Contrast-enhanced ultrasound (CEUS) facilitated US in detecting lateral neck lymph node metastasis of thyroid cancer patients: diagnosis value and enhancement patterns of malignant lymph nodes. Eur Radiol. 2014;24:2513-2519. [PMID: 25005826 DOI: 10.1007/s00330-014-3288-5]

Improved diagnosis of small cervical lymph node metastasis using postvascular phase perfluorobutane CEUS in cancer patients

BACKGROUND

Accurate identification of small metastatic lymph nodes (LNs) remains a significant challenge with conventional ultrasound (US) due to its limitations in sensitivity for smaller LNs. The use of contrast-enhanced ultrasound (CEUS), especially with perfluorobutane in the postvascular phase of CEUS, may improve the diagnosis of metastatic LNs in cancer patients. We sought to investigate the diagnostic accuracy of the postvascular phase of CEUS with perfluorobutane in identifying suspected small cervical LNs in cancer patients.

METHODS

This prospective study enrolled consecutive cancer patients with small cervical LNs suspected to be malignant on US from May 2023 to January 2024. All patients underwent CEUS with perfluorobutane injection, followed by observation during the vascular (6-60 s) and postvascular (10-30 min) phases before biopsy. The reference standard was histological assessment of the LNs through biopsy. The US and CEUS features were analyzed to assess the diagnostic performance of the US, vascular phase-CEUS, and postvascular phase-CEUS features, as well as their association with LN size.

RESULTS

The final dataset included 229 participants (mean age, 57 years ± 11 [SD] [range, 28-80]; 121 women) with 229 suspected LNs, including 125 metastatic and 104 benign LNs. Hypo-enhancement or no enhancement in the postvascular phase of CEUS show excellent sensitivity (97%) and a high negative predictive value (93%). The area under the receiver operating characteristic (ROC) curve of postvascular phase-CEUS is 0.763, significantly higher than that for US (0.574; P < 0.001). Compared to US and vascular phase-CEUS, postvascular phase-CEUS demonstrates superior sensitivity (P = 0.022, and < 0.001, respectively) and accuracy (P < 0.001, all) for diagnosing LNs, irrespective of LN size.

CONCLUSIONS

Postvascular phase-CEUS exhibited excellent diagnostic performance in identifying suspected small LNs in cancer patients. Hyper- or isoenhancing small LNs in the postvascular phase of CEUS were unlikely to be malignant, possibly obviating biopsy.

Dual-modal radiomics ultrasound model to diagnose cervical lymph node metastases of differentiated thyroid carcinoma: a two-center study

OBJECTIVES

To establish and validate a dual-modal radiomics nomogram from grayscale ultrasound and color doppler flow imaging (CDFI) of cervical lymph nodes (LNs), aiming to improve the diagnostic accuracy of metastatic LNs in differentiated thyroid carcinoma (DTC).

METHODS

DTC patients with suspected cervical LNs in two medical centers were retrospectively enrolled. Pathological results were set as gold standard. We extracted radiomic characteristics from grayscale ultrasound and CDFI images, then applied lasso (least absolute shrinkage and selection operator) regression analysis to analyze radiomics features and calculate the rad-score. A nomogram based on rad-score, clinical data, and ultrasound signs was developed. The performance of the model was evaluated using AUC and calibration curve. We also assessed the model's diagnostic ability in European Thyroid Association (ETA) indeterminate LNs.

RESULTS

377 DTC patients and 726 LNs were enrolled. 37 radiomics features were determined and calculated as rad-score. The dual-modal radiomics model showed good calibration capabilities. The radiomics model displayed higher diagnostic ability than the traditional ultrasound model in the training set [0.871 (95% CI: 0.839-0.904) vs. 0.848 (95% CI: 0.812-0.884), p<0.01], internal test set [0.804 (95% CI: 0.741-0.867) vs. 0.803 (95% CI: 0.74-0.866), p = 0.696], and external validation cohort [0.939 (95% CI: 0.893-0.984) vs. 0.921 (95% CI: 0.857-0.985), p = 0.026]. The radiomics model could also significantly improve the detection rate of metastatic LNs in the ETA indeterminate LN category.

CONCLUSIONS

The dual-modal radiomics nomogram can improve the diagnostic accuracy of metastatic LNs of DTC, especially for LNs in ETA indeterminate classification.

Application of ultrasound multimodal imaging in the prediction of cervical tuberculous lymphadenitis rupture

Lymph node tuberculosis is particularly common in regions with a high tuberculosis burden, and it has a great risk of rupture. This study aims to investigate the utility of ultrasound multimodal imaging in predicting the rupture of cervical tuberculous lymphadenitis (CTL). 128 patients with unruptured CTL confirmed by pathology or laboratory tests were included. Various ultrasonic image features, including long-to-short-axis ratio (L/S), margin, internal echotexture, coarse calcification, Color Doppler Flow Imaging (CDFI), perinodal echogenicity, elastography score, and non-enhanced area proportion in contrast-enhanced ultrasound (CEUS), were analyzed to determine their predictive value for CTL rupture within a one-year follow-up period. As a result, L/S (P < 0.001), margin (P < 0.001), internal echotexture (P < 0.001), coarse calcification (P < 0.001), perinodal echogenicity (P < 0.001), and the area of non-enhancement in CEUS (P < 0.001) were identified as significant imaging features for predicting CTL rupture. The prognostic prediction showed a sensitivity of 89.29%, specificity of 100%, accuracy of 95.31%, respectively. Imaging findings such as L/S < 2, unclear margin, heterogeneous internal echotexture, perinodal echogenicity changed, and non-enhancement area in CEUS > 1/2, are indicative of CTL rupture, while coarse calcification in the lymph nodes is associated with a favorable prognosis.

The Diagnostic Performance of Multiparametric Ultrasound in the Qualitative Assessment of Inconclusive Cervical Lymph Nodes

BACKGROUND

Enlarged cervical lymph nodes (CLNs) can result from infection or malignancies, and a definitive diagnosis requires histological examination. Ultrasound (US) remains the first-line imaging modality for detection, and new US techniques may improve characterization. The aim of our study was to investigate whether the qualitative assessment of multiparametric US (mpUS) can improve diagnostic performance in the differentiation of benign and malignant CLNs.

