Nontriggered MRI quantification of aortic pulse-wave velocity

Area of Science:

• Cardiovascular Imaging
• Biomedical Engineering
• Medical Physics

Background:

• Arterial stiffness, indicated by pulse-wave velocity (PWV), is a key predictor of cardiovascular risk.
• Accurate and efficient measurement of PWV is crucial for clinical risk stratification.

Purpose of the Study:

• To introduce a novel, high-speed magnetic resonance imaging (MRI) technique for time-resolved quantification of pulse-wave velocity.
• To simplify PWV measurement by utilizing complex difference signals from velocity-encoded projections.

Main Methods:

• Developed a non-gated, high-speed MRI technique to acquire time-resolved complex difference signal intensity in the aorta.
• Estimated pulse wave propagation time from the velocity-time curve derived from signal intensity.
• Measured pulse wave path length from oblique sagittal images.
• Calculated PWV as the ratio of path length to propagation time.

Main Results:

• The technique successfully quantified PWV in healthy subjects (N=23, ages 20-70) at 1.5 T and 3 T.
• Results showed good agreement with established literature, demonstrating an age-related increase in aortic stiffness.
• Root-mean-square differences between the proposed method and retrospectively EKG-gated PC-MRI were less than 4%.

Conclusions:

• The proposed high-speed MRI method offers a simplified approach for PWV quantification.
• This technique requires only complex difference signal computation, reducing data acquisition and processing complexity.
• It provides a promising tool for assessing arterial stiffness and cardiovascular risk.