Ultrasound fundamentals and their clinical implications for interventional cytopathologists.

OBJECTIVE: To describe the most important concepts in ultrasound physics that interventional cytopathologists need to understand in order to successfully perform ultrasound-guided needle biopsies.

METHODS: Review of the literature.

RESULTS: A deep understanding of ultrasound physics and the mathematics supporting it are not necessary. The most important concepts are frequency, attenuation, overall gain, time-gain compensation, focus, spatial resolution, temporal resolution and Doppler.

CONCLUSION: By understanding these eight basic concepts of ultrasound physics and their clinical implications, interventional cytopathologists can faithfully reproduce the imaging findings of the radiologist and locate the target to precisely guide a needle for biopsy.