Processing and Analysis of Cardiac Signals for MRI Triggering.

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Cardiovascular Diagnostics

Background:

• Magnetic Resonance Imaging (MRI) provides detailed insights into tissue and function.
• High-field MRI (up to 7 T) presents motion compensation challenges, necessitating precise cardiac signal acquisition for timed-triggered imaging.
• Accurate triggering is vital for high-quality diagnostic MRI, especially in cardiovascular applications.

Purpose of the Study:

• To evaluate and compare the accuracy of three cardiac signal acquisition methods for MRI triggering: electrocardiography (ECG), photoplethysmography (PPG), and ballistocardiography (BCG).
• To determine the most reliable method for precise cardiac synchronization in high-field MRI environments.
• To assess the impact of magnetic interference on the performance of these triggering techniques.

Main Methods:

• Data acquisition from 32 healthy volunteers undergoing MRI.
• Comparative analysis of ECG (R-wave detection), PPG (pulse wave detection), and BCG (J-wave detection) for cardiac signal timing.
• Performance evaluation using F1 scores to quantify detection accuracy.

Main Results:

• Photoplethysmography (PPG) demonstrated the highest accuracy with an F1 score of 99.21% for pulse wave detection.
• Ballistocardiography (BCG) showed strong performance with an F1 score of 91.15% for J-wave detection.
• Electrocardiography (ECG) exhibited lower accuracy (F1 score 70.97%) due to significant magnetic interference in the MRI environment.

Conclusions:

• Photoplethysmography (PPG) is the most reliable and accurate method for MRI triggering in high-field settings.
• Ballistocardiography (BCG) serves as a viable alternative for MRI triggering.
• Electrocardiography (ECG) is limited in high-field MRI environments due to susceptibility to magnetic interference, impacting its diagnostic utility.