Cardiac MR elastography using reduced-FOV, single-shot, spin-echo EPI.

Area of Science:

• Medical Imaging
• Biophysics
• Cardiovascular Imaging

Background:

• Cardiac magnetic resonance elastography (MRE) is an emerging technique for non-invasively assessing myocardial stiffness.
• Conventional MRE techniques often suffer from artifacts such as ghosting, which can degrade image quality and hinder accurate stiffness quantification.
• Optimizing acquisition strategies is crucial for improving the diagnostic utility of cardiac MRE.

Purpose of the Study:

• To implement and evaluate a reduced field of view (rFOV) technique for cardiac MRE.
• To compare the image quality of rFOV cardiac MRE with the conventional full field of view (full-FOV) acquisition.
• To assess the impact of rFOV on both magnitude images and post-processed MRE stiffness maps.

Main Methods:

• Seventeen healthy volunteers underwent both full-FOV and rFOV cardiac MRE scans at 140 Hz.
• Two radiologists performed blinded comparative assessments of magnitude images and stiffness maps.
• Quantitative analysis included octahedral shear strain-based signal-to-noise ratio (OSS-SNR) and myocardial stiffness measurements.

Main Results:

• rFOV cardiac MRE demonstrated superior subjective image quality and reduced ghosting artifacts compared to full-FOV MRE.
• Quantitative analysis revealed a significantly higher OSS-SNR in rFOV scans (2.1 vs. 1.4).
• A reduction in stiffness variation within the myocardium was observed with rFOV in a subgroup of subjects.

Conclusions:

• The rFOV technique for cardiac MRE effectively reduces ghosting artifacts.
• This method significantly improves image quality in both MRE magnitude images and stiffness maps.
• rFOV cardiac MRE shows promise for enhanced diagnostic accuracy in cardiovascular assessments.