scatterer diameter and acoustic concentration, were the most effective for accurately detecting metastatic LNs, with both LDA and SVMs achieving areas under the receiver operating characteristic (AUROC) curve ≥0.94. A strategy of classifying LNs based on the echo frame with the highest cancer probability improved performance to 88% specificity at 100% sensitivity (AUROC = 0.99). These results provide encouraging evidence that QUS applied at clinical frequencies may be effective at accurately identifying metastatic LNs in vivo, helping in diagnosis while reducing unnecessary biopsies and surgical treatments.

[Radiologic evaluation of lymph nodes in cancer patients]

BACKGROUND

In solid tumors, the detection of locoregional lymph node metastases is of decisive importance not only for the prognosis but also for selecting the correct treatment. Various noninvasive imaging methods or, classically, lymph node dissection are available for this purpose.

OBJECTIVE

This article presents the general principles of noninvasive lymph node diagnostics and discusses the value of the clinically available imaging modalities, ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET). In addition, recent new technical developments of each modality are highlighted.

MATERIAL AND METHODS

Literature search and summary of the clinical and scientific experience of the authors.

RESULTS

The available imaging procedures are divided into (1) morphological (US, CT, MRI) and (2) functional modalities (PET, special MRI). The former capture structural lymph node parameters, such as size and shape, while the latter address properties that go beyond morphology (e.g. glucose metabolism). The high diagnostic accuracy required for future treatment algorithms will require a combination of both aspects.

DISCUSSION/CONCLUSION

Currently, none of the available modalities have sufficient accuracy to replace lymph node dissection in all oncological scenarios. One of the major challenges for interdisciplinary oncological research is to define the optimal interaction between imaging and lymph node dissection for different malignancies and tumor stages.

Imaging evaluation of lymphoma in pregnancy with review of clinical assessment and treatment options

Lymphoma-related malignancies can be categorized as Hodgkin's lymphoma (HL) or non-Hodgkin's lymphoma (NHL) based on histologic characteristics. Although quite rare during pregnancy, HL and NHL are the fourth and fifth most common malignancies during the pregnancy period, respectively. Given the rarity of lymphoma among pregnant patients, radiologists are usually unfamiliar with the modifications required for staging and treatment of this population, even those who work at centers with busy obstetrical services. Therefore, this manuscript serves to not only review the abdominopelvic imaging features of lymphoma in pregnancy, but it also discusses topics including birthing parent and fetal lymphoma-related prognosis, both antenatal and postpartum, current concepts in the management of pregnancy-related lymphoma, as well as the current considerations regarding birthing parent onco-fertility.

Correlation between physical characteristics of biopsy specimen and disease of cervical lymph node after contrast-enhanced ultrasound

Background

To investigate the correlation between physical characteristics and disease of cervical lymph node biopsy specimens after contrast-enhanced ultrasound.

Methods

All patients were biopsied after CEUS, 235 patients were divided into three groups A, B and C according to the physical characteristics of specimens: 92 patients in group A were complete tissue specimens; 113 patients in group B were discontinuous tissue specimens. There were 30 patients in group C, including a small number of tissue and floc, purulent and bloody specimens. Pathological examination, pathogen culture examination and Gene X-Pert MIB examination were completed for all patients in the three groups, and statistical analysis was conducted on the integrity and traits of the specimens.

Results

Group A included 92 intact tissue specimens, 21 with reactive hyperplasia, 17 with lymphoma, 12 with metastatic carcinoma, 13 with lymphadenopathy, 15 with necrotizing lymphadenitis, and rare lymphadenopathy. In group B, 113 patients were treated with intermittent tissue specimens, including infected lymph nodes, lymphoma in 1 case, metastatic carcinoma in 3 cases and sarcoidosis in 1 case. There were 30 patients in group C, including a small amount of tissue and floc, purulent and bloody specimens, all of which were infected lymph nodes. The χ² value of malignant and benign lymph nodes was 42.401, p = 0.000.

Conclusion

The physical characteristics of cervical lymph node biopsy specimens after CEUS are correlated with the disease, which has guiding significance for postoperative specimen selection.

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.

Diagnostic accuracy and clinical impact of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in Positron Emission Tomography - Computed Tomography (PET-CT)-positive mediastinal lymphadenopathies in patients with thoracic or extra-thoracic malignancies

BACKGROUND

The high sensitivity of PET-CT can identify hypermetabolic mediastinal adenopathies during cancer management, but specificity is low and a biopsy is sometimes required to eliminate benign adenopathies.

METHODS

This prospective diagnostic accuracy study included patients with hypermetabolic mediastinal lymphadenopathies revealed on PET-CT during either the initial management of a cancer, treatment evaluation, or monitoring. All patients underwent EUS-FNA. Diagnoses of malignancy based on cytological analysis following EUS-FNA were compared with clinical and radiological follow-up information. The treatment strategy decided before the results of the EUS-FNA pathology reports (Multidisciplinary Team Meeting [MTM-1]) was recorded and compared to the treatment strategy decided once pathological data from EUS-FNA were available (MTM-2).

MAIN FINDINGS

Between 2013 and 2018, 75 patients were included with 47 eligible and evaluable patients. Sensitivity, specificity, and positive and negative predictive values of EUS-FNA were 93%, 100%, 100% and 90%, respectively. The concordance value between the therapeutic strategies determined for MTM-1 and MTM-2 was 44.7%. There were no significant differences in the intensity of fixation on PET-CT between malignant and benign lesions.

CONCLUSION

The diagnostic accuracy of the minimally invasive EUS-FNA procedure is sufficiently robust to avoid the need for diagnostic surgery. The combination of PET-CT and EUS-FNA may alter the therapeutic strategy that would be considered after PET-CT alone.

REGISTRATION

NCT01892501.

To Drain or not to Drain? Point-of-care Ultrasound to Investigate an Axillary Mass: Case Report

INTRODUCTION

Point-of-care ultrasound (POCUS) has great sensitivity in the diagnosis of abscesses and swollen lymph nodes. Many studies outline the characteristics that distinguish abscesses from lymph nodes on POCUS.

