The classical physicians of the pre-19th century could talk with there patient and classify symptoms , described and sometimes named there physical signs, but could do little about them (So easy to organise a FRACP clinical exam!)

The ability to look inside the body initially came with sound in the form of the stethoscope.  Since then investigations have been able to map out the human pathology with increasing precision, but come with costs of time, money and distance from the ordering physician. Some clinicians have come to rely on imaging and investigative modalities to make diagnoses, rather than altering a pre-test probablity.

Ultrasound could also fall into this trap. But in the hands of a physician who takes a history, looks for signs, listens with there stepthoscope, consults a CXR and ECG, contempates diagnoses and asks specific questions of ultrasound. They and there patients are further down the diagnosic road before more resoruce intense investigations are ordered.