Myocardial perfusion imaging using contrast echocardiography

A program for objective automatic mapping of myocardial perfusion was developed. The program acquires a sequence of end-diastolic ultrasound images, using automatic echocardiography gating. Each image is divided into multiple regions of interest. The division is done either manually tracing the endocardial and epicardial borders, or automatically, using a running square window which covers the entire image. The analysis is based on changes in the local video intensity levels (range: 0. . .255). In each segment the background (pre-injection) level is subtracted throughout the sequence of images, and the relative local perfusion is estimated from the washout curve by calculating parameters such as peak intensity, area under washout curve, and time to peak. From these values a new color coded image, in which hot colors represent normal regions, and cold colors represent ischemic regions, is generated. Regional function of the same slice is calculated by a wall thickening algorithm, measuring the relative change in wall thickness from end-diastole to end-systole