I believe that China is using CT as the definitive test from something I read yesterday, but I can’t tell you what it was.
They started using it in the middle of last month (hence the HUGE increase in cases around Feb 15.)
The have since gotten their testing protocols up to speed and they rescinded the process.
It is an indicator, but it is not definitive.
I think it was when they were out of test kits. CT is a lousy screening test it is expensive not specific and exposes the tested individual to radiation . If test kits unavailable i would go with the clinical diagnosis. That is what we did with the first wave of west nile meningitis through a naive population . If your symptoms fit you were presumed to have it