Reliability of sonoelastography in predicting pediatric cervical lymph node malignancy

Cervical lymph node characterization using point shear wave elastography in pediatric patients: initial experience

BACKGROUND

Sonoelastography, also known as elastography, is a novel noninvasive imaging technique conducted using ultrasound equipment and used to indirectly evaluate tissue stiffness by measuring the speed of transverse wave propagation, or shear wave velocity, through the target tissue. Elastography is useful in diagnosing malignant lesions, which are stiffer than healthy tissue due to their high cell density.

OBJECTIVE

The aim of this study was to assess the ability of elastography to differentiate between benign and malignant cervical lymph nodes.

MATERIALS AND METHODS

Over a period of 2.5 years, we prospectively assessed the cervical lymph nodes of pediatric patients who visited the ultrasound department of our institution. In the course of a single procedure, participants underwent B-mode and color Doppler ultrasonography and point shear wave elastography (pSWE) of the cervical lymph nodes. The participants were divided into three groups: control (I), reactive lymph nodes (II), and malignant lymph nodes (III). A histological examination was performed in all patients with suspected malignancy, and mean shear wave velocity was compared across the three study groups.

RESULTS

Significant differences in elastography measurements were found between the lymph nodes in group I (control group) and group III (malignant lymph nodes) (P<0.0001) and between group II (reactive nodes) and group III (malignant nodes) (P<0.0001). Lymph nodes from patients in group III had higher elastography values than those in groups I and II.

CONCLUSION

pSWE is useful in measuring cervical lymph node stiffness, showing promising results in distinguishing between benign/reactive and malignant nodes.

Diagnostic Performance of Ultrasound for Differentiating Malignant From Benign Cervical Lymphadenopathy in Children: A Systematic Review and Meta-Analysis

OBJECTIVES

To evaluate the diagnostic performance of ultrasound (US) features used to differentiate malignant from benign cervical lymphadenopathy in children.

METHODS

PubMed and EMBASE were searched for articles reporting the diagnostic performance of US features to differentiate benign and malignant cervical lymphadenopathy in children. Article quality was evaluated using the QUADAS-2 tool. Sensitivity and specificity were pooled using a bivariate random-effects model. Further sensitivity analyses and meta-regression were performed to determine the potential source of heterogeneity. The area under the receiver operating characteristic curve was calculated using the hierarchical summary receiver operating characteristic model.

RESULTS

Ten articles (1077 children) were included. Among the retrieved US features, abnormal vascularity, heterogeneous echogenicity, abnormal hilum echogenicity, and long-axis/short-axis (L/S) ratio were significantly associated with malignant lymphadenopathy, with pooled diagnostic odds ratios of 36 (95% confidence interval [CI]: 14-92), 17 (3-91), 16 (5-54), and 7 (5-9), respectively. The most sensitive US features were abnormal hilum echogenicity (0.86, 95% CI: 0.66-0.95) and heterogeneous echogenicity (0.84, 95% CI: 0.25-0.99). Abnormal vascularity (0.91, 95% CI: 0.82-0.97) was the most specific. Substantial heterogeneity was found in both sensitivity and specificity (I2 > 50%; P < .01), although the source was not revealed.

CONCLUSION

Among US features, abnormal vascularity, heterogeneous echogenicity, abnormal hilum echogenicity, and L/S ratio are useful for differentiating malignant from benign cervical lymphadenopathy in children, showing good diagnostic performance. These findings should be carefully interpreted due to unexplained heterogeneity, which may lower the validity of the pooled estimates.

Shear wave elastography versus strain elastography to identify benign superficial lymph nodes: sonographic assessment with histopathological confirmation

Background

Differentiation between benign and malignant superficial lymph nodes (LNs) presents clinical dilemma. No specific criteria are established with conventional ultrasound to make a distinction. We aimed to study the added value of shear wave velocity (SWV) measurement with acoustic radiation force impulse (ARFI) and strain elastography (SE) to identify benign superficial LNs. The study included 115 superficial LNs subjected to conventional ultrasonography, 4-scale strain elastography and shear wave velocity measurement using ARFI. Histopathological analysis was obtained for all examined nodes.

