Quantifying errors in flow measurement using phase contrast magnetic resonance imaging: comparison of several...

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Cardiovascular Flow Dynamics

Background:

• Accurate quantification of blood flow using phase-contrast MRI (PC-MRI) depends heavily on precise vessel segmentation.
• Existing error models for flow quantification are complex and difficult to apply practically.

Purpose of the Study:

• To simplify existing mathematical expressions for flow quantification errors.
• To develop practical criteria for minimizing segmentation-related errors in PC-MRI flow measurements.

Main Methods:

• Simplified mathematical expressions for flow quantification errors were derived using realistic assumptions.
• Numerical simulations were performed to assess the impact of segmentation accuracy on flow quantification.
• Four segmentation methods were evaluated on simulated and phantom MRA data.

Main Results:

• Including partial volume edge pixels in segmentation generally reduces flow quantification error.
• To achieve <10% (<5%) flow error, vessels require a diameter of at least 4 (5) pixels.
• A signal-to-noise ratio (SNR) of at least 10:1 and a peak velocity to saturation cut-off velocity ratio of at least 5:3 are recommended.

Conclusions:

• Simplified error models provide practical criteria for accurate PC-MRI flow quantification.
• Segmentation strategies that incorporate partial volume effects and meet defined imaging parameter thresholds are essential for reliable results.