Differentiation of metastatic cervical lymph nodes with ultrasound elastography by virtual touch tissue imaging: preliminary study.

ABSTRACT

OBJECTIVES: The purpose of this study was to investigate the clinical usefulness of acoustic radiation force impulse elastography for the differential diagnosis of cervical lymph nodes. METHODS: Virtual touch tissue imaging (Siemens Medical Solutions, Mountain View, CA) was analyzed in 81 patients (mean age, 46.6 years; range, 5-82 years) with 81 lymph nodes (45 metastatic nodes and 36 benign nodes). RESULTS: Most benign lymph nodes were slightly darker or the same in brightness compared with surrounding tissue, whereas most metastatic nodes were obviously darker. The mean area ratio of benign lymph nodes ± SD (1.05 ± 0.15) was statistically lower than the mean area ratio of metastatic lymph nodes (1.39 ± 0.20; P < 0.001). The area ration cutoff level for metastatic lymph nodes was estimated to be 1.16. With the use of a receiver operating characteristic curve with this cutoff value, the area ratio predicted malignancy with sensitivity of 91.1%, specificity of 83.3%, and an area under the curve of 0.925. CONCLUSIONS: Acoustic radiation force impulse imaging is feasible for cervical lymph nodes. The Virtual Touch tissue imaging technique can complement conventional sonography, thereby making it easier to diagnose cervical lymph nodes.