Is a radiologist technically a doctor?

Yes.: A Radiologist is a medical doctor; before one can call him/herself a radiologist, he/she has to graduate from a medical school and successfully complete a radiology residency program.

Yes: Radiologists are very much doctors (either MD or DO), with at least 9 years of training after college. However, it is often confusing because radiology technologists (the ones who take the xray or operate the CT/MRI machine) are often mistaken for a radiologist. Radiology Technologists are not physicians, but rather medical assistants who have studied for 2 or 4 years after high school.

Radiologists: Sure. They finish medical school then complete a Radiology Residency program before they can specialize in Radiology.