CASE REPORT

We present a case from the emergency department in which a patient presented with a potential abscess but was found to have a malignant lymph node on imaging.

CONCLUSION

Point-of-care ultrasound can be used to differentiate an abscess from a swollen lymph node. Abscesses are generally anechoic or hypoechoic with septae, sediment or gas contents, and they lack internal vascularity. Benign lymph nodes are echogenic with hypoechoic cortex with hilar vascularity.

To Drain or not to Drain? Point-of-care Ultrasound to Investigate an Axillary Mass: Case Report

Introduction: Point-of-care ultrasound (POCUS) has great sensitivity in the diagnosis of abscesses and swollen lymph nodes. Many studies outline the characteristics that distinguish abscesses from lymph nodes on POCUS. Case Report: We present a case from the emergency department in which a patient presented with a potential abscess but was found to have a malignant lymph node on imaging. Conclusion: Point-of-care ultrasound can be used to differentiate an abscess from a swollen lymph node. Abscesses are generally anechoic or hypoechoic with septae, sediment or gas contents, and they lack internal vascularity. Benign lymph nodes are echogenic with hypoechoic cortex with hilar vascularity.

[New aspects in fine needle biopsies of the lymph nodes]

BACKGROUND

The cytology of lymph nodes is a cost-effective method with a short turnaround time and low risk to patients that delivers valuable information on the cause of the lymphadenopathies.

OBJECTIVES

To discuss the value of lymph node cytology in the diagnosis of lymph node swellings.

METHODS

Analysis of the causes of the controversially discussed aspects of lymph node cytology. Presentation of the diagnostic groups of lymph node cytology according to the Sydney system.

RESULTS

The technical aspects of lymph node sampling during fine needle biopsy, as well as the subsequent preparation of the correctly fixed direct smears and the triage of the sample for the auxiliary studies, may pose a significant challenge for some puncturers. The whole spectrum of modern pathologic auxiliary studies can be applied to correctly triaged cytologic samples. The diagnoses of fine needle biopsies of the lymph nodes can be divided into five groups according to the recently proposed Sydney reporting system: insufficient/non-diagnostic, benign, atypical, suspicious, and malignant. Further details concerning the diagnosis as well as recommendations on how to proceed are additionally included in cytologic reports.

CONCLUSIONS

The improvement of lymph node sampling as well as the technical aspects of the sample handling, including the application of auxiliary studies, considerably increase the diagnostic value of fine needle biopsy of the lymph nodes. Wide implementation of the usage of the diagnostic groups for reporting fine needle biopsies of the lymph nodes can standardize reporting and improve communication with other clinical specialists.

Diagnostic Model of Superficial Lymph Nodes Based on Clinical History and Ultrasound Findings: A Prospective Cohort Study

OBJECTIVES

Differentiation of benign and malignant changes in lymph nodes is extremely important. We aimed to identify the ultrasound and clinical diagnostic criteria permitting this differentiation.

METHODS

Clinical and ultrasound data were collected at Beijing Friendship Hospital from May 2019 to November 2020. Univariate and multivariate analysis were performed using statistical methods, and a mathematical model was established to evaluate benign and malignant lymph nodes.

RESULTS

A total of 1343 LNs (person) with US-guided core needle or fine needle biopsy (CNB or FNB) were evaluated in the analysis. Variables with a high predictive power were sex (odds ratio, OR: 3.360, p<0.001), short diameter (OR: 4.660, p<0.001), short/long diameter (S/L) ratio (OR: 1.515, P=0.007), border (OR: 1.626, p=0.002), cortex echogenicity (OR: 2.089, P<0.001), fusion (OR: 2.313, p=0.002), vascularity (peripheral vascularity, OR: 3.424, p<0.001; mixed vascularity, OR: 4.127, p<0.001), and medical history (fever/local pain, OR: 0.316, p<0.001; tumor history in the drainage area, OR: 4.595, p<0.001; both, OR: 5.554, p<0.001). The cut-off score on receiver operating characteristic (ROC) curve analysis using these eight variables was 2.5. The largest area under the ROC curve (Az) value was 82.3% (95% confidence interval (CI), 0.805-0.851), and the sensitivity (79.4%), specificity (72.3%), and accuracy (74.8%) were higher than those for nearly all the single indices.

CONCLUSION

The model of combination of ultrasound and clinical symptoms can preliminarily evaluate the benign and malignant of lymph nodes.

Development of Preclinical Ultrasound Imaging Techniques to Identify and Image Sentinel Lymph Nodes in a Cancerous Animal Model

Simple Summary

Bowel cancer is the fourth most common cancer in the UK. Treatment is dominated by major surgery because current imaging modalities cannot accurately determine lymph node involvement or vascular invasion. Although potentially curative, surgery carries a high risk of short- and long-term morbidity, including stoma formation. Optimized pre-treatment imaging would decrease the number of bowel cancer patients requiring major surgery. Such imaging would also be equally applicable to other cancers where local resection could significantly improve patient quality of life without compromising long-term outcomes (e.g., melanoma, head and neck cancers, gastro-esophageal, bladder). In this study, we created two mouse models (tumor and control) and used the resolution of high-frequency ultrasound imaging and parameters calculated from dynamically contrast-enhanced ultrasound to predict the likelihood of draining lymph nodes to be involved in the disease.

