<unk>  <unk> , also called<unk> l<unk> l<unk> , is a measurement of the<unk>  of tunica<unk>  and tunica<unk> , the innermost two layers of the wall of an artery. The measurement is usually made by external ultrasound and occasionally by internal, invasive ultrasound catheters. Measurements of the total wall<unk>  of blood vessels can also be done using other imaging modalities. Carotid<unk>  is used to detect the presence of atherosclerosis in humans and, more contentiously, to track the regression, arrest or progression of atherosclerosis. Ultrasound measurements of carotid<unk>  were first proposed and validated in vitro by Paolo Pignoli in 1984 and further details were subsequently published in a highly cited article. The use of<unk>  as a non-invasive tool to track changes in arterial walls has increased substantially since the mid-1990s. Although carotid<unk>  is predictive of future cardiovascular events, the usefulness of measuring change in carotid<unk>  over time is disputed, as meta-analyses have not found that change in carotid<unk>  is predictive of cardiovascular events. As such, the use of change in carotid<unk>  as a surrogate endpoint measure of drug efficacy in clinical trials, or in clinical management of cardiovascular disease, is debated. Carotid<unk>  is occasionally used in clinical practice, but its role is not clear. After systematically reviewing the evidence base, the United States Preventive Services Task Force found no support for its routine use in stratification of risk for people at intermediate cardiovascular risk. However, in 2003 the European Society of Hypertension–European Society of Cardiology guidelines for the management of arterial hypertension recommended the use of carotid<unk>  measurements in high-risk patients to help identify target organ damage and in 2010 the American Heart Association and the American College of Cardiology advocated the use of carotid<unk>  on intermediate risk patients if usual risk classification was not satisfactory.
Intima-media thickness
Coronary perfusion pressure
Arterial resistivity index
Vascular resistance
Flow-mediated dilation
Thrombus perviousness
Transpulmonary pressure
Instantaneous wave-free ratio