Contrast-enhanced color Doppler sonography for evaluation of enlarged cervical lymph nodes in head and neck tumors

Ultrasound in head and neck surgery: thyroid, parathyroid, and cervical lymph nodes

Ultrasound (US) of the neck is extremely sensitive in detecting thyroid, parathyroid, and cervical lymph node pathology, and is regarded as the most complete and cost-effective imaging method for evaluating the thyroid and parathyroid glands, as well as for the diagnostic evaluation of the cervical lymph node basin. US is widely used in screening high-risk individuals, evaluation of palpable and nonpalpable thyroid nodules, needle guidance for biopsy of nonpalpable and suspicious nodules, and preoperative evaluation of the extent of thyroid neoplasms, as well as in the detection of residual, recurrent, or metastatic thyroid tumors, and in observing nonsurgical cases. It has thus become an important adjunct to the practice of head and neck surgery.

Does ultrasound contrast agent improve the diagnostic value of colour and power Doppler sonography in superficial lymph node enlargement?

OBJECTIVE

to analyse whether ultrasound contrast agent (UCA) improves the diagnostic accuracy to differentiate between benign and malignant superficial lymph node enlargement by using colour-coded duplex sonography (CCDS) and power Doppler (PD).

METHODS

32 patients with suspected malignant superficial lymph node enlargement prospectively underwent standardised ultrasound examinations using B-mode sonography and native and contrast-enhanced CCDS and PD immediately before biopsy. Solbiati-Index (longitudinal-transverse diameter ratio) and intranodal flow patterns by using different vascularisation types were assessed. Histological and sonographical findings were correlated.

RESULTS

27 malignant and 5 benign lymph nodes were found. Solbiati-Index was lower in malignant lymph nodes than in benign nodes (mean 1.5 vs. 2.4, P<0.045). More intranodal flow patterns could be detected after UCA (53 vs. 43) but the number of correctly identified malignant nodes decreased after UCA (26 vs. 24) and the number of correctly identified benign nodes remained constant compared with native CCDS and PD. In 31% of the colour-mode studies, PD was considered to visualise more clearly intranodal vascular flow patterns than CCDS.

CONCLUSION

despite depicting more intranodal vascular patterns, the use of an ultrasound contrast agent seems not to improve the diagnostic value of CCDS and PD compared with native colour-mode studies in superficial lymph node enlargement.

Evaluation of lymph node perfusion using continuous mode harmonic ultrasonography with a second-generation contrast agent

OBJECTIVE

To evaluate the contribution of continuous mode contrast-enhanced harmonic ultrasonography (CE-HUS) with a second-generation contrast agent to the characterization of superficial lymphadenopathies with respect to conventional ultrasonographic techniques (B-mode and power Doppler).

METHODS

Fifty-six lymph nodes from 45 patients were studied both by conventional techniques and by CE-HUS. The dimensions, intranodal architecture, margins, and location of vessels were evaluated. Subsequently, all the lymph nodes were examined by CE-HUS, and enhancement of echogenicity was evaluated. The diagnoses obtained by means of fine-needle aspiration cytologic examination, surgical biopsy, or both were compared with those obtained by ultrasonography.

RESULTS

Of the lymph nodes examined, 30 were benign and 26 were malignant (18 metastases and 8 non-Hodgkin lymphomas). The study using CE-HUS showed intense homogeneous enhancement in 28 of 30 reactive lymph nodes; perfusion defects in 17, of which 15 were neoplastic and 2 were inflammatory; intense but inhomogeneous speckled enhancement in the early arterial phase in 5 cases of lymphoma; and, last, scarce or absent intranodal enhancement in 4 metastases. The specificity, sensitivity, and accuracy of conventional techniques in differentiation between benign and malignant lymph nodes were 76%, 80%, and 78% versus 93%, 92%, and 92.8% for CE-HUS. The increase in correct diagnoses was significant (P = .05) when conventional ultrasonography was tested against CE-HUS.

CONCLUSIONS

Superficial lymph nodes can be characterized as being neoplastic or benign with a high degree of diagnostic accuracy on the basis of the perfusion characteristics evaluated by CE-HUS. This technique has been shown to afford a higher degree of accuracy than currently obtainable by any other ultrasonographic technique.

Imaging the lymphatic system: possibilities and clinical applications

The lymphatic system is anatomically complex and difficult to image. Lymph ducts are responsible for the drainage of part of the body's interstitial fluid. Lymph nodes account for the enrichment of lymph fluid, and can be involved in a large variety of diseases, especially cancer. For a long time, lymphatic imaging was limited to the sole use of conventional lymphography involving invasive procedures and patient discomfort. New contrast agents and techniques in ultrasound, nuclear medicine, and MR imaging are now available for imaging of both the lymphatic vessels and the lymph nodes. The objective of this review is to discuss the different imaging modalities of the lymphatic system, with a special focus on the new possibilities of lymphatic imaging including enhanced MR lymphography, sentinel node and positron emission tomography imaging, and contrast-enhanced ultrasound.

Sonography of neck lymph nodes. Part II: abnormal lymph nodes

Assessment of cervical lymph nodes is essential for patients with head and neck carcinomas, and ultrasound is a useful imaging technique. Sonographic features that help distinguish between the causes of neck lymphadenopathy, including grey scale and Doppler features, are discussed. In addition to the distribution and location of nodes, the useful grey-scale features are: size, shape, internal architecture, intranodal necrosis, absence of hilar structure and calcification. The useful Doppler features are: distribution of vascularity and intranodal resistance. Ancillary features such as oedema of soft tissue and nodal matting are particularly helpful to identify tuberculous nodes.