Abstract

Lymph nodes (LNs) are believed to be the first organs targeted by colorectal cancer cells detached from a primary solid tumor because of their role in draining interstitial fluids. Better detection and assessment of these organs have the potential to help clinicians in stratification and designing optimal design of oncological treatments for each patient. Whilst highly valuable for the detection of primary tumors, CT and MRI remain limited for the characterization of LNs. B-mode ultrasound (US) and contrast-enhanced ultrasound (CEUS) can improve the detection of LNs and could provide critical complementary information to MRI and CT scans; however, the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) guidelines advise that further evidence is required before US or CEUS can be recommended for clinical use. Moreover, knowledge of the lymphatic system and LNs is relatively limited, especially in preclinical models. In this pilot study, we have created a mouse model of metastatic cancer and utilized 3D high-frequency ultrasound to assess the volume, shape, and absence of hilum, along with CEUS to assess the flow dynamics of tumor-free and tumor-bearing LNs in vivo. The aforementioned parameters were used to create a scoring system to predict the likelihood of a disease-involved LN before establishing post-mortem diagnosis with histopathology. Preliminary results suggest that a sum score of parameters may provide a more accurate diagnosis than the LN size, the single parameter currently used to predict the involvement of an LN in disease.

Contrast-Enhanced Ultrasound Qualitative and Quantitative Characteristics of Parathyroid Gland Lesions

Background and Objectives: preoperative differentiation of enlarged parathyroid glands may be challenging in conventional B-mode ultrasound. The aim of our study was to analyse qualitative and quantitative characteristics of parathyroid gland lesions, using multiparametric ultrasound protocol—B-mode, Colour Doppler (CD), and contrast-enhanced ultrasound (CEUS)—and to evaluate correlation with morphology in patients with hyperparathyroidism (HPT). Materials and Methods: consecutive 75 patients with 88 parathyroid lesions and biochemically confirmed HPT prior to parathyroidectomy were enrolled in the prospective study. B-mode ultrasound, CD, and CEUS were performed with the subsequent qualitative and quantitative evaluation of acquired data. We used 1 mL or 2 mL of intravenous ultrasound contrast agent during the CEUS examination. Correlation with post-surgical morphology was evaluated. Results: seventy parathyroid adenomas were hypoechoic and well contoured with increased central echogenicity (44.3%), peripheral-central vascularization (47%), and polar feeding vessel (100%). Twelve hyperplasias presented with similar ultrasound appearance and were smaller in volume (p = 0.036). Hyperplasias had a tendency for homogenous, marked intense enhancement vs. peripherally enhanced adenomas with central wash-out in CEUS after quantitative analysis. No significant difference was observed in contrasting dynamics, regardless of contrast media volume use (1 mL vs. 2 mL). We achieved 90.9% sensitivity and 72.7% specificity, 93% positive predictive value (PPV), 87.3% negative predictive value (NPV), and 87.3% accuracy in the differentiation of parathyroid lesions prior to post-processing. In a quantitative lesion analysis, our sensitivity increased up to 98%, specificity 80%, PPV 98%, and NPV 80% with an accuracy of 96.4%. Conclusions: CEUS of parathyroid lesions shows potential in the differentiation of adenoma from hyperplasia, regardless of the amount of contrast media injected. The quantitative analysis improved the sensitivity and specificity of differentiation between parathyroid lesions. Hyperplasia was characterized by homogeneous enhancement, fast uptake, and homogeneous wash-out appearance; adenoma—by peripheral uptake, central wash-out, and reduced hemodynamics. The use of CEUS quantification methods are advised to improve the ultrasound diagnostic role in suspected parathyroid lesions.

Comparison of shear-wave velocities obtained with shear-wave elastography of various peripheral lymph nodes in healthy Beagles

OBJECTIVE

To compare shear-wave velocities (SWVs) with shear-wave elastography of various peripheral lymph nodes (LNs).

ANIMALS

11 healthy Beagles.

PROCEDURES

For each dog, bilateral mandibular, medial retropharyngeal, superficial cervical, axillary, superficial inguinal, and popliteal LNs were evaluated with shear-wave elastography in sagittal and transverse scanning planes. Depth of each lymph node was recorded, and intra- and interobserver reliability was determined.

RESULTS

SWVs for all LNs were significantly higher in the sagittal scanning plane, compared with those in the transverse scanning plane. The SWV of the most superficial LN, the mandibular LN, was significantly higher, compared with that for the other LNs, except for the medial retropharyngeal LN. The SWV of the deepest LN, the medial retropharyngeal LN, was as high as that for the mandibular LN. Intra- and interobserver reliability was excellent.

CONCLUSIONS AND CLINICAL RELEVANCE

SWVs for normal peripheral LNs of Beagles may serve as a reference to compare with those for other breeds and diseased LNs. Scanning plane, LN depth, and interfering tissues between the LN and the transducer may affect SWV. Shear-wave elastography may not be operator dependent.

Comparison of shear-wave velocities obtained with shear-wave elastography of various peripheral lymph nodes in healthy Beagles

OBJECTIVE

To compare shear-wave velocities (SWVs) with shear-wave elastography of various peripheral lymph nodes (LNs).

ANIMALS

11 healthy Beagles.

PROCEDURES

For each dog, bilateral mandibular, medial retropharyngeal, superficial cervical, axillary, superficial inguinal, and popliteal LNs were evaluated with shear-wave elastography in sagittal and transverse scanning planes. Depth of each lymph node was recorded, and intra- and interobserver reliability was determined.

RESULTS

SWVs for all LNs were significantly higher in the sagittal scanning plane, compared with those in the transverse scanning plane. The SWV of the most superficial LN, the mandibular LN, was significantly higher, compared with that for the other LNs, except for the medial retropharyngeal LN. The SWV of the deepest LN, the medial retropharyngeal LN, was as high as that for the mandibular LN. Intra- and interobserver reliability was excellent.

CONCLUSIONS AND CLINICAL RELEVANCE

SWVs for normal peripheral LNs of Beagles may serve as a reference to compare with those for other breeds and diseased LNs. Scanning plane, LN depth, and interfering tissues between the LN and the transducer may affect SWV. Shear-wave elastography may not be operator dependent.

Ultrasound and contrast-enhanced ultrasound (CEUS) in infective liver lesions

Infektiöse fokale Leberläsionen (FLL) treten in der klinischen Praxis häufig auf, wobei bakterielle Leberabszesse die Hälfte ausmachen. Eine genaue Diagnose der FLL ist für die Auswahl der am besten geeigneten Therapie und zur Vorbeugung von Komplikationen unerlässlich. Ziel der aktuellen Arbeit ist es, den Nutzen von Ultraschall und kontrastmittelverstärktem Ultraschall (CEUS) zur Erkennung und Charakterisierung infektiöser Leberläsionen zu beschreiben.

