That's an interesting and plausible theory... however, there are over twenty apps that do this already—ranging in price from free to over $400, some from top name companies—and radiologists are already doing it without FDA approval. . . just as they were doing it on Macs years ago prior to FDA bureaucratic approval.
The radiologists are perfectly capable of making a judgement as to whether the images are sufficiently clear or not to make the diagnosis. They read images far more often than do the desk bound bureaucrats who will determine whether to approve or disapprove the devices based on testimony from entrenched industry lobbyists and lunches and expense paid trips footed by eager new device/software developer lobbyists. It is, after all, the radiologists, who place their practices, reputations, and assets on the line when they make their diagnoses, risking mal-practice lawsuits if they misdiagnose the case, not the bureaucrat.