Results

SE correctly diagnosed 89.3% of the reactive and 92.2% of the metastatic LNs and erroneously diagnosed 72.7% of the lymphoma LNs as being benign. Overall sensitivity, specificity, PPV, NPV and accuracy were 74.4%, 73%, 85.3%, 57.4% and 73.9%, respectively. The receiver operating curve analysis of SWV measurement using ARFI revealed a cut-off value of ≥ 2.70 m/sec to recognize malignant LNs and to obtain best sensitivity (88.5%) and specificity (89.2%) (Area under the curve: 0.819, 95% confidence interval (CI): 0.744 and 0.894). The PPV, NPV and accuracy were 94.5%, 78.6% and 88.7%, respectively. As compared to SE, ARFI boosted the diagnostic accuracy of lymphoma LNs from 27.3 to 68.2% and showed better specificity and NPV to identify benign LN as contrasted to SE.

Conclusions

SE could be adequate to differentiate reactive from metastatic LN but not from Lymphomas. Shear wave elastography is a reasonable imaging modality to identify benign lymph nodes. ARFI at a cut-off value of < 2.7 m/sec was superior to SE and the best B-mode features.

Ultrasound Elastography in the Diagnosis of Malignant Cervical Lymphadenopathy in Children: Can It Replace Surgical Biopsy?

INTRODUCTION

 We aimed to assess the accuracy of ultrasound elastography in detecting pediatric malignant cervical lymph nodes, and if this modality can obviate the need for surgical biopsies.

MATERIAL AND METHODS

 A prospective study from September 2017 to September 2020 included 64 children with persistent cervical lymphadenopathy. Patients were evaluated by meticulous history and physical assessment. B-mode ultrasound, color Doppler, and sonoelastography were conducted thereafter. Elastography scans were classified into five patterns, and patterns from 3 to 5 were considered as malignancies. All children underwent open biopsies followed by pathological examination. Results of tissue diagnosis were compared with patterns of elastography to determine its accuracy.

RESULTS

 Twenty-eight patients (43.8%) had malignant nodes and the remaining 36 (56.2%) were due to benign causes. Elastography patterns of 1 and 2 were documented in 30 patients, and all of them were diagnosed as benign lesions. Patterns of 3 to 5 were demonstrated in 34 patients. Out of them, 28 were confirmed as malignancies, while 6 children were of benign nature (false positive). Ultrasound elastography achieved sensitivity and specificity of 100 and 85.7%, respectively, and an overall accuracy of 90.6% in the differentiation between malignant and benign entities. The overall accuracy of B-mode and color Doppler were 75 and 82.2%, respectively.

CONCLUSION

 Elastography is a useful tool that should be added to ultrasound modalities during the diagnosis of pediatric cervical lymphadenopathy. Surgical biopsy in eligible patients is imperative to commence proper therapy or to discharge the child. Despite favorable results of elastography, it cannot replace surgical biopsy or change its indications.

Ultrasound elastography in children - nice to have for scientific studies or arrived in clinical routine?

Ultrasound elastography (USE) is a modality that in addition to fundamental B-mode, Doppler, and contrast-enhanced sonography is suitable to make qualitative and quantitative statements about the stiffness of tissues. Introduced more than 20 years ago in adults, USE becomes now a diagnostic tool also in children. The aim of this paper is to describe current available techniques for USE in children. The significance for routine use in children is shown, and further interesting applications are reported.

Exploratory study on the predictive value of ultrasound radiomics for cervical tuberculous lymphadenitis

PURPOSE

To investigate the predictive values of gray-scale ultrasound (G-US) and strain elastic ultrasound (SE-US) radiomic features for cervical tuberculous lymphadenitis (CTL).

MATERIAL AND METHODS

The G-US and SE-US images of 147 patients with pathologically confirmed CTL and 69 non-CTL patients were retrospectively analyzed. A total of 851 imaging features were extracted. The patients were divided into the training set and test set in 7:3 ratio. In the training set, the minimum redundancy maximum relevance (mRMR) and the least absolute shrinkage and selection operator (LASSO) were used for feature selection and modeling. The diagnostic power of G-US and SE-US ultrasound radiomics in identifying CTL was evaluated in test set.