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.

Oncologic Imaging of the Lymphatic System: Current Perspective with Multi-Modality Imaging and New Horizon

The lymphatic system is an anatomically complex vascular network that is responsible for interstitial fluid homeostasis, transport of large interstitial particles and cells, immunity, and lipid absorption in the gastrointestinal tract. This network of specially adapted vessels and lymphoid tissue provides a major pathway for metastatic spread. Many malignancies produce vascular endothelial factors that induce tumoral and peritumoral lymphangiogenesis, increasing the likelihood for lymphatic spread. Radiologic evaluation for disease staging is the cornerstone of oncologic patient treatment and management. Multiple imaging modalities are available to access both local and distant metastasis. In this manuscript, we review the anatomy, physiology, and imaging of the lymphatic system.

Application of conventional ultrasonography combined with contrast-enhanced ultrasonography in the axillary lymph nodes and evaluation of the efficacy of neoadjuvant chemotherapy in breast cancer patients

Objective:

Axillary lymph node status assessment has always been an important issue in clinical treatment of breast cancer. However, there has been no effective method to accurately predict the pathological complete response (pCR) of axillary lymph node after neoadjuvant chemotherapy (NAC). The objective of our study was to investigate whether conventional ultrasonography combined with contrast-enhanced ultrasonography (CEUS) can be used to evaluate axillary lymph node status of breast cancer patients after NAC.

Methods:

A total of 74 patients who underwent NAC were recruited for the present study. Prior to and after NAC, examinations of conventional ultrasonography and CEUS were performed. After evaluating the images of conventional ultrasonography, four characteristics were recorded: lymph node medulla boundary, cortex of lymph node, lymph node hilus, and lymph node aspect ratio. Two additional imaging characteristics of CEUS were analyzed: CEUS way and CEUS pattern. Receiver operating characteristiccurve analysis was applied to evaluate their diagnostic performance.

Results:

After 6~8 cycles of NAC, 46 (71.9%) patients had negative axillary lymph node, and 18 (28.1%) patients turned out non-pCR. According to statistical analysis, lymph node medulla, lymph node aspect ratio and CEUS way were independently associated with pCR of axillary lymph node after NAC. The area under the curve of the prediction model with three imaging characteristics was 0.882 (95% confidence interval: 0.608–0.958), and the accuracy to predict the patients’ lymph node status was 78.1% (p < 0.01).

Conclusions:

Conventional ultrasonography combined with CEUS technology can accurately predict axillary lymph nodes status of breast cancer patients after NAC.

Advances in knowledge:

The usefulness of CEUS technology in predicting pCR after neoadjuvant chemotherapy is highlighted.

Sonographic Assessment of the Normal and Abnormal Feline Mammary Glands and Axillary and Inguinal Lymph Nodes

Ultrasound has been used as a diagnostic tool in normal mammary glands and mammary tumors of several species. This study aims to describe the B-mode and Doppler ultrasound features of the mammary glands and draining lymph nodes in 32 adult female cats. Group 1 (G1) consisted of 22 cats without changes in the mammary glands. The average age was 45 ± 25.09 months, where 63.6% (n = 14) were neutered and 31.8% (n = 7) had received progestin at some point for reproductive control. Mammary gland structure was predominantly hypoechoic and homogeneous, with well-defined margins. The average thickness was 1.52 ± 1.59 mm, although it may be affected by estrus, pregnancy, and lactation. In G1, 100% of lymph nodes were homogeneous, 98% were hypoechoic, and 100% were with well-defined margins and hilar vascularization. Group 2 (G2) consisted of 10 cats with mammary nodules. The average age was 88.8 ± 40.5 months, and 70% were intact and all had already received progestin. Ultrasound demonstrated enlarged mammary glands, with nodules of different textures clinically, mainly affecting the abdominal mammary glands (61%). In 33.33%, there were visible mammary ducts. Only 54.17% were homogeneous, 95.83% were hypoechoic, and the margins were regular in 52.08%. Lymph nodes in abnormal mammary chains may present changes in size, shape, echotexture, and echogenicity. Ultrasound examination of the mammary glands and lymph nodes are possible to evaluate the entire mammary chain as well the superficial inguinal and axillary lymph nodes for abnormalities in the feline.

Application of multimodal ultrasonography for differentiating benign and malignant cervical lymphadenopathy

OBJECTIVES

The purpose of this study was to evaluate the diagnostic value of multimodal ultrasonography, including SWE and CEUS, for the differentiation of benign and malignant cervical lymphadenopathy.

METHODS

A total of 103 patients with 109 enlarged neck lymph nodes underwent SWE and CEUS. There were 25 hyperplastic lymph nodes, 66 metastatic lymph nodes, and 18 cases of lymphoma.

RESULTS

Using 31.6 kPa as the Emax cutoff, the sensitivity, specificity and accuracy of measurements on both benign and malignant cervical lymph nodes were 55.95%, 96%, and 65.2%, respectively. CEUS showed that lymph nodes with reactive hyperplasia mainly exhibited uniform perfusion via the lymphatic hilum (18/25; 72%; P < 0.01). The main manifestation of lymphoma was uniform perfusion through the lymphatic hila (10/18; 55.6%; P < 0.01). Metastatic lymph nodes mainly exhibited uneven perfusion (57/66; 86.4%; P < 0.01). The sensitivity, specificity, and accuracy of multimodal ultrasonography for the diagnosis of benign and malignant cervical lymphadenopathies were 90.5%, 72%, and 86.2%, respectively.

CONCLUSIONS

Our findings suggest that multimodal ultrasonography can detect the stiffness (elasticity), perfusion pattern, and characteristics of lymph nodes and is a valuable tool for differentiating between benign and malignant lymphadenopathies.

