MRCT, MRI, or a CT Chest?

Unenhanced CT can be an okay way to detect some of these, and then you said that the CT with all these fancy washout studies is not as helpful as we used to think it was. And then there's MRI and MRI tests, because sometimes I feel like this happens sometimes where we'll have a CAT scan, and then the radiologist asks for another CAT scan. Is there any preferred tests that we should get as follow-up to the initial?