Clinical application of pulsatility index

Abstract

Pulsatility index (PI) is defined as the difference between the peak systolic flow and minimum diastolic flow velocity, divided by the mean velocity recorded throughout the cardiac cycle. It is a non-invasive method of assessing vascular resistance with the use of Doppler ultrasonography. It was first introduced in 1974 by Gosling and King and is also known as the Gosling Index. PI as a method of examining macrocirculation has a variety of clinical applications. For instance, in diabetic patients, it has been measured on the common carotid, middle cerebral or renal arteries to help predict complications such as cerebrovascular disease or nephropathy. In hypertensive patients, it has been used to assess complications and assess the chronicity of the disease. To our knowledge, despite the diverse use of this ultrasonographic parameter, there is a deficiency in reports that would comprehensively summarize its clinical applications. Based on our extensive review of the literature and the gathered information, we conclude that pulsatility index (PI) is an easy to obtain parameter with a broad range of both, research and clinical applications. It has been widely used in the assessment of macrocirculation in highly prevalent chronic medical conditions, such as hypertension, both type 1 and type 2 diabetes and thyroid disorders.