Noninvasive atherosclerosis assessment for controlled clinical trials.
Non-invasive imaging used in controlled clinical trials should be able to detect an average 1.5 to 3 percent change in atherosclerosis growth rate per year. This can now be achieved by selective arterial angiography, an invasive procedure. IV digital subtraction angiography and B-mode ultrasound imaging are the two most promising non-invasive procedures for early application in clinical trials. In carotid artery, the resolution of fine details of lesions by IV angiography is approximately one-half that of selective angiography. The resolving power of ultrasound images depends greatly on frequency of the ultrasound beam and is greatest along the axis of the beam which is perpendicular to the vessel. Nuclear magnetic resonance imaging and computerized axial tomography with enhanced tissue contrast show potentially useful images of coronary artery bypass grafts. Whatever imaging procedure is selected, a major emphasis in trial design should be to produce a large difference in atherosclerosis change rate between test and control groups. A potential advantage of small-scale clinical trials that measure atherosclerosis change is that large reductions in plasma lipid level are possible.
D000328:Adult; D000368:Aged; D000792:Angiography / Q000379:methods; D000818:Animals; D001161:Arteriosclerosis / Q000175:diagnosis*; D002986:Clinical Trials as Topic; D003327:Coronary Disease / Q000175:diagnosis; D004285:Dogs; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008875:Middle Aged; D014463:Ultrasonography / Q000379:methods