Imaging of head and neck mucosa-associated lymphoid tissue lymphoma (MALToma)

Marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALToma) arises in extranodal sites in the head and neck. Chronic inflammatory, infectious or autoimmune conditions are implicated in its pathogenesis. Within the head and neck, MALToma is often multifocal and indolent and the imaging appearances may be mistaken for non-malignant disease in the head and neck. The aim of this article is to illustrate the varied radiological and clinical features of MALToma in the head and neck, an awareness of which is needed for timely and correct diagnosis to guide subsequent disease management.

Role of ultrasound in the diagnosis of cervical tuberculous lymphadenitis in children

BACKGROUND

To describe sonographic characteristics of cervical tuberculous lymphadenitis (CTBL) in children, clinical information, and sonograms of 348 lymph nodes (LNs) from 57 children with CTBL were retrospectively analyzed in this study.

METHODS

We retrospectively reviewed the clinical data and sonograms of 348 LNs from 31 boys and 26 girls with CTBL, who were confirmed by pathology or laboratory examination, at the Hangzhou Red Cross Hospital between June 2014 and December 2020. The age of the children ranged from 1 to 14 years (average 7.1 ± 2.9 years).

RESULTS

Night sweats, fatigue and loss of appetite were the most common clinical symptoms observed in children with CTBL. Unilateral LN involvements were common. Occasionally, CTBL was found in healthy children with no symptoms. On sonography, the hilus was absent or unclear in all LNs. The short-to-long axis (S/L) ratio was ≥ 0.5, and the edges were unclear in most LNs. Other accompanying findings included necrosis (47.4%), an echogenic thin layer (36.8%), surrounding soft-tissue edema (38.5%), multiple intra-nodal strong echo (28.2%), sinus (22.7%) and abscess formation (6.9%). The Doppler ultrasound showed that the majority of vascularity patterns of CTBL were capsular or peripheral (33.3%).

CONCLUSIONS

Ultrasound is a recommended examination method for children from different age groups with cervical lymphadenitis. The ultrasonic signs of hilus absence, S/L ratio ≥ 0.5, unclear edge, necrosis, echogenic thin layer, strong echoes and capsular or peripheral vascularity may aid in the diagnosis of cervical tuberculous lymphadenitis.

Utility of quantitative contrast-enhanced ultrasound for the prediction of lymph node metastasis in patients with papillary thyroid carcinoma

OBJECTIVES

The aim of this study was to find the optimal parameters and cutoffs to differentiate metastatic lymph nodes (LNs) from benign LNs in the patients with papillary thyroid carcinoma (PTC) on the quantitative contrast-enhanced ultrasound (CEUS) features.

METHODS

A total of 134 LNs in 105 patients with PTCs were retrospectively enrolled. All LNs were evaluated by conventional ultrasound (US) and CEUS before biopsy or surgery. The diagnostic efficacy of CEUS parameters was analyzed.

RESULTS

Univariate analysis indicated that metastatic LNs more often manifested centripetal or asynchronous perfusion, hyper-enhancement, heterogeneous enhancement, ring-enhancing margins, higher PI, larger AUC, longer TTP and DT/2 than benign LNs at pre-operative CEUS (p <  0.001, for all). Multivariate analysis showed that centripetal or asynchronous perfusion (OR = 3.163; 95% CI, 1.721-5.812), hyper-enhancement(OR = 0.371; 95% CI, 0.150-0.917), DT/2 (OR = 7.408; 95% confidence interval CI, 1.496-36.673), and AUC (OR = 8.340; 95% CI, 2.677-25.984) were predictive for the presence of metastatic LNs. The sensitivity and accuracy of the quantitative CEUS were higher than qualitative CEUS (75% vs 55 % and 83.6% vs 76.1 % , respectively).

CONCLUSIONS

Quantitative CEUS parameters can provide more information to distinguish metastatic from benign LNs in PTC patients; In particular, DT/2 and AUC have a higher sensitivity and accuracy in predicting the presence of metastatic LNs and reduce unnecessary sampling of benign LNs.

Role of Contrast-Enhanced Ultrasound (CEUS) in the Diagnosis of Cervical Lymph Node Metastasis in Nasopharyngeal Carcinoma (NPC) Patients

Objective: The aim of the study was to evaluate the diagnostic value of contrast-enhanced ultrasound (CEUS) in distinguishing between benign and malignant cervical lymph nodes in patients with nasopharyngeal carcinoma (NPC).

Material and Methods: A total of 144 NPC patients with enlarged superficial cervical lymph nodes underwent CEUS examination. The comparison of CEUS image characteristics between malignant and benign cervical lymph nodes was performed in this study as well. We analyzed parameters of the time–intensity curve (TIC), which includes time to peak (TP), area under the gamma curve (AUC), and peak intensity (PI). Furthermore, receiver operating characteristic (ROC) curve analysis was also investigated to evaluate the diagnostic value of CEUS.

Result: We conducted 144 lymph node examinations in total, where 64 cases were biopsy-proven benign nodules and 80 cases were biopsy-proven metastatic nodules. The vast majority of the benign nodes displayed centrifugal perfusion (96.88%, 62/64) and homogeneous enhancement (93.75%, 60/64), while most of the malignant nodes showed centripetal perfusion (92.50%, 74/80) and inhomogeneous 80.00% (64/80). In addition, quantitative analysis showed that CEUS parameters including PI, TP, and AUC in benign lymph nodes (12.51 ± 2.15, 23.79 ± 11.80, and 1110.33 ± 286.17, respectively) were significantly higher than that in the malignant nodes (10.51 ± 2.98, 16.52 ± 6.95, and 784.09 ± 340.24, respectively). The assistance of the three aforementioned parameters and CEUS image characteristics would result in an acceptable diagnostic value.

Conclusion: Our results suggest that imaging perfusion patterns as well as quantitative parameters obtained from CEUS provide valuable information for the evaluation of cervical lymph nodes in NPC patients.

