Three-dimensional motion corrected free-breathing simultaneous multislice-balanced steady state free...

Area of Science:

• Cardiovascular Imaging
• Magnetic Resonance Imaging
• Medical Physics

Background:

• Developing advanced imaging techniques for free-breathing myocardial perfusion is crucial for accurate diagnosis.
• Simultaneous multislice (SMS) balanced steady-state free precession (bSSFP) offers potential for high spatial resolution and coverage.
• Motion artifacts remain a challenge in cardiac MRI, particularly during free-breathing acquisitions.

Purpose of the Study:

• To develop and evaluate a novel 3D motion-corrected SMS-bSSFP acquisition for free-breathing myocardial perfusion.
• To assess the efficacy of a fast diaphragmatic respiratory navigator (fastNAV) in conjunction with SMS-bSSFP for prospective slice-tracking.
• To compare the new 3D motion correction strategy against standard in-plane correction methods.

Main Methods:

• Implementation of a fast diaphragmatic respiratory navigator (fastNAV) (<15ms) into an SMS-bSSFP sequence for prospective slice-tracking.
• Correction of residual 2D in-plane motion using inline image registration.
• Comparison of the developed SMS-fastNAV approach with a reference SMS perfusion protocol (SMS-Ref) in 10 patients at 1.5T, assessing left ventricular (LV) motion using DICE coefficient (avDICE) and center of mass displacement (avCOM).

Main Results:

• SMS-fastNAV demonstrated significantly lower residual LV motion compared to SMS-Ref before non-rigid registration, indicated by higher avDICE (0.93±0.02 vs. 0.89±0.04) and decreased avCOM (2.82±0.89mm vs. 4.23±1.29mm).
• Following non-rigid registration, SMS-fastNAV maintained higher avDICE (0.95±0.01 vs. 0.94±0.02) and showed a trend towards reduced avCOM (0.97±0.21mm vs. 1.01±0.25mm), suggesting improved through-plane motion correction.
• No statistically significant differences in subjective image quality were observed between the SMS-fastNAV and SMS-Ref methods (1.79±0.50 vs. 2.00±0.59).

Conclusions:

• A 3D motion correction strategy was successfully developed for free-breathing SMS-bSSFP perfusion.
• The developed strategy provides improved motion correction compared to standard in-plane image registration alone.
• This technique enables high spatial coverage and resolution for free-breathing myocardial perfusion MRI.