Ah I wondered where you were going with the ultrasound thing... and you're correct in one use, but many surgerys do have ultrasound equipment. The Ultrasonographer interprets the ultrasound recording (something like a video) and sends their report to the requesting physician.
cardiology, electrocardiograph interpretation (is an ECG), cardiac ultrasonography (echocardiography) are all very different sciences... Ive seen a few printouts of ECG's that will have 10 different interpretations after being assessed by 10 different practioners. Thats the beauty of diagnostic programming. There are a few key giveaways that make gross diagnosis very easy though.
I will cut this entry short before I become pedantic with the terminology and the spelling....