I forgot to mention the ultrasound is used frequently for (fine) Needle Guided Biopsy as well.

It is not listed in the NCCN Oncology Practice Guidelines for either original workup or followup exams for H&N patients.

It would not be an "off label" use for the device though since most US systems are indicated for "small parts". Ideal frequencies for the probes used in the head & neck area would be in the 7Mhz to 24MHz range depending on the depth of the region of interest, the higher frequencies being used for areas close to the skin.

I would add to what Ginny had to say in that there is also a wide variation in the quality of the machines out there as well, everything from inexpensive black & white mechanical sector to phased, linear and curved array, multiple channel, tissue harmonic imaging, 3D/4D (4D meaning 3D with motion), color machines, such as the GE Voluson 730.

There is also a shortage of trained sonographers in the US today. It is a good profession but handling the probes all day, with the pressure required for good coupling, takes it's toll on the operators and technicians. Many suffer from carpal tunnel syndrome and their careers are cut short.