I am currently studying to be a radiologist. The technology used to view and treat diseases within the human are amazing! 
Interesting, what does a radiologist do exactly ?
They prepare and use imagining technology like X-rays, CT scans and ultrasound machines to help diagnose patients. If you've ever broken a bone, you've probably met one.
OK, and when radiology was invented ?
The first uses of such technology go back to the early 1900s, but possibly even before. The exact time isn't super clear. 
I did not expected to be so old, it seems that CT scanners were introduced in hospitals in the last 40 years, am I right ?
Sort of. The first commercially available CT scanner was developed in the 1960s, but the machines were around since the 1910s.