Method for measuring myocardium ultrasonic angiography image physiological parameters based on empirical mode decomposition (EMD)

Abstract

The invention relates a method for analyzing a time-intensity curve of a myocardium ultrasonic angiography image, in particular to a method for measuring myocardium ultrasonic angiography image physiological parameters based on EMD. The method includes dividing a myocardial area into six areas according to a circumference, extracting perfusion signals and extracting a time-intensity curve of each of divided myocardial areas respectively; performing EMD on an extracted time-average gray value intensity curve to obtain an expanded signal intrinsic mode function, performing Hilbert transform on the obtained first intrinsic mode function to obtain instantaneous spectrum parameters, and adding amplitude values of each frequency point to obtain a marginal spectrum; and performing threshold judgment on a marginal spectrum through energy thresholds of the marginal spectrum. According to the method, an analytical approach based on the myocardium ultrasonic angiography image is provided for diagnosing myocardial infarction or myocardial microcirculation, and further physiological parameter measurement accuracy based on the myocardium ultrasonic angiography image is improved, and doctor subjective dependence is reduced.

Description

technical field [0001] The invention relates to a method for analyzing time-intensity curves of myocardial ultrasound contrast images, in particular to a method for feature extraction of time-intensity curves by using empirical mode decomposition and a method for measuring physiological parameters by using Hilbert marginal spectrum. Background technique [0002] The heart is an important organ of the human body. With each contraction of the heart, the blood carrying oxygen and nutrients is transported to the whole body through the aorta to supply the metabolic needs of various tissue cells. Due to abnormal lipid metabolism, lipids in the blood deposit on the smooth coronary intima, forming thrombus. Once microthrombosis forms, it will cause severe stenosis or even blockage of microvessels, resulting in abnormal microcirculation perfusion. In severe cases, acute myocardial ischemia, necrosis, or even life-threatening. Even if coronary revascularization is used for treatment,...

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Problems solved by technology

[0009] Clinically, fitting curves are often used to qualitatively measure the myocardial parameters of contrast medium perfusion, but such measurement methods are very dependent on the experience of doctors, and there are certain measurement errors; at the same time, since the fitting curve only reflects the time-average grayscale The change trend information of the curve, but more information contained in the curve cannot be expressed by fitting the curve, so usually the fitting curves of the healthy myocardial area and the myocardial infarction area are basically similar, and the measured physiological parameters cannot be expressed The nature of the area to be diagnosed, so the clinical practical value of physiological parameter measurement using the fitted curve is limited

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