[...] When using ultrasound for regional anaesthesia it is essential to have a good understanding of basic ultrasound physics in order to obtain the best possible image.   Part 2 of The Physics of Ultrasound will examine ultrasound phenomena, such as anisotropy and artefact, to understand how these can affect image quality and what practical steps can be taken to reduce their effects. The article will also look at the Doppler effect before finishing with a few practical hints and tips on how to ensure the best images are obtained. (For part 1 click here) [...]