Modelling the integration of myocardial regional perfusion and function

Area of Science:

• Nuclear Cardiology
• Cardiovascular Imaging
• Myocardial Perfusion Imaging

Background:

• Myocardial perfusion imaging (MPI) is crucial for diagnosing coronary artery disease.
• Assessing myocardial kinetics, such as wall motion and thickening, can further refine perfusion defect characterization.
• Current methods may benefit from enhanced analytical techniques for improved diagnostic accuracy.

Purpose of the Study:

• To describe a novel method for investigating myocardial kinetics (wall motion and thickening).
• To utilize these kinetic assessments to further define myocardial perfusion characteristics.
• To evaluate the diagnostic value of kinetic abnormalities in relation to perfusion defects.

Main Methods:

• Utilized gated myocardial perfusion single-photon emission computed tomographic (SPECT) images.
• Employed a 99Tcm-labelled perfusion agent.
• Defined wall motion by the phase and amplitude of the first moment of myocardial count rate density.
• Defined wall thickening by phase and amplitude of changes in the second moment of density distribution.

Main Results:

• Wall motion abnormalities were observed in 28% of transient and 43% of fixed perfusion defects.
• Phase delays in wall motion were present in 28% (transient) and 57% (fixed) defects.
• Wall thickening abnormalities were found in 14% of transient and 86% of fixed perfusion abnormalities.
• A high positive predictive value (86%) of wall-thickening abnormalities was noted for fixed perfusion abnormalities.

Conclusions:

• The described method for assessing myocardial kinetics provides valuable information for interpreting perfusion defects.
• Wall-thickening abnormalities show a high positive predictive value for fixed perfusion defects, indicating potential myocardial viability.
• Further investigation is needed to determine if fixed perfusion defects with normal wall thickening represent viable myocardium.