Angio means Blood
Angio = blood, gram = picture; thus angiograms are pictures which show a 2d image, still or motion, of dye added into the blood, so that the dye/blood column shows on x-ray.
Without the dye, the blood looks same on x-ray as surrounding tissues. Procedures commonly done by cardiologists (such as i), radiologists or, sometimes, vascular surgeons
. Also by ophthalmologists for the vessels of the eye