A Proposal for the Performance, Classification, and Reporting of Lymph Node Fine-Needle Aspiration Cytopathology: The Sydney System

BACKGROUND

The evaluation of lymph nodes (LN) by fine-needle aspiration cytology (FNAC) is routinely used in many institutions but it is not uniformly accepted mainly because of the lack of guidelines and a cytopathological diagnostic classification. A committee of cytopathologists has developed a system of performance, classification, and reporting for LN-FNAC.

METHODS

The committee members prepared a document that has circulated among them five times; the final text has been approved by all the participants. It is based on a review of the international literature and on the expertise of the members. The system integrates clinical and imaging data with cytopathological features and ancillary techniques. The project has received the endorsement and patronage of the International Academy of Cytology and the European Federation of the Cytology Societies.

RESULTS

Clinical, imaging, and serological data of lymphadenopathies, indications for LN-FNAC, technical procedures, and ancillary techniques are evaluated with specific recommendations. The reporting system includes two diagnostic levels. The first should provide basic diagnostic information and includes five categories: inadequate/insufficient, benign, atypical lymphoid cells of undetermined/uncertain significance, suspicious, and malignant. For each category, specific recommendations are provided. The second diagnostic level, when achievable, should produce the identification of specific benign or malignant entities and additional information by utilizing ancillary testing.

CONCLUSION

The authors believe that the introduction of this system for performing and reporting LN-FNAC may improve the quality of the procedure, the report, and the communication between cytopathologists and the clinicians. This system may lead to a greater acceptance and utilization of LN-FNAC and to a better interdisciplinary understanding of the results of this procedure.

Announcement: The International System for Reporting Lymph Node Cytopathology

Fine needle aspiration biopsy cytopathology (FNAC) of lymph nodes is a very common, inexpensive, and rapid diagnostic procedure and can lead to the accurate and timely diagnosis of one of the wide range of pathological processes that involve lymph nodes. These diagnoses include specific reactive processes, specific infections such as tuberculosis, metastatic carcinomas and melanomas, and some lymphomas. The FNAC effectively triages the lymph node material, but the initial diagnosis often requires ancillary testing as a second diagnostic step to make a specific diagnosis, such as the particular infectious agent, the type of lymphoma or Hodgkin lymphoma, or the specific type of metastatic malignancy. An international group of cytopathologists have begun the process of developing a system for the standardized reporting of lymph node FNAC. The group is addressing the pre-analytical issues related to the FNAC, including the role of clinical information and the use of ultrasound, and developing a structure of reporting categories based on the cytopathological findings linked to management recommendations. The basis of the system is the integration of the FNAC with the clinical setting, imaging, and ancillary tests that utilize the FNAC material, to produce a final report that will enhance patient care.

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

Objective:

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

Materials and Methods:

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

Results:

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

Conclusion:

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

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

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

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.

Endoscopic Ultrasound Fine-Needle Aspiration versus Fine-Needle Biopsy for Lymph Node Diagnosis: A Large Multicenter Comparative Analysis

Background/Aims

Endoscopic ultrasound fine-needle aspiration (EUS-FNA) is preferred for sampling of lymph nodes (LNs) adjacent to the gastrointestinal wall; however, fine-needle biopsy (FNB) may provide improved diagnostic outcomes. This study aimed to evaluate the comparative efficacy and safety of FNA versus FNB for LN sampling.

Methods

This was a multicenter retrospective study of prospectively collected data to evaluate outcomes of EUS-FNA and EUS-FNB for LN sampling. Characteristics analyzed included sensitivity, specificity, accuracy, the number of needle passes, diagnostic adequacy of rapid on-site evaluation (ROSE), cell-block analysis, and adverse events.

Results

A total of 209 patients underwent EUS-guided LN sampling. The mean lesion size was 16.22±8.03 mm, with similar sensitivity and accuracy between FNA and FNB ([67.21% vs. 75.00%, respectively, p=0.216] and [78.80% vs. 83.17%, respectively, p=0.423]). The specificity of FNB was better than that of FNA (100.00% vs. 93.62%, p=0.01). The number of passes required for diagnosis was not different. Abdominal and peri-hepatic LN location demonstrated FNB to have a higher sensitivity (81.08% vs. 64.71%, p=0.031 and 80.95% vs. 58.33%, p=0.023) and accuracy (88.14% vs. 75.29%, p=0.053 and 88.89% vs. 70.49%, p=0.038), respectively. ROSE was a significant predictor for accuracy (odds ratio, 5.16; 95% confidence interval, 1.15–23.08; p=0.032). No adverse events were reported in either cohort.

Conclusions

Both EUS-FNA and EUS-FNB are safe for the diagnosis of LNs. EUS-FNB is preferred for abdominal LN sampling. EUS-FNA+ ROSE was similar to EUS-FNB alone, showing better diagnosis for EUS-FNB than traditional FNA. While ROSE remained a significant predictor for accuracy, due to its poor availability in most centers, its use may be limited to cases with previous inconclusive diagnoses.

Pediatric Endoscopy, Update 2020

Optimal management of pediatric endoscopy requires a multidisciplinary approach. In most hospitals, endoscopy in pediatric patients is performed by conventional gastroenterologists and only a few centers have specialized pediatric gastroenterologists. This is due to the fact that the number of pediatric gastroenterologists is limited and not all of them are experienced in endoscopic techniques. However, there are also some pediatric centers offering a high-quality and high-volume endoscopy service provided by very experienced pediatric gastroenterologists. Up to now, the literature on pediatric endoscopy is rather sparse. In this article, we describe current knowledge and practice of endoscopic procedures in pediatric patients, which should be relevant for both the adult and pediatric gastroenterologists.

Performance of Molecular Lymphosonography for Detection and Quantification of Metastatic Involvement in Sentinel Lymph Nodes

OBJECTIVES

To assess the performance of molecular lymphosonography with dual-targeted microbubbles in detecting and quantifying the metastatic involvement in sentinel lymph nodes (SLNs) using a swine melanoma model.

