The value of ultrasound elastography in differential diagnosis of superficial lymph nodes

Role of Sonoelastography in Differentiating Benign From Malignant Cervical Lymph Nodes and Correlating With Pathology

Background and aim

Combined use of ultrasonography and elastography improves diagnostic efficacy in differentiating benign from malignant cervical lymph nodes, thereby helping in treatment planning and reducing unnecessary fine needle aspiration cytology/ biopsy. This study aimed to correlate B-mode ultrasonography, color Doppler imaging, and elastography findings with pathological findings and to calculate sensitivity, specificity, and diagnostic accuracy of ultrasonography and elastography.

Material and methods

Patients underwent ultrasonography (B-mode and color Doppler imaging) followed by elastography. Lymph node morphology on B-mode was assessed based on short axis diameter, short-to-long axis ratio, fatty hilum, echogenicity, and margin. Vascularity of lymph nodes on color Doppler imaging was divided into three patterns. On elastography, lymph nodes were defined based on elastography pattern and strain index.

Results

Among all ultrasonography parameters, fatty hilum was found to have the highest diagnostic accuracy (73%), followed by vascularity pattern (70%). Combined use of all ultrasonography parameters yielded better sensitivity (90%), specificity (88%), and diagnostic accuracy (89%) than individual parameters. Five-scale elastography pattern had 83% sensitivity, 97% specificity, and 89% diagnostic accuracy. In the current study, the use of strain index cut-off of two showed sensitivity of 93%, specificity of 96%, and diagnostic accuracy of 94%. Together, ultrasonography and elastography achieved sensitivity of 96%, specificity of 94%, and diagnostic accuracy of 95%.

Conclusion

Elastography can be a useful adjunct to ultrasonography for the accurate diagnosis of cervical lymphadenopathy. Elastography pattern and cut-off strain index of two can effectively differentiate benign from malignant cervical lymph nodes.

Evaluation of acoustic radiation force impulse imaging in differentiating benign and malignant cervical lymphadenopathy

Background:

The aim of this study was to assess the diagnostic role of acoustic radiation force impulse imaging (ARFI) in differentiating benign and malignant cervical nodes.

Methods:

This was a diagnostic accuracy cross-sectional study. All patients who underwent ultrasound-guided fine-needle aspiration cytology (FNAC) of cervical nodes were included. Patients without FNAC/biopsy and patients in whom cervical nodes were cystic or completely necrotic were excluded. FNAC was used as reference investigation to predict the diagnostic accuracy. In all cases, FNAC was carried out after the B-mode, color Doppler and the ARFI imaging. In patients with multiple cervical lymph nodes, the most suspicious node based on grayscale findings was chosen for ARFI. ARFI included Virtual Touch imaging (VTI), area ratio (AR), and shear wave velocity (SWV) for each node, and the results were compared with FNAC/biopsy.

Results:

The final analysis included 166 patients. Dark VTI elastograms had sensitivity and specificity of 86.2% and 72.1%, respectively, in identifying malignant nodes. Sensitivity and specificity of AR were 71.3% and 82.3%, respectively, for a cutoff of 1.155. Median SWV of benign and malignant nodes was 1.9 [95% confidence interval (CI), 1.56–2.55] m/s and 6.7 (95% CI, 2.87–9.10) m/s, respectively. SWV >2.68 m/s helped in identifying malignant nodes with 81% specificity, 81.6% sensitivity, and 81.3% accuracy. ARFI was found to be inaccurate in tuberculous and lymphomatous nodes.

Conclusion:

Malignant nodes had significantly darker elastograms, higher AR and SWV compared to benign nodes, and SWV was the most accurate parameter. ARFI accurately identifies malignant nodes, hence could potentially avoid unwarranted biopsy.

Sonography and sonoelastography in the detection of malignancy in superficial lymph nodes of dogs

BACKGROUND

The clinical applicability of sonography and sonoelastography (SOE) in the detection of lymph node malignancy in dogs has not been established.

OBJECTIVES

To compare sonographic and sonoelastographic findings between malignant and benign superficial lymph nodes and to evaluate the diagnostic performance of those methods.

ANIMALS

One-hundred sixteen lymph nodes of 54 dogs.

METHODS

A prospective observational study was used to investigate sonographic features and elasticity scores of malignant and benign superficial lymph nodes. Lymph nodes were categorized as malignant or benign according to cytology or histopathology. Quantitative variables were compared using Student's unpaired t test. Prevalence of categorical variables was compared using nonparametric Mann-Whitney U test. Diagnostic performance was calculated by receiver-operating characteristic analysis.