METHODS

107 CLNs in 105 patients were examined by preoperative mpUS consisting of B-mode US, color-coded duplex sonography (CCDS), shear wave elastography (SWE) and contrast-enhanced US (CEUS). US images were evaluated in consensus by two experienced US operators. Histopathological examination was used as reference standard.

RESULTS

SWE and CEUS combined showed the highest overall diagnostic performance (91% sensitivity, 77% specificity, 87% positive predictive value (PPV), 83% negative predictive value (NPV), 90% accuracy, χ2 (1) = 51.485, p < 0.001) compared to B-mode US and CCDS (87% sensitivity, 44% specificity, 73% PPV, 65% NPV, 73% accuracy χ2 (1) = 12.415, p < 0.001). In terms of individual techniques, SWE had higher specificity than B-mode and CCDS (71% sensitivity, 90% specificity, 92% PPV, 64% NPV, 78% accuracy, χ2 (1) = 36.115, p < 0.001), while qualitative CEUS showed the best diagnostic performance of all investigated US techniques (93% sensitivity, 85% specificity, 91% PPV, 87% NPV, 90% accuracy, χ2 (1) = 13.219, p < 0.001). Perfusion patterns, homogeneity, presence of necrosis, and malignancy differed significantly between malignant and benign CLNs (p < 0.001).

CONCLUSIONS

SWE and CEUS can facilitate the differentiation of inconclusive CLNs when performed to supplement B-mode US and CCDS. MpUS may thus aid the decision between surgery and a watch-and-scan strategy in enlarged CLNs.

Nomogram to differentiate benign and malignant thyroid nodules in the American College of Radiology Thyroid Imaging Reporting and Data System level 5

OBJECTIVES

To develop and validate a nomogram for differentiating benign and malignant thyroid nodules of American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) level 5 (TR5) and improving the performance of the guideline.

METHODS

From May 2018 to December 2019, 640 patients with TR5 nodules were retrospectively included in the primary cohort. Univariate and multivariable analyses were performed to determine the risk factors for thyroid cancer. A nomogram was established on the basis of multivariable analyses; the performance of the nomogram was evaluated with respect to discrimination, calibration, and clinical usefulness. The nomogram model was also compared to the ACR score model. External validation was performed and the independent validation cohort contained 201 patients from April 2021 to January 2022.

RESULTS

Multivariable analyses showed that age, tumour location, multifocality, concomitant Hashimoto's disease, neck lymph node status reported by ultrasound (US) and ACR score were the independent risk factors for thyroid cancer (all p < .05). The nomogram showed good discrimination, with an area under the curve (AUC) of 0.786 (95% confidence interval [CI]: 0.742-0.830) and 0.712 (95% CI: 0.615-0.809) in the primary cohort and external validation cohort, respectively. Decision curve analysis demonstrated the clinical usefulness of the model. Compared to the ACR score model, the nomogram showed higher AUC (0.786 vs. 0.626, p < .001) and specificity (0.783 vs. 0.391).

CONCLUSIONS

The presented nomogram model, based on age, tumour features and ACR score, can differentiate benign and malignant thyroid nodules in TR5 and had a high specificity.

Quantitative analysis of contrast-enhanced ultrasound combined with ultrasound in the unifocal papillary thyroid micro-carcinoma

OBJECTIVE

To evaluate diagnostic value of ultrasound (US) combined with contrast-enhanced ultrasound (CEUS) in the invasiveness of unifocal papillary thyroid micro-carcinoma (UPTMC) without capsule-invasion.

METHODS

This retrospective study included data from patients with UPTMC who received US and CEUS examinations in the Ultrasound Department of the Central Hospital of Changsha, China between June 2019 and September 2021. Univariate and multivariate logistic regression analysis were used to evaluate the risk of US and CEUS parameters for UPTMC. Diagnostic performance was estimated by ROC analysis.

RESULTS

A total of 136 cases were enrolled, including invasive UPTMC (n = 47) and non-invasive UPTMC (n = 89), which were divided into test set (n = 109) and validation set (n = 27). The occurrence of microcalcification and the ratios (R) of each time-intensity curve (TIC) of CEUS parameter were significantly higher in patients with invasive UTPMC than non-invasive UPTMC (all P < 0.05). Additionally, nodular diameter was significantly longer in the invasive group (P < 0.05). Multivariate analysis showed that microcalcification (OR = 2.917, 95% CI: 1.002-8.491, P = 0.050), R-TTP > 1 (OR = 3.376, 95%CI: 1.267-8.994, P = 0.015), R-DS > 1 (OR = 6.558, 95% CI: 2.358-18.243, P < 0.010) were independently associated with invasive UPTMC. The sensitivities of US, CEUS and their combined application were 82.1%, 46.2% and 79.5%, respectively, and their specificities were 37.1%, 88.6% and 61.4%, respectively. The combination of the two methods had the best diagnostic efficiency (AUC=0.775)compared to US (AUC = 0.596) and CEUS (AUC = 0.750).

CONCLUSION

The combination of US and CEUS might have good diagnostic value for UPTMC with capsule non-invasion.

Radiologist versus Non-Radiologist Detection of Lymph Node Metastasis in Papillary Thyroid Carcinoma by Ultrasound: A Meta-Analysis

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer worldwide and is known to spread to adjacent neck lymphatics. Lymph node metastasis (LNM) is a known predictor of disease recurrence and is an indicator for aggressive resection. Our study aims to determine if ultrasound sonographers’ degree of training influences overall LNM detection. PubMed, Embase, and Scopus articles were searched and screened for relevant articles. Two investigators independently screened and extracted the data. Diagnostic test parameters were determined for all studies, studies reported by radiologists, and studies reported by non-radiologists. The total sample size amounted to 5768 patients and 10,030 lymph nodes. Radiologists performed ultrasounds in 18 studies, while non-radiologists performed ultrasounds in seven studies, corresponding to 4442 and 1326 patients, respectively. The overall sensitivity of LNM detection by US was 59% (95%CI = 58–60%), and the overall specificity was 85% (95%CI = 84–86%). The sensitivity and specificity of US performed by radiologists were 58% and 86%, respectively. The sensitivity and specificity of US performed by non-radiologists were 62% and 78%, respectively. Summary receiver operating curve (sROC) found radiologists and non-radiologists to detect LNM on US with similar accuracy (p = 0.517). Our work suggests that both radiologists and non-radiologists alike detect overall LNM with high accuracy on US.