METHODS

Targeted microbubbles were labeled with P-selectin and αV β3 -integrin antibodies. Control microbubbles were labeled with immunoglobulin G antibodies. First lymphosonography with Sonazoid (GE Healthcare, Oslo, Norway) was used to identify SLNs. Then dual-targeted and control microbubbles were injected intravenously to detect and quantify metastatic disease in the SLNs. Distant non-SLNs were imaged as benign controls. All evaluated lymph nodes (LNs) were surgically removed, and metastatic involvement was characterized by a histopathologic analysis. Two radiologists blinded to histopathologic results assessed the baseline B-mode images of LNs, and the results were compared to the histologic reference standard. The mean intensities of targeted and control microbubbles within the examined LNs were measured and compared to the LN histologic results.

RESULTS

Thirty-five SLNs and 34 non-SLNs from 13 Sinclair swine were included in this study. Twenty-one SLNs (62%) were malignant, whereas 100% of non-SLNs were benign. The sensitivity of B-mode imaging for metastatic LN diagnosis for both readers was relatively high (90% and 71%), but the specificity was very poor (50% and 58%). The sensitivity and specificity of molecular lymphosonography for metastatic LN detection were 91% and 67%, respectively. The mean intensities from dual-targeted microbubbles correlated well with the degree of metastatic LN involvement (r = 0.6; P < 0.001).

CONCLUSIONS

Molecular lymphosonography can increase the specificity of metastatic LN detection and provide a measure to quantify the degree of metastatic involvement.

Elastography of the Pancreas, Current View

Ultrasound elastography (USE) of the pancreas allows pancreatic tissue stiffness assessment by virtual palpation. Two main types of USE are used. For the pancreas strain elastography applying by endoscopic ultrasound has been established for the characterisation of small solid pancreatic lesions (SPL). In larger SPL >30 mm the results are less convincing mainly due to the heterogenicity of the lesions but also by concomitant changes of the surrounding pancreatic parenchyma. The current role of shear wave elastography has to be determined. This article reviews the current use of elastography of the pancreas.

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.

Evaluation of lymph node metastasis in a rabbit tumor model: correlations between contrast-enhanced ultrasound and pathologic findings

Purpose

The purpose of this study was to evaluate the ability of contrast-enhanced ultrasonography (CEUS) with microbubbles to detect metastatic lymph nodes (LNs) for treatment planning and prognosis.

Methods

For the metastatic LN model, ground VX₂ tumor tissues were injected subcutaneously in 12 rabbits, just below the right hind limb. The rabbits were classified into three groups based on the LN area: group A (n=4, >1.9 cm² ), group B (n=4, 1-1.9 cm² ), and group C (n=4, <1 cm² ). The LNs were monitored on CEUS for 10 seconds after injecting 2.5 mL of microbubbles. The percent area of metastatic LNs was calculated on pathologic images and compared with CEUS images.

Results

In group A, the mean percent area of metastasis was 40.7%±19.4%. In all cases of metastasis, round-shaped perfusion defects were clearly observed in CEUS images. The metastatic areas were strongly correlated with pathologic findings. The mean percent area in group B was 21.5%±14.4%. The CEUS findings showed multiple nodular perfusion defects, clearly revealing the metastatic areas. In group B, the CEUS and pathologic findings were concordant for three of the four cases. The mean percent area in group C was 9.1%±6.4%. However, in this group, CEUS only detected a small perfusion defect in one case.

Conclusion

CEUS has the potential to depict characteristic imaging features of metastatic LNs but still has limitations in early detection.

Diagnostic Value of Arrival Time Parametric Imaging Using Contrast-Enhanced Ultrasonography in Superficial Enlarged Lymph Nodes

OBJECTIVE

The aim of this study was to evaluate the value of arrival-time parametric imaging for differential diagnosis of superficial enlarged lymph nodes.

METHODS

Patients with lymphadenopathy who received contrast-enhanced ultrasonography (CEUS) and biopsy were included in this study. Following CEUS, a prototype software of the arrival-time parametric imaging system was used to analyze the video footage. Arrival-time patterns during the arterial phase were evaluated. The quantitative parameters including arrival time of periphery, arrival time of center, and the travel time (△T) were calculated.

RESULTS

A total of 145 lymph nodes were analyzed. Arrival-time parametric imaging showed that 80.3% of metastatic lymph nodes and 68.4% of lymphoid tuberculosis presented a centripetal perfusion pattern, 76.5% of lymphoma showed complete homogeneous enhancement, and 81.2% of reactive lymph nodes had centrifugal patterns. The arrival time of periphery (sec) of metastatic lymph nodes was substantially earlier than that of lymphoma (11.0 ± 3.1 versus 12.6 ± 3.6; P < .05). The arrival time of center (sec) of metastatic lymph nodes was obviously later than that of lymphoma and reactive lymph nodes (13.4 ± 3.3 versus 10.5 ± 2.9 and 10.6 ± 1.5; P < .05). The travel time (△T) (sec) in metastatic lymph nodes was substantially longer than in reactive lymph nodes and lymphoma (4.2 ± 2.1 versus 2.3 ± 1.6 and 2.9 ± 2.5; P < .05). At a △T cutoff value of 2.75 seconds (using the receiver operating characteristic curve), the sensitivity and specificity in differentiating metastatic lymph nodes from benign lymph nodes (lymphoid tuberculosis and reactive lymph nodes) were 78.9% and 64.7%, respectively.

CONCLUSIONS

Enhanced patterns and parameters of arrival-time parametric imaging during CEUS could provide more information for the differential diagnosis of enlarged superficial lymph nodes.

