How do you tell what plaque type you have without an angiogram?

Need more info. I am not sure about your question. Plaques are usually formed by abnormal accumulation of different versions of cholesterol that are affected by many factors like diabetes, hypertension, smoking, genetics, meds, etc. They cause trouble more based on location and age of the plaque (older can be more stable), as well as these other factors, than by a certain type.
OnlyGuessCannotTell. Angio = blood, gram = picture; 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. Artery ds: an accumulation of white blood cells, living & dead, within artery walls. Arteries enlarge/not narrow in response to ds. Wall not shown in angiogram images+only larger openings visible. Stenosis due to plaque rupture & clots in opening.