Accelerated aortic 4D flow cardiovascular magnetic resonance using compressed sensing: applicability, validation and...

Area of Science:

• Cardiovascular Imaging
• Medical Physics
• Biomedical Engineering

Background:

• Three-dimensional time-resolved phase-contrast cardiovascular magnetic resonance (4D flow CMR) allows blood flow quantification and visualization.
• Clinical application of 4D flow CMR is limited by prolonged scan times.

Purpose of the Study:

• To evaluate the efficacy of compressed sensing (CS) with on-line reconstruction for accelerating 4D flow CMR acquisition and reconstruction of the thoracic aorta.

Main Methods:

• 4D flow CMR of the thoracic aorta was performed in 20 healthy subjects using CS with acceleration factors from 4 to 10, compared against SENSE (acceleration factor 2).
• Flow curves, net flows, peak flows, and peak velocities were extracted; particle trace analysis assessed internal data consistency.
• Scan-rescan, inter-, and intraobserver reproducibility were evaluated, with subsequent qualitative analysis in 3 patients with aortopathies using CS factor 6.

Main Results:

• On-line acquisition and reconstruction were successful. Average acquisition time with CS factor 6 was 5:02 ± 2:23 min; reconstruction took ~9 min.
• For CS factors ≤8, mean differences in net flow, peak flow, and peak velocity compared to SENSE were within acceptable limits.
• Scan-rescan analysis for CS factor 6 showed minimal mean difference in net flow (-0.2 ± 8.5 ml/cycle).

Conclusions:

• A six- to eightfold acceleration of 4D flow CMR using CS is feasible.
• No statistically significant differences in flow parameters were observed up to a CS acceleration rate of 6 compared to the reference technique.
• The method's potential for clinical integration is confirmed by patient acquisitions, offering benefits in scan-time savings and on-line reconstruction.