Undersampled elliptical centric view-order for improved spatial resolution in contrast-enhanced MR angiography

Area of Science:

• Magnetic Resonance Imaging
• Medical Imaging
• Radiology

Background:

• Contrast-enhanced MR angiography (CE-MRA) is a standard clinical tool.
• There is a persistent need for higher spatial resolution in CE-MRA within practical acquisition times.
• Existing techniques like undersampled projection reconstruction (PR) and elliptical centric (EC) view order offer partial solutions.

Purpose of the Study:

• To introduce and evaluate a novel hybrid elliptical centric-projection reconstruction (EC-PR) technique.
• To demonstrate that EC-PR can enhance spatial resolution compared to standard EC methods.
• To validate the diagnostic adequacy of EC-PR in clinical CE-MRA applications.

Main Methods:

• Developed a hybrid EC-PR technique by undersampling the periphery of the k(Y)-k(Z) plane in an EC acquisition.
• Reconstructed images using standard 3D Fourier Transform (3DFT) on a rectilinear grid.
• Compensated for missing k-space data using zero-filling or 2D homodyne reconstruction.

Main Results:

• Point spread function analysis and phantom experiments showed approximately twofold resolution improvement with EC-PR compared to fully sampled data.
• Clinical testing in 11 CE-MRA studies of popliteal and carotid arteries confirmed improved resolution.
• Diagnostic image quality and signal-to-noise ratio (SNR) were maintained at adequate levels (P < 0.03).

Conclusions:

• The hybrid EC-PR technique effectively enhances spatial resolution in CE-MRA.
• This method offers a valuable improvement over standard EC techniques for clinical imaging.
• EC-PR presents a promising approach for achieving higher resolution CE-MRA within clinical constraints.