A Combination of Contrast-Enhanced Ultrasound and Thyroglobulin Level in Fine-Needle Aspirates Improves Diagnostic Accuracy for Metastatic Lymph Nodes of Papillary Thyroid Carcinoma

OBJECTIVE

To evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) combined with thyroglobulin (Tg) levels in fine-needle aspirates (FNA) washout fluid (FNA-Tg) in diagnosing cervical lymph node (LN) metastasis in papillary thyroid cancer (PTC) patients.

METHODS

Data from 190 LNs in 167 patients suspected of metastasis from the US between November 2018 and September 2020 were included. All subjects underwent FNA, CEUS, and FNA-Tg examinations. The final outcomes were confirmed by histopathological or cytological examination or follow-up imaging. Data were analyzed using the Wilcoxon rank-sum or chi-squared test. The diagnostic efficacy of FNA, CEUS, and FNA-Tg in diagnosing LNs was compared.

RESULTS

A cutoff value of 6.15 ng/ml (AUC 0.925, 95% confidence interval (CI) 0.885-0.966) successfully identified metastatic LNs. FNA missed 58 LN metastases, of these, 94.8% (55/58) were correctly diagnosed using the combination of CEUS and FNA-Tg. FNA-Tg showed higher sensitivity (90.2%), NPV (86.1%) and accuracy (88.9%) than either FNA (48.2, 57.4 and 69.5%, respectively) or CEUS (82.1, 67.7 and 70.5%, respectively) alone. The combination of CEUS, FNA and FNA-Tg resulted in maximal sensitivity (100%) and NPV (100%) but reduced specificity (51.3%) and overall diagnostic accuracy (80.0%). After adding FNA-Tg to discordant samples between CEUS and FNA, 81.9% of LNs (77/94) were correctly diagnosed.

CONCLUSIONS

The combination of FNA, FNA-Tg and CEUS was found to be a promising imaging tool in detecting metastatic LNs in PTC patients.

Early detection of suspicious lymph nodes in differentiated thyroid cancer

BACKGROUND

Early identification of cervical lymph node (LN) metastases cervical lymph node metastases (CLNM) is crucial in the management of differentiated thyroid cancer differentiated thyroid cancer (DTC) as it influences the indication and the extent of surgery with an impact on the recurrence risk and overall survival. The present review focused on novel sensitive and specific diagnostic techniques, by searching through online databases like MEDLINE and Scopus up to February 2022.

AREAS COVERED

The techniques identified included contrast-enhanced ultrasound (CEUS), dosage of fragment 21-1 of cytokeratin 19 (CYFRA 21-1) in lymph node fine needle aspiration washout, sentinel LN biopsy (SNB), and artificial intelligence (AI) - deep learning applied to ultrasonography and computed tomography. These methods displayed widely varying sensitivity and specificity results, ranging from approximately 60-100%. This variability is mainly due to the operator's experience because of the great complexity of execution of these new techniques, which require a long-learning curve.

EXPERT OPINION

Despite the appearance of many candidate methods to improve the detection of metastatic lymph nodes, none seem to be clearly superior to the tools currently used in clinical practice and FNA-Tg measurement remains the more accurate tool to detect neck recurrences and CLNM from DTC.

Contrast-enhanced ultrasound (CEUS) in characterization of inconclusive cervical lymph nodes: a meta-analysis and systematic review

Lymph node metastases are common in malignant neoplasms of head and neck. Since cervical lymph nodes (cLN) are localized superficially, ultrasound (US) represents the primary imaging modality. The aim of the study is to report the value of US and contrast-enhanced ultrasound (CEUS) and their diagnostic confidence in the characterization of inconclusive cLN. A systematic review was performed using the literature data base PubMed. Results were filtered (published in a peer-reviewed journal, full-text available, published within the last ten years, species human, English or German full-text) and inclusion criteria were clearly defined (cohort with lymphadenopathy or malignancy in head and neck ≥ 50 patients, histological confirmation of malignant imaging findings, performance of CEUS as outcome variable). The results were quantified in a meta-analysis using a random-effects model. Overall, five studies were included in qualitative and quantitative analysis. The combination of non-enhanced US and CEUS enlarges the diagnostic confidence in the characterization of lymph nodes of unclear dignity. The pooled values for sensitivity and specificity in the characterization of a malignant cervical lymph node using US are 76% (95%-CI 66-83%, I2 = 63%, p < 0.01) and 80% (95%-CI 45-95%, I2 = 92%, p < 0.01), compared to 92% (95%-CI 89-95%, I2 = 0%, p = 0.65) and 91% (95%-CI 87-94%, I2 = 0%, p = 0.40) for the combination of US and CEUS, respectively. Consistent results of the included studies show improved diagnostic performance by additional CEUS. Nevertheless, more prospective studies are needed to implement CEUS in the diagnostic pathway of cLN.

Value of contrast-enhanced ultrasound in predicting early lymph-node metastasis in oral cancer

OBJECTIVES

To explore the value of contrast-enhanced ultrasound (CEUS) in predicting early lymph node metastasis in clinically node-negative oral cancer patients.

METHODS

We recruited 42 patients (a total of 70 lymph nodes) with clinically node-negative oral cancer in the study. All of them received both conventional ultrasound (B-mode and power Doppler) and CEUS before operation and then they were taken for pathological examination to analyze the diagnostic accuracy. And their CEUS data were analyzed qualitatively and quantitatively.

RESULTS

The sensitivity and specificity of CEUS in the diagnosis of cervical lymph node metastasis of oral cancer were 82.7 and 82.9%, respectively. The accuracy of conventional ultrasound was only 67.1% while that of CEUS was up to 82.9%. The area under the cure (AUC) of CEUS in detecting lymph node metastasis was 0.828, which was higher than the 0.614 by conventional ultrasound, with statistically significant differences observed (p < 0.05). Most of the metastatic lymph nodes were characterized by inhomogeneous enhancement and the peak intensity (PI) of the metastatic group was lower than that of the non-metastatic group (p < 0.05).

