Bootstrap quantification of cardiac pulsation artifact in DTI

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Diffusion Tensor Imaging (DTI)

Background:

• Cardiac gating benefits diffusion MRI (dMRI) with single-shot EPI, but is underutilized due to perceived time costs.
• Investigators question the added value of cardiac gating versus the extra effort required.

Purpose of the Study:

• To evaluate a clinically feasible cardiac gating protocol with minimal scan time increase.
• To quantify the impact of cardiac gating on DTI parameters under partial and full Fourier acquisition.

Main Methods:

• Eight volunteers underwent 3T MRI with a SENSE 8-channel head coil.
• Diffusion-weighted, single-shot spin-echo EPI images were acquired with/without cardiac gating and partial/full Fourier.
• Vectorcardiography (VCG) triggered acquisition with a minimum 30 ms delay; DTI parameter uncertainties were estimated via bootstrap.

Main Results:

• Cardiac gating reduced uncertainties and improved DTI parameter variability efficiency with partial Fourier acquisition.
• Full Fourier acquisition with minimum delay gating showed minimal uncertainty reduction and worse efficiency.
• Minimum trigger delay allows clinically acceptable scan times, though may not optimally avoid systole.

Conclusions:

• Cardiac gating, particularly with partial Fourier acquisition, effectively reduces DTI parameter uncertainties.
• This approach offers a time-efficient method to improve DTI data reliability in clinical settings.