Background and study aims: Ultrasonographic elastography is a new technique for describing the mechanical properties of tissue during real-time ultrasonography. The aim of this study was to test the feasibility of this method in endosonography (EUS) of the dorsal mediastinum, and to compare the elastographic patterns of lymph nodes with results from EUS-guided fine-needle aspiration biopsy (FNAB).
Patients and methods: 50 consecutive patients undergoing EUS-guided FNAB of at least one paraesophageal lymph node were included. Each of these targeted lymph nodes was examined also elastographically. The elastographic patterns were described and compared with the histologic results by a first examiner. The elastographic classification was subsequently further tested by two blinded reviewers.
Results: In total, 66 lymph nodes were examined; 37 lymph nodes revealed benign and 29 malignant tissue at the histologic evaluation. Good elastographic records were obtained for all lymph nodes. Of the 37 benign lymph nodes, 31 showed a homogeneous pattern of intermediate elasticity, whereas a dominance of hard tissue with variable patterns was found in 23 of 29 malignant lymph nodes. Applying these criteria, the accuracy range among the three examiners was between 81.8 % and 87.9 % for benign lymph nodes and between 84.6 % and 86.4 % for malignant ones. The interobserver agreement was excellent (kappa = 0.84).
Conclusion: EUS elastography of mediastinal lymph nodes can be performed reliably. The results are good for a noninvasive technique, but they remain inferior to the success rate of EUS-guided FNAB. The method might occasionally be useful for targeting the most suitable lymph nodes for FNAB.
References
1
Wiersema M J, Vilmann P, Giovannini M. et al .
Endosonography-guided fine-needle aspiration biopsy: diagnostic accuracy and complication assessment.
Gastroenterology.
1997;
112
1087-1095
2
Fritscher-Ravens A, Sriram P V, Bobrowski C. et al .
Mediastinal lymphadenopathy in patients with or without previous malignancy: EUS-FNA-based differential cytodiagnosis in 153 patients.
Am J Gastroenterol.
2000;
95
2278-2284
3
Fritscher-Ravens A, Sriram P V, Topalidis T. et al .
Diagnosing sarcoidosis using endosonography-guided fine-needle aspiration.
Chest.
2000;
118
928-935
4
Larsen S S, Krasnik M, Vilmann P. et al .
Endoscopic ultrasound guided biopsy of mediastinal lesions has a major impact on patient management.
Thorax.
2002;
57
98-103
7
Moon K M, Chang R F, Chen C J. et al .
Solid breast masses: classification with computer-aided analysis of continuous US images obtained with probe compression.
Radiology.
2005;
236
458-464
8
König K, Scheipers U, Pesavento A. et al .
Initial experiences with real-time elastography guided biopsies of the prostate.
J Urol.
2005;
174
115-117
10
Giovannini M, Hookey , Bories E. et al .
Endoscopic ultrasound elastography: the first step towards virtual biopsy? Preliminary results in 49 patients.
Endoscopy.
2006;
38
344-348
11
Sa±ftoiu A, Vilmann P, Hassan H. et al .
Analysis of endoscopic ultrasound elastography used for characterization and differentiation of benign and malignant lymph nodes.
Ultraschall Med.
2006;
27
535-542
13
Janssen J, Schlörer E, Greiner L.
EUS elastography of the pancreas: feasibility and pattern description of the normal pancreas, chronic pancreatitis, and focal pancreatic lesions.
Gastrointest Endosc.
2007;
65
971-978
14
Janssen J, Johanns W, Luis W. et al .
Clinical value of endoscopic ultrasound-guided transesophageal fine needle puncture of mediastinal lesions.
Dtsch Med Wochenschr.
1998;
123
1402-1409
17
Schmulewitz N, Wildi S M, Varadarajulu S. et al .
Accuracy of EUS criteria and primary tumor site for identification of mediastinal lymph node metastasis from non-small-cell lung cancer.
Gastrointest Endosc.
2004;
59
205-212