CONCLUSIONS

Compared with conventional ultrasound, CEUS may have higher clinical value for predicting early lymph node metastasis in clinically node-negative oral cancer patients. And quantitative parameters obtained from CEUS may provide valuable information in the diagnosis of cervical lymph node metastasis.

Application of Preoperative Ultrasonography in the Diagnosis of Cervical Lymph Node Metastasis in Thyroid Papillary Carcinoma

Background

The clinical value and application of preoperative ultrasound contrast in the diagnosis of cervical lymph node metastasis in thyroid papillary carcinoma is investigated.

Methods

In total, 126 cases of thyroid papillary carcinoma were selected, the sensitivity and accuracy of color ultrasound and ultrasound contrast were analyzed by comparing preoperative gray-scale ultrasound, color ultrasound, and ultrasound contrast.

Results

The accuracies of preoperative color ultrasound and ultrasound contrast in detecting lymph node metastasis were 74 and 82%, respectively, and their sensitivities were 80 and 94%, respectively. Lymph node metastasis was significantly more severe when the tumor diameter was >4 cm. The lymphatic metastatic rate of the patients with multifocal papillary carcinoma was 96.4%, whereas the lymphatic metastatic rate of the patients with thyroid gland lesions was 87.7%. The central foci of cervical lymph node metastasis included the following pathological subtypes: diffuse sclerosis type (89.3%, 25/28), high-cell type (72.2%, 8/11), and papillary type (40.0%, 4/10).

Conclusion

Ultrasound contrast is more sensitive than color ultrasound in the diagnosis of cervical lymph node metastasis. Primary lesions ≥4 cm, lesion involvement, outer membrane, and high-risk pathologic subtypes and lesions were considered as the criteria for ultrasound contrast application.

Effectiveness of Lymphatic Contrast Enhanced Ultrasound in the diagnosis of Cervical Lymph node metastasis from papillary thyroid carcinoma

Cervical lymph node metastasis (CLNM) is common in patients with papillary thyroid carcinoma (PTC), which is responsible for tumor staging and surgical strategy. The accurate preoperative identification of CLNM is essential. In this study, twenty consecutive patients with PTC received a parenchyma injection of Sonazoid followed by contrast enhanced ultrasound (CEUS) to identify CLNM. The specific lymphatic CEUS (LCEUS) signs for diagnosing CLNM were summarized, which were further compared with the resected specimens to get the pathological basis. After the injection of contrast agent, lymphatic vessel and lymph node (LN) could be exclusively displayed as hyperperfusion on LCEUS. The dynamic perfusion process of contrast agent in CLNM over time can be clearly visualized. Perfusion defect and interruption of bright ring were the two characteristic LCEUS signs in diagnosing CLNM. After comparing with pathology, perfusion defect was correlated to the metastatic foci in medulla and interruption of bright ring was correlated to the tumor seeding in marginal sinus (all p values < 0.001). The diagnostic efficacies of these two signs were high (perfusion defect vs. interruption of bright ring: AUC, 0.899, 95% CI 0.752–1.000 vs. 0.904, 0.803–1.000). LCEUS has advantages in identifying CLNM from PTC. The typical LCEUS signs of CLNM correlated with pathology.

Diagnostic Test Accuracy of Ultrasonography vs Computed Tomography for Papillary Thyroid Cancer Cervical Lymph Node Metastasis: A Systematic Review and Meta-analysis

Importance

The use of ultrasonography (US) vs cross-sectional imaging for preoperative evaluation of papillary thyroid cancer is debated.

Objective

To compare thyroid US and computed tomography (CT) in the preoperative evaluation of papillary thyroid cancer for cervical lymph node metastasis (CLNM), as well as extrathyroidal disease extension.

Data Sources

MEDLINE and Embase were searched from January 1, 2000, to July 18, 2020.

Study Selection

Studies reporting on the diagnostic accuracy of US and/or CT in individuals with treatment-naive papillary thyroid cancer for CLNM and/or extrathyroidal disease extension were included. The reference standard was defined as histopathology/cytology or imaging follow-up. Independent title and abstract review (2515 studies) followed by full-text review (145 studies) was completed by multiple investigators.

Data Extraction and Synthesis

PRISMA guidelines were followed. Methodologic and diagnostic accuracy data were abstracted independently by multiple investigators. Risk of bias assessment was conducted using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool independently and in duplicate. Bivariate random-effects model meta-analysis and multivariable meta-regression modeling was used.

Main Outcomes and Measures

Diagnostic test accuracy of US and CT of the neck for lateral and central compartment CLNM, as well as for extrathyroidal disease extension, determined prior to study commencement.

Results

A total of 47 studies encompassing 31 942 observations for thyroid cancer (12 771 with CLNM; 1747 with extrathyroidal thyroid extension) were included; 21 and 26 studies were at low and high risk for bias, respectively. Based on comparative design studies, US and CT demonstrated no significant difference in sensitivity (73% [95% CI, 64%-80%] and 77% [95% CI, 67%-85%], respectively; P = .11) or specificity (89% [95% CI, 80%-94%] and 88% [95% CI, 79%-94%], respectively; P = .79) for lateral compartment CLNM. For central compartment metastasis, sensitivity was higher in CT (39% [95% CI, 27%-52%]) vs US (28% [95% CI, 21%-36%]; P = .004), while specificity was higher in US (95% [95% CI, 92%-98%]) vs CT (87% [95% CI, 77%-93%]; P < .001). Ultrasonography demonstrated a sensitivity of 91% (95% CI, 81%-96%) and specificity of 47% (95% CI, 35%-60%) for extrathyroidal extension.

Conclusions and Relevance

The findings of this systematic review and meta-analysis suggest that further study is warranted of the role of CT for papillary thyroid cancer staging, possibly as an adjunct to US.

Magnetic resonance imaging (MRI) radiomics of papillary thyroid cancer (PTC): a comparison of predictive performance of multiple classifiers modeling to identify cervical lymph node metastases before surgery

PURPOSE

To compare predictive efficiency of multiple classifiers modeling and establish a combined magnetic resonance imaging (MRI) radiomics model for identifying lymph node (LN) metastases of papillary thyroid cancer (PTC) preoperatively.

MATERIALS AND METHODS

A retrospective analysis based on the preoperative MRI scans of 109 PTC patients including 77 patients with LN metastases and 32 patients without metastases was conducted, and we divided enroll cases into trained group and validation group. Radiomics signatures were selected from fat-suppressed T2-weighted MRI images, and the optimal characteristics were confirmed by spearman correlation test, hypothesis testing and random forest methods, and then, eight predictive models were constructed by eight classifiers. The receiver operating characteristic (ROC) curves analysis were performed to demonstrate the effectiveness of the models.

RESULTS

The area under the curve (AUC) of ROC based on MRI texture diagnosed LN status by naked eye was 0.739 (sensitivity = 0.571, specificity = 0.906). Based on the 5 optimal signatures, the best AUC of MRI radiomics model by logistics regression classifier had a considerable prediction performance with AUCs 0.805 in trained group and 0.760 in validation group, respectively, and a combination of best radiomics model with visual diagnosis of MRI texture had a high AUC as 0.969 (sensitivity = 0.938, specificity = 1.000), suggesting combined model had a preferable diagnostic efficiency in evaluating LN metastases of PTC.

CONCLUSION

Our combined radiomics model with visual diagnosis could be a potentially effective strategy to preoperatively predict LN metastases in PTC patients before clinical intervention.

The Role of CEUS in the Evaluation of Thyroid Cancer: From Diagnosis to Local Staging

Ultrasound often represents the first diagnostic step for thyroid nodule evaluation in clinical practice, but baseline US alone is not always effective enough to achieve thyroid nodule characterization. In the last decades new ultrasound techniques, such as CEUS, have been introduced to evaluate thyroid parenchyma as recommended by EFSUMB guidelines, for use in clinical research field, although its role is not yet clear. Several papers show the potential utility of CEUS in the differential diagnosis of benign and malignant thyroid nodules and in the analysis of lymph node involvement in neoplastic pathology. Therefore, we carried out an evaluation of the literature concerning the role of CEUS in three specific areas: the characterization of the thyroid nodule, the evaluation of minimally invasive treatment and loco-regional staging of the lymph node in proven thyroid cancer. According to evidence reported, CEUS can also play an operative role in nodular thyroid pathology as it is able to guide ablation procedures on thyroid nodule and metastatic lymph nodes, to assess the radicality of surgery, to evaluate disease relapse at the level of the margins of ablated regions and to monitor the clinical evolution of necrotic areas in immediate post-treatment setting.

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.

Combination of Lymphatic and Intravenous Contrast-Enhanced Ultrasound for Evaluation of Cervical Lymph Node Metastasis from Papillary Thyroid Carcinoma: A Preliminary Study

The aim of this prospective study was to evaluate the value of the combination of lymphatic contrast-enhanced ultrasound (LCEUS) and intravenous contrast-enhanced ultrasound (IVCEUS) for the identification of cervical lymph node metastasis (CLNM) from papillary thyroid carcinoma (PTC). From November 2018 to March 2019, 24 consecutive patients with PTC were evaluated. All patients underwent routine US, LCEUS and IVCEUS. Pathology was used as the gold standard. After injection of a contrast agent into the thyroid parenchyma, lymphatic vessels and lymph nodes (LNs) could be exclusively displayed as hyper-enhancement on LCEUS. Benign LNs displayed a complete bright ring (100%) and homogeneous perfusion (88.9%) on LCEUS, while displaying centrifugal perfusion (66.7%) and homogenous enhancement (88.9%) on IVCEUS. Perfusion defects (94.9%) and interruption of the bright ring (71.8%) were the two characteristic LCEUS signs for diagnosing CLNM. On IVCEUS, CLNM appeared as centripetal perfusion (59.0%) and heterogeneous enhancement (59.0%). After comparison with pathology, perfusion defect was correlated to the metastatic foci in the medulla and interruption of the bright ring to the tumor seeding in the marginal sinus (all p values <0.05). LCEUS had more value (area under the receiver operating characteristic curve [AUC] = 0.850, 95% confidence interval [CI]: 0.682-1.000) in diagnosing CLNM than IVCEUS (AUC = 0.692, 95% CI: 0.494-0.890) and routine US (AUC = 0.581, 95% CI: 0.367-0.796). The combination of LCEUS and IVCEUS has the highest diagnostic value (AUC = 0.863, 95% CI: 0.696-1.000). LCEUS had higher diagnostic value than IVCEUS and US for CLNM from PTC. The combination of LCEUS and IVCEUS has the highest diagnostic value for CLNM.

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

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

Ultrasound and Contrast-Enhanced Ultrasound Characteristics Associated With cN1 and Microscopic pN1 in Papillary Thyroid Carcinoma

OBJECTIVES

Lymph node metastases (LNMs) could be stratified into clinical N1 (cN1) and microscopic pN1 (pathological N1), which bear different biological behavior and prognosis. Our study aimed to investigate the associations between LNMs and primary tumor's US (ultrasound) and CEUS (contrast-enhanced ultrasound) characteristics based on the stratification of LNMs into cN1 and microscopic pN1 in papillary thyroid carcinoma (PTC).

METHODS

From August 2019 to May 2020, 444 consecutive PTC patients who underwent preoperative neck US and CEUS evaluation were included. According to regional lymph node status, the patients were classified into cN1 group versus cN0 (clinical N0) group and microscopic pN1 group versus pN0 (pathological N0) group. For multiple PTCs, the largest one was selected for the evaluation of US, CEUS and clinical features. Univariate and multivariate analyses were performed to determine independent predictors of cN1 and microscopic pN1.

RESULTS

85 cN1 versus 359 cN0 patients and 117 microscopic pN1 versus 242 pN0 patients were analyzed. Multivariate logistic regression analysis showed that <55-years-old (OR: 2.56 (1.08-6.04), male [OR: 2.18 (1.22-3.91)], large size [OR: 2.59 (1.71-3.92)], calcification [OR: 3.88 (1.58-9.51)], and hyper-enhancement [OR: 2.78 (1.22-6.30)] were independent risk factors of cN1, while <55-years-old [OR: 1.91 (1.04-3.51)], large size [OR: 1.56 (1.003-2.42)], multifocality [OR: 1.67 (1.04-2.66)] were independent risk factors of microscopic pN1.