RESULTS

The G-US and SE-US have finally selected 10 and 14 features, respectively. In the G-US group, the diagnostic sensitivity, specificity and accuracy of the training set were 69.7%, 85.7% and 70.0%, respectively, and those values in the test set were 81.3%, 70.0% and 86.4%, respectively. The SE-US group had a sensitivity of 71.7%, a specificity of 81.6%, and an accuracy of 67.0% in the training set, and those parameters in the test set were 81.0%, 75.0%, and 83.7%, respectively. In the G-US group, the positive and negative predictive value of the training set were 0.519 and 0.901, respectively, and those values in the test set were 0.700 and 0.864, respectively. The SE-US group had a positive predictive value of 0.541, and a negative predictive value of 0.885 in the training set, and those parameters in the test set were 0.682 and 0.878, respectively. By Delong test, G-US and SE-US groups showed no significant differences in diagnostic performance between the training and test sets.

CONCLUSIONS

The ultrasound radiomic features of G-US and SE-US exhibited certain predictive potential in detecting CTL, providing a new non-invasive method for clinicians to more accurately evaluate patients with CTL.

Imaging in children with ataxia-telangiectasia-The radiologist's approach

Ataxia-telangiectasia (A-T) is a syndromic inborn error of immunity (IEI) characterized by genomic instability, defective reparation of the DNA double-strand breaks, and hypersensitivity to ionizing radiation disturbing cellular homeostasis. The role of imaging diagnostics and the conscious choice of safe and advantageous imaging technique, as well as its correct interpretation, are crucial in the diagnostic process and monitoring of children with A-T. This study aimed at defining the role of a radiologist in the early diagnosis of A-T, as well as in detecting and tracking disease complications associated with infections, inflammation, lymphoproliferation, organ-specific immunopathology, and malignancy. Based on our single-center experience, retrospective analysis of investigations using ionizing radiation-free techniques, ultrasound (US), and Magnetic Resonance Imaging (MRI), was performed on regularly followed-up 11 pediatric A-T patients, 6 girls and 5 boys, aged from 2 to 18 years, with the longest period of observation coming to over 13 years. Our attention was especially drawn to the abnormalities that were observed in the US and MRI examinations of the lungs, abdominal cavity, and lymph nodes. The abdominal US showed no abnormalities in organ dimensions or echostructure in 4 out of 11 children studied, yet in the other 7, during follow-up examinations, hepato- and/or splenomegaly, mesenteric, visceral, and paraaortic lymphadenopathy were observable. In 2 patients, focal changes in the liver and spleen were shown, and in one patient progressive abdominal lymphadenopathy corresponded with the diagnosis of non-Hodgkin lymphoma (NHL). The lung US revealed multiple subpleural consolidations and B line artifacts related to the interstitial-alveolar syndrome in 5 patients, accompanied by pleural effusion in one of them. The MRI investigation of the lung enabled the detection of lymphatic nodal masses in the mediastinum, with concomitant airway lesions characteristic of bronchiectasis and focal parenchymal consolidations in one A-T patient with chronic respiratory failure. This patient also manifested organomegaly and granulomatous liver disease in abdominal MRI examination. Our study shows that the use of modern US capabilities and MRI is safe and efficient, thereby serving as a recommended advantageous imaging diagnostic tool in monitoring children with IEI and DNA instability syndromes.

Pancreatic shear wave elastography in children with type 1 diabetes: relation to diabetes duration, glycemic indices, fasting C-peptide and diabetic complications

BACKGROUND

Little is known about changes in the pancreas as the course of type 1 diabetes progresses. Recently, shear wave elastography (SWE) emerged as a tool for assessing pancreatic stiffness in chronic pancreatitis and pancreatic cancer with a few studies assessing it in diabetes.

OBJECTIVE

To compare pancreatic SWE in children with recent-onset and long-standing type 1 diabetes to healthy controls and to correlate it with diabetes duration, glycated hemoglobin (HbA1C), functional B cell reserve (fasting C-peptide) and diabetic complications.

