US Residency Programmes
The exact period of training needed to gained ELS competency is unclear. In the US, a study to assess general EM US competency looked at 149 residency programmes. The consensus was that, in general terms, 150 scans were required.
This was not based on any evidence, however, and in fact only 65 residency programmes responded. The implication is that the majority of programmes were a little more flexible.
In fact using simple scan numbers is considered to be educational flawed. The GMC has commented on this regarding surgical skills, and has taken the view that competency is the goal, not the number of practical procedures conducted.