CONCLUSIONS

For patients with PTC, young age, male, large size, calcification, and hyper-enhancement were independent predictors of cN1, while young age, large size and multifocality were independent predictors of microscopic pN1.

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.

Clinical applications of Doppler ultrasonography for thyroid disease: consensus statement by the Korean Society of Thyroid Radiology

Doppler ultrasonography (US) is widely used for the differential diagnosis of thyroid nodules, metastatic cervical lymph nodes in patients with thyroid cancer, and diffuse parenchymal disease, as well as for guidance in various US-guided procedures, including biopsy and ablation. However, controversies remain regarding the appropriate use and interpretation of Doppler US. Therefore, the Korean Society of Thyroid Radiology organized a taskforce to develop a consensus statement on the clinical use of Doppler US for thyroid disease. The review and recommendations in this article are based on a comprehensive analysis of the current literature and the consensus of experts.

Comparison of contrast-enhanced ultrasound and contrast-enhanced computed tomography for the diagnosis of cervical lymph node metastasis in squamous cell carcinoma of the oral cavity

Early detection of cervical lymph node metastasis (CLNM) from squamous cell carcinoma (SCC) of the oral cavity remains challenging. This prospective study was performed to evaluate the ability of contrast-enhanced ultrasound (CEUS) to detect CLNM from oral cavity SCC. Additionally, its diagnostic value was compared with that of contrast-enhanced computed tomography (CECT). Forty-eight consecutive patients with SCC of the oral cavity were enrolled. All subjects were examined preoperatively with both CEUS and CECT. Subsequently, neck dissections were performed for these patients, and cervical lymph nodes separated from the surgical specimens were assessed histologically. The diagnostic performance of these two examinations was compared based on the results of histopathology. The sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and Youden index for CEUS and CECT were 69.39% vs. 44.90%, 94.71% vs. 97.12%, 89.88%% vs. 87.16%, 75.56% vs. 78.57%, 92.92% vs. 88.21%, and 64.10% vs. 42.02%, respectively. A significant difference was observed in terms of sensitivity (P=0.024) and Youden index (rate difference 22.08%, 95% confidence interval 2.72-41.44%). Therefore, CEUS appears to be a promising diagnostic tool that is superior to CECT for detecting CLNM from SCC of the oral cavity, with a higher sensitivity.

A comparative study of short-term efficacy and safety for thyroid micropapillary carcinoma patients after microwave ablation or surgery

Background: Although papillary thyroid microcarcinoma (PTMC) has a high incidence and excellent clinical outcome, debate continues as to the therapeutic approach that would be most appropriate after confirming the diagnosis. Methods: We retrospectively analyzed the medical records of 311 patients with T1aN0M0 PTMC between January 2013 and September 2018. In all, 168 underwent microwave ablation (MWA), and 143 underwent surgery. MWA was performed using extensive ablation with hydrodissection. The surgery comprised thyroid lobectomy (TL) with unilateral central lymph node dissection (CND). We examined clinical outcomes during mean follow-up periods of 824 ± 452 days for the TL group and 753 ± 520 days for the MWA group. Results: Postprocedural follow-up revealed that, in the MWA group, the tumors had completely disappeared in 34 patients, and the remainder were reduced to necrotic or carbonized tissue. The incidence of transient hypoparathyroidism was significantly lower in the MWA group than in the TL group (p < .001). In addition, during the follow-up, we found no statistically significant differences between the two groups (TL vs MWA) for PTMC recurrence (1 vs 2 cases), lymph node metastasis (5 vs 5 cases), or disease-free survival [2001 days (5.5 years) vs 1702 days (4.7 years)] (p = .659, p = .795, and p = .974, respectively). Conclusions: If low-risk thyroid carcinoma (i.e., T1N0M0 PTMC) is accurately diagnosed early, MWA could be a minimally invasive alternative to surgery based on our short-term follow-up regarding recurrence and the low rates of complications and disease-free survival.

Homogeneity Parameter in Contrast-Enhanced Ultrasound Imaging Improves the Classification of Abnormal Cervical Lymph Node after Thyroidectomy in Patients with Papillary Thyroid Carcinoma

Objective

To explore the conventional and contrast-enhanced ultrasound (CEUS) features of cervical lymph node metastasis (CLNM) in papillary thyroid carcinoma (PTC) patients postoperatively and analyze its pathological basis.

Materials and Methods

Conventional and CEUS were performed in 86 abnormal cervical lymph nodes (ACLNs) from 56 PTC patients who had received thyroidectomy. Then, fine-needle aspiration (FNA) was taken to confirm pathological results, a multivariate analysis was performed to correlate the sonographic features of the CLNM, and then an equation for CLNM was established.

Results

Fifty-four lymph nodes were confirmed to be metastasis of PTC by FNA. Intensity at peak time, homogeneity, and color flow patterns, cystic change, or microcalcification and echogenicity were significantly associated with CLNM. Multivariate analysis showed three strongest features (homogeneity, intensity of peak, and cystic change or calcification) to be significantly associated with the evidence of CLNM. Then, the equation was established with the following significant predictive factors: P = 1/1 + exp∑[−3.213 + 2.77 ∗ cystic or calcification + 0.13 ∗ CDFI patterns + 3.65 ∗ homogeneity + 2.43 ∗ intensity at peak time].

Conclusion

Depiction of a heterogeneous hyperenhancement of cervical lymph nodes within CEUS studies and cystic change or microcalcification in conventional ultrasound were identified as predictive for metastatic lymph node invasion, and the equation was more accurate for predicting CLNM compared to single B-mode ultrasound and CEUS feature.

