Cardiac functional assessment without electrocardiogram using physiological self-navigation.

Area of Science:

• Cardiovascular Imaging
• Medical Physics

Background:

• Electrocardiogram (ECG)-gated cine MRI is crucial for cardiac function assessment.
• ECG signal acquisition can be challenging due to patient electrophysiology or high magnetic fields in MRI.

Purpose of the Study:

• To present a novel framework for cardiac functional assessment using physiological information derived directly from MRI data.
• To overcome limitations of external ECG gating in cardiac MRI.

Main Methods:

• Utilized a 2D Golden Radial acquisition scheme for multiple long-axis left ventricle slices.
• Employed functional information from the left ventricle for retrospective cine image reconstruction without ECG.
• Synchronized 2D cine slices using mitral valve closure timing.

Main Results:

• Developed physiological gating signals that strongly correlate with ECG reference signals.
• Achieved functional parameters with less than 1.3% relative difference compared to ECG-gated methods.
• Demonstrated feasibility in 15 volunteers and 4 patients.

Conclusions:

• Successfully demonstrated the capability of assessing cardiac function using only MR image-derived physiological information.
• This method offers a viable alternative to ECG-gated MRI, especially when ECG signals are unreliable.