Segmented K-space blipped-controlled aliasing in parallel imaging for high spatiotemporal resolution EPI.

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Image Acquisition Techniques

Background:

• Traditional controlled aliasing in parallel imaging (CAIPI) methods offer limited EPI trajectory choices.
• Existing approaches restrict EPI factor and phase encode bandwidth selection based on the CAIPI pattern.

Purpose of the Study:

• To propose a novel segmented k-space skipped-CAIPI sampling strategy for EPI.
• To enable flexible selection of EPI factor and phase encode bandwidth, independent of the CAIPI pattern.

Main Methods:

• Developed a skipped-CAIPI sampling strategy applicable to any blipped-CAIPI trajectory.
• Combined segmentation with controlled aliasing for enhanced flexibility.

Main Results:

• Demonstrated beneficial sampling alternatives to blipped-CAIPI and shot-selective CAIPI using temporal SNR maps.
• Showcased SNR-efficient and motion-robust structural imaging with arbitrary EPI factors and minimal noise penalty.

Conclusions:

• Skipped-CAIPI sampling significantly increases protocol flexibility for high spatiotemporal resolution EPI.
• Free choice of CAIPI pattern benefits high-resolution functional and structural scans in terms of SNR and efficiency.
• The independence of sampling pattern, TE, and image matrix size optimizes functional protocol design, even at moderate resolutions.