Peripheral Non-Contrast MR Angiography Using FBI: Scan Time and T2 Blurring Reduction with 2D Parallel Imaging

Area of Science:

• Radiology
• Medical Imaging
• Cardiovascular Imaging

Background:

• Non-contrast magnetic resonance angiography (NC-MRA) is crucial for evaluating peripheral artery disease (PAD).
• Fresh blood imaging (FBI) is a key NC-MRA technique, with standard (sFBI) and centric (cFBI) acquisitions offering different trade-offs.
• Optimizing scan time and image quality in FBI is essential for effective PAD assessment.

Purpose of the Study:

• To evaluate standard FBI (sFBI) and centric ky-kz FBI (cFBI) using 1D and 2D parallel imaging factors (PIFs).
• To assess the impact of PIFs on scan time, image quality, and vessel measurements in PAD imaging.
• To determine the optimal FBI technique and PIF strategy for balancing speed and diagnostic accuracy.

Main Methods:

• Four volunteers underwent bilateral leg imaging using sFBI and cFBI sequences with 1D and 2D PIFs.
• Image quality was assessed by a radiologist, with signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) measured.
• Vessel width was measured on coronal maximum intensity projections (MIPs), including standard and 80-degree MIPs.

Main Results:

• cFBI significantly reduced scan times compared to sFBI (98–162 s vs. 184–206 s).
• All techniques demonstrated similar SNRs and CNRs, with no significant differences in overall image quality or standard MIP vessel width.
• 80-degree MIP showed wider vessels with cFBI and 1D PIF, indicating a trade-off in T2 blurring, particularly with 1D PIF.

Conclusions:

• FBI-based techniques are valuable for peripheral artery imaging in PAD.
• Centric ky-kz FBI with 2D PIF provides a favorable balance between reduced scan time and good image sharpness in multiple planes.
• Optimizing PIF strategies is crucial for maximizing diagnostic utility in NC-MRA for PAD.