MATERIALS AND METHODS

Fifty children with type 1 diabetes (25 with recent-onset and 25 with long-standing type 1 diabetes) and 50 controls were enrolled. Diabetes duration, insulin therapy, fundoscopic examination of the eyes and the neuropathy disability score were assessed. Fasting C-peptide, lipids, HbA1C and urinary albumin-creatinine ratio were measured. Pancreatic SWE was measured using the General Electric Logiq P9 ultrasound system.

RESULTS

The mean SWE of the studied children with recent-onset type 1 diabetes was 4.81±0.62 kilopascals (Kpa), those with long-standing type 1 diabetes was 7.10±1.56Kpa and for controls was 5.57±0.27 Kpa (P&lt;0.001). SWE was positively correlated to diabetes duration (P&lt;0.001) and negatively correlated to fasting C-peptide (P&lt;0.001). Regarding diabetes complications, SWE was positively correlated to frequency of severe hypoglycemia (P=0.005), HbA1C (P=0.03), low-density lipoproteins (P&lt;0.001) and cholesterol (P&lt;0.001) and significantly related to diabetic neuropathy (P=0.04) and nephropathy (P=0.05). Diabetes duration, fasting C-peptide, HbA1C and frequency of severe hypoglycemia were the significant independent variables related to SWE increase by multivariable regression analysis.

CONCLUSION

Pancreatic SWE changes significantly with duration of type 1 diabetes, being lowest in those with recent-onset type 1 diabetes and highest in those with long-standing type 1 diabetes, particularly those with diabetic nephropathy and neuropathy.

Clinical Value of Shear Wave Elastography Color Scores in Classifying Thyroid Nodules

Objective

To evaluate the clinical value of qualitative shear wave elastography (SWE) color in the differential diagnosis of benign and malignant thyroid nodules.

Methods

From January 2017 to July 2018, 241 patients with 261 thyroid nodules, who underwent conventional ultrasonography and SWE examination before surgical resection, were enrolled. The nodules were also evaluated by histopathologic analyses. The SWE color characteristics that could differentiate malignant and benign thyroid nodules were selected and scored based on the malignancy rate. The diagnostic performances were evaluated by receiver operating characteristic (ROC) curves analysis.

Results

Among the 261 thyroid nodules, 58 were benign, and 203 were malignant. Malignancy was associated with orange or red as the color of maximum hardness inside a nodule, green as the primary color, with a “stiff rim,” inhomogeneous internal color, and inhomogeneous color between the nodules and its surrounding areas. The SWE color scores for benign thyroid nodules were mainly 0 and 1, while 4 and 5 were for malignant thyroid nodules. The area under the ROC curve (AUC) of the SWE color score ≥3 for the diagnosis of malignant thyroid nodules was 0.828 (95% CI: 0.764, 0.891) with a sensitivity of 82.8%, a specificity of 82.8%, and an accuracy of 83.1%. Additionally, conventional ultrasound combined with SWE color scores had a higher diagnostic performance than conventional ultrasound (AUC 0.820 vs AUC 0.796, P = 0.04).

Conclusion

The SWE color scores might be a convenient and effective method to assist in differentiating thyroid nodules.

Accuracy of shear wave elastography in characterization of thyroid nodules in children and adolescents

BACKGROUND

Thyroid nodules are an important health problem in children and adolescents. They possess a higher risk of malignancy in comparison to adults. This fact forms a great dilemma for clinicians. The aim of this study was to evaluate the reliability of shear wave elastography (SWE) as a non-invasive technique in the characterization of thyroid nodules in children and adolescents.

METHODS

This prospective study included 56 patients with thyroid nodules. All the patients underwent clinical assessment, laboratory investigations, ultrasound, and Doppler examination, followed by an SWE assessment. Statistical analysis was performed and the best cut-off value to differentiate benign from malignant nodules was determined using the ROC curve and AUC.

