I believe in the case of breast cancer screening that AI is useful because there can be some degree of subjectivity in the interpreration, and an AI can be trained to spot certain patterns. I don't know much about PCR interpretation but in my field, biochemistry, I'm not sure it would be too useful for individual results. Maybe in spotting overall clinical patterns, but we do have algorithms in place for some things like that. But even all our automated processes are checked and authorised by a BMS or Clinical Scientist before release.
Anyway, even if it were for some reason desirable, just the time it would take to procure, train, test, troubleshoot and validate a system would be prohibitive. As you can imagine we have a very rigorous quality management system it would need to get through and I don't think it could be done.