RESULTS

Forty-nine malignant and 67 benign lymph nodes were included. Malignant nodes had larger long axis (LA; P = .0002), short axis (SA; P < .0001) and short-to-long axis ratio (P < .0001) in comparison with benign nodes. Malignant nodes had a higher prevalence of mixed vascular distribution on Doppler color flow mapping (P < .005) and on power Doppler (P < .0001) and higher resistivity index (RI; P < .0001), pulsatility index (P < .0001), and elasticity score (P < .0001) in comparison with benign nodes. Short axis, elasticity score, and RI offered the best accuracies, 80.2%, 78.1%, and 77.7% (P < .05), respectively, for malignancy detection.

CONCLUSIONS AND CLINICAL IMPORTANCE

Results support the use of Doppler sonography and SOE as auxiliary methods to brightness mode sonography to detect nodal malignancy.

Head and neck ultrasound: technical advances, novel applications and the role of elastography

High-resolution ultrasound (US) provides superb anatomical detail in the superficial anatomy of the neck and has become the first-line imaging investigation for neck lumps and a crucial component of clinical pathways. In this article, a wide range of advances in neck US are described with a focus on the emerging role of ultrasound elastography. Selected examples of clinical utility are presented across a spectrum of scenarios with discussion of newer applications, service delivery, and training issues. The changing role of the neck ultrasound practitioner and the future of the technique in the head and neck are considered.

Comparative study of three sonoelastographic scores for differentiation between benign and malignant cervical lymph nodes

PURPOSE

The aim of the study was to explore the diagnostic value of three different sonoelastographic scoring systems (labeled S1-S3) for the differentiation between benign and malignant cervical lymph nodes.

MATERIALS AND METHOD

The authors propose a six pattern scoring system of the elastographic images with pattern 1 - representing purely soft nodes, pattern 2 - predominantly soft nodes, pattern 3 - predominantly soft nodes with focal had area, pattern 4 - predominantly hard node, pattern 5 - entirely hard node and pattern 6 - node with necrosis. The sonoelastographic images of 50 benign and 70 malignant lymph nodes were assessed. The area under the ROC curve (AUROC) for the differentiation between benign vs. malignant and benign vs. metastatic nodes were analyzed for the three scoring systems.

RESULTS

When all the malignant lymph nodes were considered, the S1 score showed an AUROC=0.873 (95%CI [0.805-0.918], where CI=confidence interval; p<0.001), sensibility (Se)=58.57%, and specificity (Sp)=96%. For S2 score the AUROC was 0.890 (95%CI [0.824-0.933], p<0.001), Se=92.86%, and Sp=72%. For S3 score, the AUROC was 0.852 (95%CI [0.778-0.902], p<0.001), Se=64.29%, and Sp=94%). When lymphomatous nodes were excluded, for S1 the AUROC was 0.884 (95%CI [0.809-0.932], p<0.001), Se=64%, and Sp=96%. For S2 the AUROC was 0.894 (95%CI [0.818-0.939], p<0.001), Se=92%, and Sp=72%. For S3, the AUROC was 0.856 (95%CI [0.771-0.911], p<0.001), Se=66%, and Sp=94%. In the S3 scoring system, setting the benign vs. malignant cut off at pattern 3 increases the sensibility (41-65%) with minimal loss of specificity (96-94%). From the gray-scale and Doppler criteria, changes of the nodular margins and the presence of the vessels in the cortical part of the lymph node showed both very high sensibility and specificity, the others criteria taken into account had either very good sensibility with low specificity or high specificity and low sensibility.

CONCLUSIONS

Our study suggests that there are no significant differences between the three scoring systems in terms of overall diagnostic value.

Ultrasound elastography for evaluation of cervical lymph nodes

Ultrasound (US) elastography has been introduced as a noninvasive imaging technique for evaluating cervical lymph nodes. US elastography techniques include strain elastography and shear wave-based elastography. The application of this technique is based on the fact that stiff tissues tend to deform less and show less strain than compliant tissues when the same force is applied. In general, metastatic lymph nodes demonstrate higher stiffness than benign lymph nodes. Overall, preliminary studies suggest that US elastography may be useful in differentiating benign and malignant cervical lymph nodes, thereby informing decisions to perform a biopsy and facilitating follow-up. For US elastography to be accepted into clinical practice, however, its techniques, associated diagnostic criteria, and reliability need to be further refined.