RESULTS

Seventy-two nodules were detected in the examined patients (ages ranged from 11 to 19 years, with mean age of 14.89 ± 2.3 years). Fifty-eight nodules (80.6%) were benign, and fourteen nodules (19.4%) were malignant (histopathologically proved). Highly suspicious criteria for prediction of malignancy by ultrasound and Doppler were hypoechoic echopattern, internal or internal and peripheral vascularity, microcalcifications, taller-than-wide dimensions, irregular outlines, and absence of halo (p < 0.05). The diagnostic performance for their summation was 70.69% sensitivity, 82.8% specificity, 80.45% accuracy, a 63.79% positive predictive value (PPV), and 87.9% negative predictive values (NPV). Regarding SWE, our results showed that 42.2 kPa was the best cut-off value, with AUC = 0.921 to differentiate malignant from benign nodules; the diagnostic performance was 85.71% sensitivity, 94.83% specificity, 93.06% accuracy, 76.9% PPV, and 93.2% NPV.

CONCLUSION

Shear wave elastography is a non-invasive technique that can assist in the diagnosis of malignant thyroid nodules among children and adolescents.

Estimation of Accuracy of B-Mode Sonography and Elastography in Differentiation of Benign and Malignant Lymph Nodes With Cytology as Reference Standard: A Prospective Study

Purpose: To prospectively estimate the reliability of B-mode ultrasonography and sonoelastography in differentiating benign and malignant cervical lymph nodes with cytological findings as to the reference standard.

Materials and Methods: A total of 50 patients referred for sonography for enlarged cervical lymph nodes were included in the study. They were subjected initially to B-mode ultrasonography and sonoelastography and later underwent fine-needle aspiration cytology (FNAC) in the same sitting. Sensitivity, specificity, and accuracy were compared.

Results: Out of 50 cases, 33 were males, and 17 were females. On B-mode ultrasonography, 15 enlarged cervical lymph nodes were benign-looking and 35 were malignant-looking. When studied on elastography, 12 were benign-looking and 38 showed features of malignancy. However, when studied histopathologically, 18 were benign and 32 were malignant. The sensitivity, specificity, and diagnostic accuracy were compared, and the results were better in sonoelastography than B-mode ultrasonography. When both B-mode and sonoelastography were combined, an increase in the sensitivity for differentiation was achieved. However, a decrease in specificity was noted when both modalities were combined in our study, probably due to a significant number of patients with tuberculous cervical lymphadenopathy.

Conclusion: In countries like India, where granulomatous infection like tuberculosis is prevalent, the combination of sonoelastography with B-mode ultrasonography has decreased specificity in the differentiation of benign and malignant cervical lymph nodes, and histopathology is always needed for the final confirmation of diagnosis. The decreased specificity on elastography is attributed to simultaneous coexisting inflammation and fibrosis in chronic granulomatous lymphadenopathy.

Dual-mode ultrasound radiomics and intrinsic imaging phenotypes for diagnosis of lymph node lesions

Background

The ultrasonic diagnosis of lymph node lesions is usually based on a small number of subjective visual features from a single ultrasonic modality, which limits diagnostic accuracy. Therefore, our study aimed to propose a computerized method for using dual-mode ultrasound radiomics and the intrinsic imaging phenotypes for accurately differentiating benign, lymphomatous, and metastatic lymph nodes.

Methods

A total of 543 lymph nodes from 538 patients were examined with both B-mode ultrasonography and elastography. The data set was randomly divided into a training set of 407 nodes and a validation set of 136 nodes. First, we extracted 430 radiomic features from dual-mode images. Then, we combined the least absolute shrinkage and selection operator with the analysis of variance to select several typical features. We retrieved the intrinsic imaging phenotypes by using a hierarchical clustering of all radiomics features, and we integrated the phenotypes with the selected features for the classification of benign, lymphomatous, and metastatic nodes.

Results

The areas under the receiver operating characteristic curves (AUCs) on the validation set were 0.960 for benign vs. lymphomatous, 0.716 for benign vs. metastatic, 0.933 for lymphomatous vs. metastatic, and 0.856 for benign vs. malignant.

Conclusions

The radiomics features and intrinsic imaging phenotypes derived from the dual-mode ultrasound can capture the distinctions between benign, lymphomatous, and metastatic nodes and are valuable in node differentiation.