High spatial resolution EPI using an odd number of interleaves.

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Image Reconstruction
• Artifact Reduction

Background:

• Ghost artifacts in echoplanar imaging (EPI) stem from phase errors during kx traversal.
• Conventional reference scans for artifact reduction are often ineffective and can degrade image quality.
• Existing ghost artifact reduction techniques are limited to single-shot EPI due to ghost overlap constraints.

Purpose of the Study:

• To develop a ghost artifact reduction method applicable beyond single-shot EPI.
• To investigate the impact of interleaf number on ghost artifact formation and correction.
• To introduce a novel EPI acquisition strategy for improved image quality.

Main Methods:

• Developed a ghost artifact reduction technique based on direct image phase correction.
• Analyzed EPI data reconstructed from even- and odd-number k-space interleaves.
• Applied phase correction to odd-number interleaf EPI data to estimate and reduce phase errors.

Main Results:

• Data from even-number interleaves produce multiple ghosts, precluding phase correction.
• Data from odd-number interleaves yield a single ghost, enabling effective phase correction.
• Image phase correction significantly reduced ghost intensity in odd-number interleaf EPI.

Conclusions:

• Odd-number interleaf EPI allows for ghost artifact reduction via image phase correction.
• This technique offers a viable alternative or complement to even-number interleaf EPI, especially when reference scans are unreliable.
• Odd-number interleaf EPI provides flexible spatial and temporal resolution tradeoffs for various MRI applications.