Increased accuracy of head and neck sonography using harmonic imaging.

The aim of new techniques in head and neck sonography is to increase the se nsitivity and the specificity of the examination. With tissue harmonic imag ing (THI) and contrast harmonic imaging (CHI) new techniques are available which allow increased contrast and resolution in head and neck sonography a s well as a better detection of small blood vessels. Methods: We studied wh ether these techniques improve sonographic detection of head and neck lymph nodes and primary tumours of the upper aerodigestive tract. Results: The r esults indicate that THI allows a better detection of cervical lymph nodes. Furthermore, intranodal structures and the borders of the lymph node can b e better detected. Using CHI, typical patterns of vascularization can be se en, allowing a better interpretation of the node's tumour status. Primary t umours can be detected sufficiently well using conventional B-scan techniqu es although they are easier to detect with THI. Using CHI, many tumour vess els can be detected, but this does not increase the sensitivity of the sono graphic examination. Conclusion: THI and CHI may increase the specificity o f sonographic diagnostics of cervical lymph nodes but show no clinical bene fit regarding the diagnostics of primary tumours of the upper aerodigestive tract.