certainly individuals may become proficient in more than one area of testing.
at a minimum, individuals should become registered in each area they provide
services to patients.
the key seems to be the motivation and interest of the person performing the
diagnostic studies. some enjoy the opportunity to practice in multiple
specialities; others enjoy specializing in one particular area. i find that
problems with quality occur when facilities take a "blanket" approach to
cross training. filling staffing slots takes precedence; everyone is forced
to do everything, regardless of interest/level of training/expertise. this
approach sacrifices quality for quantity.