Cardiovascular ImagingIndicator dilution method
method for measuring
cardiac output or regional blood flow based upon analysis of an arterial indicator clearance curve. It is frequently called the Stewart Hamilton technique in recognition of the investigators who promulgated the technique. Indocyanine dye has been used extensively to measure
cardiac output. In recent years cold saline has been more frequently used as the indicator (
thermodilution method). The arterial timeconcentration curve produced after
intravenous or right heart injection of an indicator demonstrates a recirculation hump on the downslope of the curve with left to right shunts or early appearance and hump on the upslope of the curve with right to left shunts. For angiographic applications, the indicator is iodinated contrast medium and a time density curve is recorded in an arterial region of interest. This contrast washout analysis has been used with
electron beam CT and digital
angiography to estimate blood flow or
perfusion in the coronary and other regional circulations.
CBH