Ultrasound imaging of abdominal sarcoidosis: State of the art

Since it has been recognized that sarcoidosis (SA) is not an exclusive disorder of the lungs but can also affect other organs such as the liver and spleen, efforts have been made to define specific imaging criteria for the diagnosis of the single organ involvement, and the concept has been reinforced that the exclusion of alternative causes is important to achieve the correct diagnosis. Ultrasound (US) is a useful tool to evaluate patients with suspected abdominal SA, such as of the liver, spleen, kidney, pancreas and other organs, showing findings such as organomegaly, focal lesions and lymphadenopathy. While the diagnosis of abdominal SA is more predictable in the case of involvement of other organs (e.g., lungs), the problem is more complex in the case of isolated abdominal SA. The recent use of contrast-enhanced ultrasound and endoscopic ultrasound elastography has provided additional information about the enhancement patterns and tissue rigidity in abdominal SA. Here we critically review the role of US in abdominal SA, reporting typical findings and limitations of current evidence and by discussing future perspectives of study.

Contrast-enhanced endoscopic ultrasound for the differential diagnosis between benign and malignant lymph nodes: a meta-analysis

Background  The differential diagnosis between benign and malignant lymph nodes (LNs) is crucial for patient management and clinical outcome. The use of contrast-enhanced endoscopic ultrasound (EUS) has been evaluated in several studies with diverse results. The aim of this meta-analysis was to evaluate the pooled diagnostic accuracy of contrast-enhanced EUS (CE-EUS) and contrast-enhanced harmonic EUS (CH-EUS) in this setting. Methods  A systematic electronic search was performed, including all original papers dealing with assessment of the nature of the LNs using CE-EUS or CH-EUS. A meta-analysis was performed to obtain pooled sensitivity, specificity, positive and negative likelihood ratio, and diagnostic odds ratio. The Summary Receiver Operating Characteristic (ROC) Curve method was used to calculate the area under the curve. Statistical analysis was carried out using Meta-Disc V.1.4, Stata V.12.0 and Review Manager V.5.2. Results  Among 210 pertinent studies, four (336 patients) were included in the analysis. The pooled sensitivity was 82.1 % (75.1 - 87.7 %) and pooled specificity was 90.7 % (85.9 - 94.3 %) with significant heterogeneity found in sensitivity; the positive-likelihood ratio (LR) was 7.77 (5.09 - 11.85) and the negative-LR was 0.15 (0.05 - 0.46); the pooled diagnostic odds ratio (DOR) was 54 (15 - 190). Subgroup analysis including studies performed using CH-EUS (two studies, 177 LNs) showed a pooled sensitivity of 87.7 % (77.0 - 93.9 %) and a pooled specificity of 91.8 % (84.5 % - 96.4 %) with no significant heterogeneity; the pooled positive-LR was 9.51 (4.95 - 18.28) and the pooled negative-LR was 0.14 (0.06 - 0.35); pooled DOR was 68.42 (15.5 - 301.4). Conclusions  From these data, CE-EUS is not recommended due to inadequate sensitivity. On the other hand, CH-EUS studies showed optimal accuracy (pooled sensitivity 87.7 % and specificity 91.8 %), comparable to elastography and even EUS-guided fine needle aspiration (EUS-FNA), suggesting a role in the diagnostic algorithm.

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.

Diagnostic Accuracy of Axillary Ultrasonography Compared with Intra-operative Pathological Findings in Patients with Breast Cancer

Objective:

Breast cancer is the most common cancer and leading cause of mortality in women worldwide. Diagnosis of axillary lymph node involvement, frequently by axillary ultrasonography (AUS), is an important step in patients with primary breast cancer, while the gold standard pathological examination is only applicable during surgery. Thus, we aimed to evaluate the predictive value of AUS in detection of lymph node involvement.

Methods:

A total of 56 patients with primary breast cancer, who were candidate of mastectomy were included in this study. A single radiologist performed pre-operative axillary sonography for all the patients and reported the results in a checklist. The results were then compared with intra-operative pathological results of lymph node dissection to evaluate the sensitivity, specificity, positive and negative predictive values of AUS in detection of the disease.

Result:

The results showed that pre-operative AUS had a sensitivity of 63.3%, specificity of 84.6%, positive predictive value of 82.6%, and negative predictive value of 66.6%. Correlation between axillary lymph node characteristics revealed that the absence of fatty hilum, cortical thickness, and loss of ovality of the lymph nodes were the most specific factors in detection of lymph nodes’ involvement.

Conclusion:

AUS has a low sensitivity and cannot determine the presence of micro-metastases and suspicious lymph nodes accurately in early stages of the disease, and it seems that defining new parameters may help for increasing the sensitivity and specificity of the axillary lymph node sonography. Apparently, pathological examination remains the gold standard diagnostic method.

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

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

Hepatic artery resistive index as surrogate marker for fibrosis progression in NAFLD patients: A clinical perspective

Ultrasound (US) can reveal the presence of steatosis in non-alcoholic fatty liver disease (NAFLD), but its diagnostic accuracy to reveal signs of fibrosis is low except in advanced stages of disease (e.g. cirrhosis). Current guidelines suggest the use of clinical algorithms, such as the NAFLD fibrosis score, and elastography to predict the progression of fibrosis, and the integration of elastography improves the detection accuracy of liver stiffness. However, there is a lack of evidence about the correlation between clinical algorithms and conventional US, and elastography is limited by the relative low diffusion, necessity of training, and loss of diagnostic accuracy in patients with high body mass index (BMI), waist circumference, or increased thickness of parietal walls, with consequent significant rates of failure of measurement of liver stiffness. Recently, the measurement of hepatic artery resistive index (HARI) has demonstrated a significant positive correlation with fibrosis degree, as measured with NAFLD fibrosis score, suggesting that the fibrous tissue accumulation may result in increased arterial rigidity and, therefore, in a rise of resistance to flow, and that the different tissue composition of the liver (adipose versus fibrous) can influence HARI differently. These issues should be further investigated because some aspects are still unknown. The limited data currently justify the need of larger, prospective studies aimed at assessing whether HARI correlates with elastography results. In view of their effect on weight loss, serum lipid concentration, and hepatic arterial flow hemodynamics, it could be interesting to evaluate if lifestyle and diet changes can influence significantly HARI values in NAFLD patients.