Accelerated contrast-enhanced whole-heart coronary MRI using low-dimensional-structure self-learning and thresholding

Area of Science:

• Magnetic Resonance Imaging
• Cardiovascular Imaging
• Image Reconstruction

Background:

• Accelerated MRI techniques are crucial for reducing scan times in cardiovascular imaging.
• Contrast-enhanced whole-heart coronary MRI (CE-WHC-CMR) is vital for diagnosing coronary artery disease.
• Artifacts and reduced image quality are challenges in highly accelerated MRI.

Purpose of the Study:

• To evaluate the efficacy of prospective random undersampling with phase ordering and low-dimensional-structure self-learning and thresholding (LDSST) reconstruction for highly accelerated CE-WHC-CMR.
• To compare LDSST reconstruction with standard zero-filled reconstruction for image quality and diagnostic performance.

Main Methods:

• Prospective random undersampling with phase ordering was implemented for CE-WHC-CMR acquisition.
• Acquisitions were performed in 10 healthy subjects at 4-fold acceleration and in 4 patients with suspected coronary artery disease at 3-fold acceleration.
• Undersampled images were reconstructed using LDSST and compared to zero-filled images.

Main Results:

• LDSST reconstruction showed significant improvements in depicted vessel length, vessel sharpness, and subjective image quality compared to zero-filled images (overall score: 3.6 ± 0.5).
• Reconstructed images in patients were all diagnostic.
• The technique achieved diagnostic image quality at up to 4-fold acceleration using a standard 5-channel coil.

Conclusions:

• LDSST reconstruction is effective for improving image quality in highly accelerated CE-WHC-CMR.
• This method allows for significant acceleration of CE-WHC-CMR while maintaining diagnostic image quality.
• The findings support the clinical utility of LDSST for faster and more efficient coronary MRI.