Cystic appearance of cervical lymph nodes is characteristic of metastatic papillary thyroid carcinoma

PURPOSE

The usefulness of high-resolution sonography in diagnosing cervical lymph node metastases from papillary thyroid carcinoma was investigated. The accuracy of a particular sign, cystic change within a node, in establishing the diagnosis was assessed.

METHODS

The sonographic findings in 63 patients with enlarged cervical lymph nodes were retrospectively reviewed. The patients had undergone high-resolution gray-scale and color Doppler sonography followed by ultrasound-guided fine-needle aspiration (FNA) in all patients and surgical excision in 27 patients.

RESULTS

Abnormal sonographic features were present in the lymph nodes of all 63 patients. In 14 (70%) of 20 patients with papillary thyroid carcinoma, sonography depicted cystic changes. This pattern was not found in any of the other 43 patients, in whom FNA revealed either metastasis from another malignancy (22 patients) or benign reactive lymphadenopathy (21 patients). Among the 63 patients, there were 43 true-negative, 14 true-positive, 6 false-negative, and no false-positive results in the diagnosis of metastatic papillary thyroid carcinoma using the presence or absence of an intranodal cystic area on sonography. These results yielded a 70% sensitivity, 100% specificity, 100% positive predictive value, 88% negative predictive value, and 90% overall accuracy for this criterion.

CONCLUSIONS

Cystic changes within a cervical lymph node are highly suggestive of metastatic papillary thyroid carcinoma.

Volume of cervical lymph nodes using 3D ultrasonography. Differentiation of metastatic from reactive lymphadenopathy in primary head and neck malignancy

PURPOSE

To assess the usefulness of volume measurement using 3D US for depicting metastatic cervical lymph nodes.

MATERIAL AND METHODS

Thirty-five cervical lymph nodes in 13 patients with primary head and neck malignancy were included in this study. US with volume acquisition was prospectively performed with a 5-10 MHz linear mechanical volume probe. Volume measurement of the node was calculated using a 3D automatic volume calculation program. The excised nodes matched on US were examined histopathologically.

RESULTS

The volume of malignant nodes ranged from 0.444 to 4.442 cm3, the volume of the benign nodes from 0.143 to 1.176 cm3. Combinations of high positive (>80%) and negative (>90%) predictive values were obtained at a cut-off value of 0.7 cm3.

CONCLUSION

Volume measurement of cervical nodes using 3D US can be a useful tool for differentiating metastatic from benign nodes in patients with primary head and neck malignancy.

Sonography of soft tissue masses of the neck

In many clinical conditions, high-resolution sonography and color (power) Doppler sonography can be used as the first-line modality for evaluating cervical soft tissue masses. Cervical cysts, lipomas, paragangliomas, neurogenic tumors, hemangiomas, and lymphangiomas often exhibit characteristic sonographic appearances. Sonography can be used for lymph node assessment, and most salivary gland diseases can be diagnosed sonographically. Sonography can be used to guide needle biopsy of soft tissue neoplasms and lymph nodes. In addition, the relationship between a cervical mass and the great vessels can be evaluated.

Color Doppler sonography in the evaluation of superficial lymphomatous lymph nodes

OBJECTIVE

We performed a retrospective study to document the sonographic and color Doppler characteristics of lymphomatous superficial lymph nodes.

METHODS

We selected 130 individuals who underwent sonography, color Doppler imaging, fine-needle aspiration biopsy, and surgical removal of the nodes with the final diagnosis of lymphoma (87) and chronic adenitis (43). During sonography, for each node we considered the longitudinal and axial diameters, long/short axis ratio, visibility of the hilum, and the internal echogenicity of the node. During the color and power Doppler examination, we classified the nodes into 3 patterns: type I, "hilar normal"; type II, "hilar activated"; and type III, "peripheral."

RESULTS

Sonographic evidence was not significant. With color Doppler sonography, 97% of nodes affected by non-Hodgkin lymphoma, 94% of nodes affected by Hodgkin lymphoma, and 100% of non-neoplastic nodes showed hilar vascularity. Type I seemed more frequently associated with inflammation, and type II was more frequently associated with lymphoma.

CONCLUSIONS

The presence of peripheric subcapsular vessels, which is typical of metastasis, is definitely rare in lymphoma (with the possible exception of the uncommon subtypes of high-grade lymphomas). The differential diagnosis between lymphoma and lymphadenitis is frequently impossible on the basis of sonographic and color Doppler patterns alone; therefore, clinical evaluation and biopsy are generally mandatory.

Ultrasound-guided biopsy and ablation in the neck

Management and therapy of conditions of the thyroid, parathyroid glands, and cervical lymph nodes have evolved rapidly during the past 15 years. The development and continued improvement of high-resolution ultrasound (US) equipment, US-guided biopsy, and image-guided ablative techniques have fueled this change. These technical improvements and the knowledge and experience gained during this time have decreased the rate of unnecessary surgery in patients with thyroid nodules. They have also allowed more limited neck dissection in patients with parathyroid adenomas and have led to the development of US-guided ablative techniques that have eliminated the need for surgery in some cases. This article reviews the rationale and techniques of US-guided biopsy of the thyroid, parathyroid, and cervical lymph nodes. Established and evolving ablative techniques of these structures are also examined.