Highly accelerated cardiac MRI using iterative SENSE reconstruction: initial clinical experience.

Area of Science:

• Cardiovascular Magnetic Resonance Imaging (CMR)
• Medical Imaging Physics
• Image Reconstruction Techniques

Background:

• Accelerated cardiovascular MRI (CMR) protocols are crucial for reducing scan times and improving patient comfort.
• Standard parallel imaging techniques like GRAPPA have limitations in acceleration factors.
• Novel reconstruction methods are needed to achieve higher acceleration while preserving image quality.

Purpose of the Study:

• To evaluate the qualitative and quantitative performance of an accelerated CMR protocol using iterative SENSE reconstruction with spatio-temporal L1-regularization (IS SENSE).
• To compare IS SENSE against standard GRAPPA and TSENSE techniques at acceleration factor 4.
• To assess image quality, acquisition times, and diagnostic accuracy for cardiac function and wall motion.

Main Methods:

• 2D steady-state free precession cine images were acquired in 20 patients and 9 volunteers using GRAPPA (acc. factor 2), TSENSE (acc. factor 4), and IS SENSE (acc. factor 4).
• Acquisition times, quantitative cardiac function (ejection fraction), wall motion abnormalities (WMA), and qualitative image quality (noise, artifacts) were analyzed.
• Statistical comparisons were performed between the three techniques.

Main Results:

• IS SENSE and TSENSE significantly reduced breath-hold times (3.0 ± 0.6 s and 3.3 ± 0.6 s) compared to GRAPPA (8.4 ± 1.7 s) (p < 0.001).
• No significant differences in quantitative cardiac function (e.g., ejection fraction) were observed between techniques (p = 0.89).
• IS SENSE and GRAPPA demonstrated superior image quality (4.5 ± 0.6 and 4.7 ± 0.4) compared to TSENSE (4.1 ± 0.7) (p < 0.001), with good WMA agreement for IS SENSE (κ > 0.60).

Conclusions:

• Iterative SENSE (IS SENSE) is a clinically viable approach for accelerating cardiovascular MRI acquisition.
• The technique effectively reduces scan times without compromising quantitative cardiac function assessment or diagnostic image quality.
• IS SENSE offers a promising alternative for faster and more efficient CMR examinations.