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Updated: Jun 15, 2026
Phase Contrast Magnetic Resonance Imaging in the Rat Common Carotid Artery
Published on: September 5, 2018
Accelerating non-contrast-enhanced MR angiography with inflow inversion recovery imaging by skipped phase encoding
Zheng Chang1, Qing-San Xiang, Hao Shen
1Department of Radiation Oncology, Duke University, Durham, North Carolina 27710, USA. zheng.chang@duke.edu
Purpose:
To accelerate non-contrast-enhanced MR angiography (MRA) with inflow inversion recovery (IFIR) with a fast imaging method, Skipped Phase Encoding and Edge Deghosting (SPEED).
Materials And Methods:
IFIR imaging uses a preparatory inversion pulse to reduce signals from static tissue, while leaving inflow arterial blood unaffected, resulting in sparse arterial vasculature on modest tissue background. By taking advantage of vascular sparsity, SPEED can be simplified with a single-layer model to achieve higher efficiency in both scan time reduction and image reconstruction. SPEED can also make use of information available in multiple coils for further acceleration. The techniques are demonstrated with a three-dimensional renal non-contrast-enhanced IFIR MRA study.
Results:
Images are reconstructed by SPEED based on a single-layer model to achieve an undersampling factor of up to 2.5 using one skipped phase encoding direction. By making use of information available in multiple coils, SPEED can achieve an undersampling factor of up to 8.3 with four receiver coils. The reconstructed images generally have comparable quality as that of the reference images reconstructed from full k-space data.
Conclusion:
As demonstrated with a three-dimensional renal IFIR scan, SPEED based on a single-layer model is able to reduce scan time further and achieve higher computational efficiency than the original SPEED.
Insights
This study introduces a faster MR angiography (MRA) technique called Skipped Phase Encoding and Edge Deghosting (SPEED) for non-contrast imaging. The enhanced SPEED method significantly reduces scan times while maintaining image quality for improved renal MRA.
Area of Science:
- Medical Imaging
- Magnetic Resonance Imaging
- Angiography
Background:
- Non-contrast-enhanced MR angiography (MRA) is crucial for visualizing blood vessels.
- Inflow inversion recovery (IFIR) enhances arterial signal but can be time-consuming.
- Accelerating MRA techniques is essential for clinical efficiency.
Purpose of the Study:
- To accelerate non-contrast-enhanced MRA using IFIR with a novel fast imaging method, Skipped Phase Encoding and Edge Deghosting (SPEED).
- To evaluate the efficiency and image quality of the enhanced SPEED technique.
Main Methods:
- IFIR imaging utilizes an inversion pulse to suppress static tissue signals, highlighting arterial blood.
- The SPEED method leverages vascular sparsity for simplified modeling and efficient reconstruction.
- Multi-coil information is incorporated into SPEED for further acceleration.
Main Results:
- SPEED with a single-layer model achieved undersampling factors up to 2.5.
- Utilizing multi-coil data, SPEED achieved undersampling factors up to 8.3.
- Reconstructed images demonstrated comparable quality to full k-space data.
Conclusions:
- The enhanced SPEED method, based on a single-layer model, significantly reduces scan time for 3D renal IFIR MRA.
- This approach offers higher computational efficiency compared to the original SPEED technique.
- The findings support SPEED as a valuable tool for accelerating non-contrast MRA.
