The issue is standards, not techniques.
Hachinski
V
V
D000792:Angiography / Q000592:standards*; D016893:Carotid Stenosis / Q000175:diagnosis*; D016894:Endarterectomy, Carotid; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D014463:Ultrasonography / Q000592:standards*