When I was doing medical transcription, the radiology transcriptionists were a whole separate pool from us "general" MTs. There had to be a at least a couple of them available 24/7 b/c any kind of imaging report was automatically a STAT with a turnaround time of an hour or less (back then, the turnaround time for standard transcription could be a week).
After voice recognition software, the whole transcription world changed and EVERYTHING was getting turned around much, much faster. Imaging reports were being turned around almost instantly, plus imaging was now digital. This meant the doc could pull up on his monitor both the image and the report of the read by the radiology guy just about as soon as the rad guy dictated his read.
And that all amounts to Lexie going for her scan and having the doc say "I'll call you later today and let you know what we've got here", something that couldn't have happened in the not-so-distant past.