Predicting cervical lymph node metastasis in patients with papillary thyroid cancer (PTC) - Why contrast-enhanced ultrasound (CEUS) was performed before thyroidectomy

The objective of this research was to investigate the clinical value of contrast-enhanced ultrasound (CEUS) for prediction of cervical lymph node metastasis (CLNM) in papillary thyroid cancer (PTC).One hundred and eighty-six patients with PTC confirmed by fine needle aspiration (FNA) were preoperatively performed CEUS.A multivariate analysis was performed to predict CLNM by 15 independent variables. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance.There were totally 37 patients with CLNM confirmed by pathology. Multivariate analysis demonstrated that intensity at peak time, capsule contact and size on CEUS were the three strongest independent predictors for CLNM. ROC analyses of these characteristics showed the areas under the curve (Az), sensitivity, and specificity were 0.650, 48.6 %, 79.8 %; 0.586, 67.6%, 49.7%; and 0.612, 56.8%, 64.4% for intensity at peak time, capsule contact, and size, respectively.The CEUS patterns of PTC are relative to not only the size of PTC but also the possibility of CLNM after thyroidectomy. CEUS seem to be a tool to predict CLNM in PTC patients.

Value of contrast-enhanced ultrasound combined with elastography in evaluating cervical lymph node metastasis in papillary thyroid carcinoma

BACKGROUND

Cervical lymph node metastasis in papillary thyroid carcinoma (PTC) affects the treatment and prognosis of patients. Ultrasound is a common imaging method for detecting cervical lymph nodes in PTC patients; however, it is not accurate in determining lymph node metastasis.

AIM

To evaluate the value of contrast-enhanced ultrasound combined with elastography in evaluating cervical lymph node metastasis in PTC.

METHODS

A total of 94 patients with PTC were recruited. According to pathological results, lymph nodes were divided into two groups: metastatic group (n = 50) and reactive group (n = 63). The routine ultrasound findings, contrast-enhanced ultrasound and elastography data were recorded and compared. Logistic regression was used to generate predictive probability distributions for the diagnosis of lymph node metastasis with different indicators. Receiver operating characteristic curve analysis was used to test the efficacy of contrast-enhanced ultrasound combined with elastography based on routine ultrasound in evaluating PTC cervical lymph node metastasis.

RESULTS

The ratio of long diameter/short diameter (L/S) ≤ 2, irregular marginal morphology, missing lymphatic portal, peripheral or mixed blood flow distribution, peak intensity (PI), non-uniform contrast distribution and elasticity score in the metastatic group were significantly higher than those in the reactive group (P < 0.05). L/S ratio, missing lymphatic portal, PI and elasticity score had a significant influence on the occurrence of PTC cervical lymph node metastasis (P < 0.05). Furthermore, the area under the curve (AUC) for lymph node metastasis diagnosed using the combination of PI ratio, elasticity score, missing lymphatic portal and LS was 0.936, which was significantly higher than the AUC for PI ratio alone. The difference was statistically significant (P < 0.05). The fitting equation for the combined diagnosis was logit(P) = -12.341 + 1.482 × L/S ratio + 3.529 × missing lymphatic portal + 0.392 × PI + 3.288 × elasticity score.

CONCLUSION

Based on the gray-scale ultrasound, the combination of contrast-enhanced ultrasound and elastography can accurately assess PTC cervical lymph node metastasis.

Application of contrast-enhanced ultrasound for evaluation of thyroid nodules

Contrast-enhanced ultrasound (CEUS) is widely used to evaluate tumor microcirculation, which is useful in the differential diagnosis between benignity and malignancy. In the last 10 years, the applicability of CEUS to thyroid nodules has greatly improved due to technological refinements and the development of second-generation contrast agents. In this review, we summarize the applications of CEUS for thyroid nodules, focusing on the imaging findings of malignant and benign nodules in the existing literature and the use of those findings to predict malignancies, with an additional brief description of the utilization of CEUS for other thyroid-related diseases.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Contrast-enhanced ultrasonography features of papillary thyroid carcinoma for predicting cervical lymph node metastasis

The present study was performed to evaluate the predictive value of contrast-enhanced ultrasonography (CEUS) for the risk of cervical lymph node metastasis (LNM) in papillary thyroid carcinoma (PTC). Between May 2014 and November 2016, 42 patients who received surgery for suspicious PTCs were enrolled in the present study. Each individual underwent CEUS with conventional ultrasound (US), preoperative US-guided fine needle aspiration and personalized surgery. Subsequently, the microvascular density (MVD) of all surgical specimens was measured. According to the results of surgical histopathology, individuals were divided into two groups: LNM⁺ (PTCs with LNM), and LNM⁻ (PTCs without LNM). Clinicopathological characteristics, CEUS enhancement patterns, perfusion parameters and measurements of MVD were compared. The correlation between quantitative variables and LNM was analyzed using Spearman's correlation analysis. Compared with that in the LNM⁻ group, patients in the LNM⁺ group were younger (P<0.05) and had a larger mean tumor size (P<0.05). The incidence ratio of patients who were ≤45 years old (P<0.05), tumors >10 mm in size (P<0.05) and capsular infiltration (P<0.05) were statistically higher in the LNM⁺ group. Following the use of a novel classification system, the ratio of PTCs with early partial hyper-enhancement was identified to be significantly higher in the LNM⁺ group (P<0.01). The mean intensity, intensity increase velocity, MVD ratio and mean intensity ratio of intratumoral/peripheral thyroid parenchyma (MIR) were statistically higher in the LNM⁺ group compared with that in the LNM⁻ group (all P<0.05). MIR was identified to be positive correlated with LNM (P<0.05). A MIR value of 0.86 was the optimal threshold of LNM in PTCs. In conclusion, LNM may rely on the local rich blood supply of PTC lesions. Partial hyper-enhancements of CEUS and higher values of MIR may suggest a high risk for LNM in PTC.

Monitoring of Blood Vessel Density Using Contrast-Enhanced High Frequency Ultrasound May Facilitate Early Diagnosis of Lymph Node Metastasis

Time-dependent alterations in the ultrasonography characteristics of lymph nodes during early-stage metastasis have not been compared with those of tumor-draining lymph nodes that do not develop tumor; this is partly due to the absence of an appropriate experimental model. In a previous study of lymph nodes with experimental early-stage metastasis, we used contrast-enhanced high-frequency ultrasound to demonstrate that an increase in lymph node blood vessel density preceded any changes in lymph node volume. In the present study, we used an experimental model of lymph node metastasis in which tumor cells metastasized from the subiliac lymph node to the proper axillary lymph node (the tumor-draining lymph node). We utilized contrast-enhanced high-frequency ultrasound to perform a longitudinal analysis of tumor-draining lymph nodes, comparing those at an early-stage of metastasis with those that did not develop detectable metastasis. We found that the normalized blood vessel density of an early-stage metastatic lymph node exhibited a progressive rise, whereas that of a tumor-draining lymph node not containing tumor began to increase later. For both types of lymph nodes, the normalized blood vessel density on the final day of experiments showed a trend towards being higher than that measured in controls. We further found that mice with an initially low value for lymph node blood vessel density subsequently showed a larger increase in the blood vessel density of the metastatic lymph node; this differed significantly from measurements in controls. The present study indicates that a longitudinal analysis of the blood vessel densities of tumor-draining lymph nodes, made using contrast-enhanced high-frequency ultrasound imaging, may be a potentially promising method for detecting early-stage lymph node metastasis in selected patients. Furthermore, our findings suggest that tumor in an upstream lymph node may induce alteration of the vascular structures in draining lymph nodes that do not contain tumor.

