Magnetic resonance imaging with gradient sound respiration guide

Area of Science:

• Medical Imaging
• Biophysics
• Cardiovascular and Respiratory Systems

Background:

• Respiratory motion significantly degrades MRI quality, especially for high-resolution scans of thoracic and abdominal organs.
• Current respiratory motion management techniques include retrospective gating, k-space navigators, and image-based self-gating.
• Effective motion management is critical for accurate diagnosis and visualization in pulmonary and renal MRI.

Purpose of the Study:

• To introduce and validate a novel respiration guidance method using acoustic sound generated by pulsed gradient waveforms.
• To compare the performance of sound-guided respiration with existing respiratory motion management techniques in ultrashort echo time (UTE) MRI.
• To assess the feasibility of sound-guided respiration for non-contrast enhanced renal angiography.

Main Methods:

• Developed a sound-guided respiration system using sinusoidal gradient waveforms at 602 and 321 Hz to provide breathing instructions.
• Implemented the sound-guided respiration in pulmonary UTE sequences and stack-of-stars balanced steady-state free precession for renal angiography.
• Evaluated image quality by measuring the sharpness of the lung-liver interface (w10-90) and comparing it with no gating, k-point navigator, and image-based self-gating.

Main Results:

• Sound-guided respiration significantly improved lung-liver interface sharpness (w10-90 = 6.99 ± 2.90 mm) compared to no gating (17.13 ± 2.91 mm).
• Image sharpness with sound-guided respiration was comparable to image-based self-gating (7.01 ± 2.06 mm) and k-point navigator (8.51 ± 2.71 mm).
• Sound-guided respiration provided better visualization of pulmonary vasculature and clearly delineated renal arteries in angiography, with no reported patient discomfort.

Conclusions:

• Gradient sound-guided respiration is an effective technique for managing respiratory motion in MRI.
• This method ensures consistent diaphragm positioning, leading to improved image quality comparable to advanced gating techniques.
• Sound-guided respiration offers a promising, non-invasive approach for high-resolution pulmonary and renal MRI, enhancing diagnostic visualization.