Intima-media thickness (IMT), also called intimal medial thickness, is a measurement of the thickness of artery walls, usually by external ultrasound, occasionally by internal, invasive ultrasound catheters, see IVUS, to both detect the presence and to track the progression of atherosclerotic disease in humans. IMT has increasingly been used in medical research since the mid-1990s to track changes in arterial walls. However, its usefulness as a research tool is disputed, as regression of IMT has been found to be poorly predictive of reduction of cardiovascular events...