title: When is a number not a number? Quality control arrives in the imaging laboratory.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Marwick
mesh_terms: D002309:Cardiology / Q000193:education* / Q000592:standards*; D019411:Clinical Laboratory Techniques / Q000592:standards*; D004452:Echocardiography / Q000592:standards*; D006801:Humans; D013318:Stroke Volume; D013663:Teaching / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*; D016277:Ventricular Function, Left