Three-dimensional High-Resolution Dark-Blood Late Gadolinium Enhancement Imaging for Improved Atrial Scar Evaluation

Area of Science:

• Cardiovascular Imaging
• Medical Physics
• Radiology

Background:

• Radiofrequency ablation (RFA) is a key treatment for atrial fibrillation, aiming to reduce cardiac arrhythmia.
• Accurate assessment of atrial scarring is crucial for guiding RFA and predicting patient prognosis.
• Conventional bright-blood late gadolinium enhancement (LGE) MRI has limitations in visualizing atrial scars due to poor contrast.

Purpose of the Study:

• To develop and evaluate a free-breathing LGE cardiac MRI technique.
• The technique aims to simultaneously acquire high-spatial-resolution dark-blood and bright-blood images.
• The goal is to improve atrial scar detection and quantification.

Main Methods:

• A novel free-breathing, navigator-gated, dark-blood phase-sensitive inversion recovery (PSIR) sequence was developed.
• Two coregistered 3D volumes (dark-blood and bright-blood) were acquired with high spatial resolution (1.25 × 1.25 × 3 mm³).
• The sequence was tested in 20 patients post-RFA for atrial fibrillation, comparing image contrast and scar quantification against conventional PSIR and electroanatomic mapping (EAM).

Main Results:

• The new PSIR sequence successfully acquired high-resolution 3D images in all participants within a mean scan time of 8.3 minutes.
• Significantly improved scar-to-blood contrast was observed compared to conventional PSIR (0.60 au vs. 0.20 au, P < .01).
• Scar area quantification using the new sequence showed a strong correlation with EAM (r = 0.66, P < .01), unlike conventional PSIR (r = 0.13, P = .63).

Conclusions:

• The developed dark-blood PSIR sequence provides high-resolution dark-blood and bright-blood images.
• This technique offers superior image contrast for visualizing atrial scars post-RFA.
• It enables more accurate scar quantification compared to conventional bright-blood LGE MRI.