A computerized method of quantitative analysis of ventricular phase distributions

Area of Science:

• Cardiology
• Medical Imaging
• Quantitative Analysis

Background:

• Gated equilibrium cardiac studies provide insights into cardiac function.
• Acute myocardial infarction (AMI) significantly impacts myocardial contraction synchronism.
• Quantitative analysis of phase images can offer objective measures of cardiac performance.

Purpose of the Study:

• To quantitatively analyze phase images from gated equilibrium cardiac studies in normal subjects and AMI patients.
• To evaluate the relationship between intra- and interventricular phase shifts, and the percentage of normal contracting pixels (NCP) with left ventricular ejection fraction (LVEF).
• To determine the utility of these parameters in the prognosis and follow-up of AMI patients.

Main Methods:

• Quantitative analysis of phase images from gated equilibrium cardiac studies using a computerized automatic method.
• Construction of phase histograms for each ventricle, with peak identification via convolution algorithm.
• Calculation of intra- and interventricular phase shifts and percentage of normal contracting pixels (NCP).

Main Results:

• Left ventricular ejection fraction (LVEF) tends to decrease with increasing intraventricular phase shift.
• Interventricular phase shifts outside the normal range (+/- 10 degrees) were primarily observed in patients with extensive anterior or anteroseptal AMI.
• The strongest correlation was found between LVEF and the percentage of NCP, which decreases as akinetic and dyskinetic areas increase.

Conclusions:

• The percentage of normal contracting pixels (NCP) serves as a quantitative index of myocardial contraction synchronism.
• NCP is a valuable parameter for the prognosis and follow-up of patients with acute myocardial infarction.
• Quantitative phase analysis of cardiac imaging can provide objective insights into cardiac function post-MI.