B-mode and elastosonographic evaluation to determine the reference elastosonography values for cervical lymph nodes

Background. It is crucial to differentiate between reactive and malignant lymphadenopathies. Elastosonography measures the elasticity of the tissue. Having a reference value for benign lymph nodes (LNs) is important in interpretation. The purpose of this study is to determine the reference elastosonography values of cervical LNs. Methods. 97 LNs were evaluated by B-mode and elastosonography. Depth, length, width, length to width ratio, hilar-cortical thickness, strain ratio, and elasticity scores were measured. Results. In 18.6% of the cervical LNs cortical thickness was less than the hilar thickness (group A) and in 81.4% it was equal or more (group B). 69.1% of LNs showed strain ratio (SR) less than 3 (group 1) and 30.9% equal to or more than 3 (group 2). 33% of LNs displayed elasticity score (ES) 1; 30.9% ES 2; 22.7% ES 3, and 13.4% ES 4. There was a significant correlation between thickness ratios and elasticity scores (P: 0.011). A significant correlation was also demonstrated between SR groups and elasticity scores. Conclusion. A simple, reproducible, noninvasive imaging technique for diagnosis of malignant LNs is necessary. Elastosonography can aid in the differentiation of benign versus malignant cervical LNs, thus help reduce the number of unnecessary biopsies for benign processes.

Endoscopic ultrasound-guided elastography in the nodal staging of oesophageal cancer

AIM: To assess quantitative endoscopic ultrasound (EUS)-guided elastography in the nodal staging of oesophago-gastric cancers.

METHODS: This was a single tertiary centre study assessing 50 patients with established oesophago-gastric cancer undergoing EUS-guided fine needle aspiration biopsy (FNAB) of lymph nodes between July 2007 and July 2009. EUS-guided elastography of lymph nodes was performed before EUS-FNAB. Standard EUS characteristics were also described. Cytological determination of whether a lymph node was malignant or benign was used as the gold standard for this study. Comparisons of elastography and standard EUS characteristics were made between the cytologically benign and malignant nodes. The main outcome measure was the accuracy of elastography in differentiating between benign and malignant lymph nodes in oesophageal cancers.

RESULTS: EUS elastography and FNAB were performed on 53 lymph nodes. Cytological malignancy was found in 23 nodes, one was indeterminate, one was found to be a gastrointestinal stromal tumor and 25 of the nodes were negative for malignancy. On 3 occasions insufficient material was obtained for analysis. The area under the curve for the receiver operating characteristic curve for elastography strain ratio was 0.87 (P < 0.0001). Elastography strain ratio had a sensitivity 83%, specificity 96%, positive predictive value 95%, and negative predictive value 86% for distinguishing between malignant and benign nodes. The overall accuracy of elastography strain ratio was 90%. Elastography was more sensitive and specific in determining malignant nodal disease than standard EUS criteria.

CONCLUSION: EUS elastography is a promising modality that may complement standard EUS and help guide EUS-FNAB during staging of upper gastrointestinal tract cancer.

Real-time elastography for the differentiation of benign and malignant superficial lymph nodes: a meta-analysis

BACKGROUND

Real-time elastography (RTE), as a non-invasive method, is used for the classification of benign and malignant lymph nodes (LNs) and developed as an alternative to biopsy. Elasticity score (ES) and strain ratio (SR) are used for the interpretation of RTE. We studied the performance of RTE for diagnosis of malignant LNs using meta-analysis.

METHODS

PubMed, the Cochrane Library, ISI Web of Knowledge, China National Knowledge Infrastructure were searched. The studies published in English or Chinese relating to the diagnostic value of RTE for superficial LNs were collected. Hierarchical summary receiver operating characteristic (HSROC) curve was used to examine the RTE accuracy. Clinical utility of RTE for LNs was evaluated by Fagan plot analysis.

RESULTS

A total of 9 studies which included 835 LNs were analyzed. The summary sensitivity and specificity for the diagnosis of malignant LNs were 0.74 (95% confidence interval (CI), 0.66-0.81) and 0.90 (95% CI, 0.82-0.94) for ES, and 0.88 (95% CI, 0.79-0.93) and 0.81 (95% CI, 0.49-0.95) for SR, respectively. Compared to ES, SR obviously improved the diagnostic sensitivity value. The HSROCs were 0.88 for ES and 0.91 for SR, respectively. After RTE results over the cut-off value for malignant LNs ("positive" result), the corresponding post-test probability for the presence (if pre-test probability was 50%) was 88% for ES and 82% for SR, respectively; while, in "negative" measurement, the post-test probability was 22% and 13%, respectively.

CONCLUSION

RTE has a high accuracy in the classification of superficial LNs and can potentially help to select suspicious LNs for biopsy.