Ensuring respiratory phase consistency to improve cardiac function quantification in real-time CMR.

Area of Science:

• Cardiovascular imaging
• Medical physics
• Biomedical engineering

Background:

• Real-time (RT) cardiac MRI is crucial for assessing cardiac function.
• Respiratory motion can introduce inaccuracies in cardiac function quantification.
• Accurate synchronization with respiratory phases is needed for reliable RT cardiac MRI analysis.

Purpose of the Study:

• To develop an automated method for selecting heartbeats with consistent respiratory phases in RT cardiac MRI.
• To enhance the accuracy of cardiac function quantification using this automated selection.
• To improve the robustness and reliability of RT cardiac MRI analysis.

Main Methods:

• Respiratory signal extraction from RT cine images using principal component analysis.
• A two-step procedure to determine the directionality of the respiratory signal.
• Validation using multislice RT cine data from volunteers and patients, comparing with a manually selected region-of-interest.

Main Results:

• The proposed method demonstrated a high, positive correlation with the reference respiratory signal.
• The method proved more robust than a recently proposed alternative.
• Selecting heartbeats at the expiratory phase improved agreement for right ventricular function quantification.

Conclusions:

• The developed method automates respiratory signal extraction and directionality determination in RT cardiac cine images.
• This automation leads to more accurate cardiac function quantification.
• The findings support the clinical utility of this method for improved RT cardiac MRI analysis.