Highly accelerated MRI by skipped phase encoding and edge deghosting with array coil enhancement (SPEED-ACE)

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Medical Imaging Technology
• Image Reconstruction

Background:

• Fast MRI methods are crucial for reducing scan times and improving patient comfort.
• Existing parallel imaging techniques like SENSE face limitations in undersampling factors.
• Ghosting artifacts can degrade image quality in accelerated MRI.

Purpose of the Study:

• To develop and evaluate SPEED-ACE, an enhanced fast MRI method.
• To improve undersampling capabilities beyond the number of receiver coils.
• To achieve high-quality deghosted images with significant k-space acceleration.

Main Methods:

• Developed SPEED-ACE by combining skipped phase encoding with array coil enhancement.
• Utilized differential filtering to create ghosted edge maps from sparsely sampled k-space data.
• Employed least-square-error minimization with data from at least three coils for deghosting.
• Applied inverse filtering to reconstruct the final deghosted image.

Main Results:

• SPEED-ACE achieved an undersampling factor of N using N skipped phase encoding steps and parallel coils.
• Demonstrated effective reduction of overlapping aliasing ghosts through edge enhancement.
• Successfully reconstructed deghosted images from sparsely sampled k-space data.
• Showcased potential for undersampling factors greater than the number of receiver coils in vivo.

Conclusions:

• SPEED-ACE is a novel parallel imaging method offering significant acceleration in MRI.
• The technique effectively mitigates ghosting artifacts, enhancing image quality.
• SPEED-ACE surpasses current parallel imaging methods in achieving high undersampling factors.