Diagnostic accuracy of ultrasonographic features for lymph node metastasis in papillary thyroid microcarcinoma: a single-center retrospective study

Background

Whether sonography is an appropriate imaging modality for cervical lymph nodes in patients with papillary thyroid microcarcinoma (PTMC) remains unclear. Hence, this study aimed to evaluate the diagnostic value of ultrasonography (US) features for lymph node metastasis in PTMC.

Methods

Seven hundred twelve patients with PTMC who underwent conventional ultrasonography examinations of the cervical lymph nodes were included. All included cases underwent total thyroidectomy plus prophylactic central lymph node dissection. The included lymph nodes were marked superficially, and the corresponding lymph nodes were completely removed and sent for pathological examination. The US features of lymph nodes with and without metastasis were compared, and the odds ratios of the suspicious US features were determined with univariate and multivariate analyses.

Results

Round shape, loss of an echogenic fatty hilum, cystic change, calcification, and abnormal vascularity were significantly more common in metastatic than nonmetastatic lymph nodes, whereas the boundary and echo did not significantly differ. Multivariate logistic regression analysis showed that round shape, loss of echogenic fatty hilum, cystic change, calcification, and abnormal vascularity were independent predictive factors for the assessment of metastatic lymph nodes. Round shape had the highest sensitivity of all variables, while loss of an echogenic fatty hilum had the highest specificity and accuracy. The area under the receiver operating characteristic curve, which was calculated to verify the relationship between the various US features and metastatic lymph nodes, was 0.793.

Conclusions

Our study found that the US features of round shape, cystic change, calcification, loss of echogenic fatty hilum, and abnormal vascularity were useful sonographic criteria for differentiating between cervical lymph nodes with and without metastasis.

Role of contrast-enhanced endoscopic ultrasound in lymph nodes

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

Prediction of cervical lymph node metastasis in patients with papillary thyroid cancer using combined conventional ultrasound, strain elastography, and acoustic radiation force impulse (ARFI) elastography

OBJECTIVES

To investigate the value of combined conventional ultrasound (US), strain elastography (SE) and acoustic radiation force impulse (ARFI) elastography for prediction of cervical lymph node metastasis (CLNM) in papillary thyroid cancer (PTC).

METHODS

A consecutive series of 203 patients with 222 PTCs were preoperatively evaluated by US, SE, and ARFI including virtual touch tissue imaging (VTI) and virtual touch tissue quantification (VTQ). A multivariate analysis was performed to predict CLNM by 22 independent variables. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance.

RESULTS

Multivariate analysis demonstrated that VTI area ratio (VAR) > 1 was the best predictor for CLNM, followed by abnormal cervical lymph node (ACLN), capsule contact, microcalcification, capsule involvement, and multiple nodules (all P < 0.05). ROC analyses of these characteristics showed the areas under the curve (Az), sensitivity, and specificity were 0.600-0.630, 47.7 %-93.2 %, and 26.9 %-78.4 % for US, respectively; and they were 0.784, 83.0 %, and 73.9 %, respectively, for VAR > 1. As combination of US characteristics with and without VAR, the Az, sensitivity, and specificity were 0.803 and 0.556, 83.0 % and 100.0 %, and 77.6 % and 11.2 %, respectively (P < 0.001).

CONCLUSIONS

ARFI elastography shows superior performance over conventional US, particularly when combined with US, in predicting CLNM in PTC patients.

KEY POINTS

• Conventional ultrasound is useful in predicting cervical lymph node metastasis preoperatively. • Virtual touch tissue imaging area ratio is the strongest predicting factor. • Predictive performance is markedly improved by combining ultrasound characteristics with VAR. • Acoustic radiation force impulse elastography may be a promising complementary tool.

Feasibility of Charcoal Tattooing for Localization of Metastatic Lymph Nodes in Robotic Selective Neck Dissection for Papillary Thyroid Carcinoma

BACKGROUND

This study aimed to evaluate the feasibility and effectiveness of ultrasound-guided charcoal tattooing in locating metastatic lymph nodes in robotic selective neck dissection (SND) for papillary thyroid carcinoma (PTC).

METHODS

The overall study group comprised 21 patients with PTC who underwent robotic SND via a unilateral transaxillary approach for treatment of suspicious lymph node metastasis in the lateral compartment. Charcoal suspension was injected into 10 of the patients (total of 23 lesions) 1 day before robotic SND. The authors evaluated the location of the tattoos, the success rate of localization, the intraoperative detection rate, and the complications associated with the procedure. The perioperative results were compared with those in the control group of 11 patients who did not receive charcoal tattooing.

RESULTS

Charcoal suspension was successfully injected into 22 of the 23 suspicious lymph nodes (95.7 %). The remaining lesion was located posterior to the internal jugular vein. Therefore, the charcoal was injected into the soft tissue around the lymph node. Ultrasound-guided injections were well tolerated in all the patients, and no major complications occurred. All the charcoal-tattooed lesions were identified intraoperatively by the surgeon. The number of harvested and metastatic lymph nodes in the lateral compartment was greater in the patients with charcoal tattoo localization than in the control group. The two groups did not differ in terms of perioperative complications, operation time, or volume of drainage.

CONCLUSION

Ultrasound-guided charcoal tattooing for localization of metastatic lymph nodes is feasible and effective in robotic SND for the treatment of PTC with lateral compartment lymph node metastasis.