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.
Rubaltelli
Leopoldo
L
Department of Medical Diagnostic Sciences and Special Therapies, University of Padua, Padua, Italy. leopoldo.rubaltelli@unipd.it
Khadivi
Yeganeh
Y
Tregnaghi
Alberto
A
Stramare
Roberto
R
Ferro
Federica
F
Borsato
Simonetta
S
Fiocco
Ugo
U
Adami
Fausto
F
Rossi
Carlo Riccardo
CR
D000328:Adult; D000368:Aged; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008206:Lymphatic Diseases / Q000000981:diagnostic imaging; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010743:Phospholipids; D013459:Sulfur Hexafluoride; D014463:Ultrasonography / Q000379:methods
D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride