Accelerated MRI by SPEED with generalized sampling schemes.

Area of Science:

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

Background:

• Fast imaging techniques are crucial for reducing MRI scan times.
• Skipped phase encoding (PE) and edge deghosting (SPEED) is a method to accelerate MRI acquisition.
• Previous SPEED implementations were limited to prime numbers for PE skip size.

Purpose of the Study:

• To generalize the SPEED technique for broader sampling options and increased implementation flexibility.
• To investigate the impact of relaxing the prime number restriction on PE skip size.
• To enhance the applicability of SPEED in various MRI scenarios.

Main Methods:

• Relaxed the restriction on PE skip size from prime numbers to any integers.
• Studied various sampling patterns with different PE skip sizes and PE shifts.
• Introduced a criterion based on ghost phasor matrix rank for evaluating SPEED reconstruction quality.

Main Results:

• Reconstruction quality is dependent on the ghost phasor matrix rank and the skipped PE size.
• Low rank values indicate matrix singularity and potential reconstruction failure.
• Satisfactory reconstruction was achieved using composite numbers for PE skip size with appropriate PE shifts.

Conclusions:

• Any integer, including composite numbers, can be used as PE skip size for SPEED with proper PE shifts.
• This generalization significantly increases flexibility in data acquisition for MRI.
• The findings enable more freedom in practical implementations and applications of fast MRI techniques.