De-aliasing for signal restoration in Propeller MR imaging

Area of Science:

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

Background:

• Propeller imaging is susceptible to unique aliasing artifacts from objects outside the field-of-view.
• These artifacts manifest as signal loss and distortions, particularly at image peripheries.

Purpose of the Study:

• To develop and validate a de-aliasing approach for Propeller MRI.
• To restore signal intensities in aliased images without necessitating extra data acquisition.

Main Methods:

• Computer simulations using the Shepp-Logan head phantom were conducted to analyze signal aliasing.
• Phantom and human imaging experiments were performed on a 3.0 Tesla MR scanner using Propeller imaging.
• A de-aliasing method was applied, utilizing the first low-resolution single-blade image to identify aliasing patterns for subsequent reconstruction.

Main Results:

• Simulations accurately predicted signal loss and aliasing artifacts consistent with clinical observations.
• The proposed de-aliasing method successfully restored image quality in both phantom and human experimental data.
• Restored images demonstrated accurate signal intensities compared to uncorrected Propeller images.

Conclusions:

• The de-aliasing operation serves as an effective adjunct to standard Propeller MRI reconstruction.
• This method allows for retrospective restoration of aliased signals, improving diagnostic accuracy.
• The technique offers a valuable solution for mitigating artifacts in Propeller imaging.