Believe me because I know better ... that's not really convincing.This is simply not true. I am sorry that you don't believe we scientists understand how to do science but I don't know how else to explain it to you briefly enough to fit in a comment.
Enjoy being smarter than researchers everywhere!
How may people without health problems have CT scans? There are surely hypochondriacs and some diagnostic overuse, but the majority have problems serious enough to warrant a scan.
Of course scientists generally know how to do science, but this is just one study making dubious claims - not some collective endeavor of 'researchers everywhere'.