UTE imaging with simultaneous water and fat signal suppression using a time-efficient multispoke inversion recovery...

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Biomedical Engineering
• Radiology

Background:

• Ultrashort echo time (UTE) MRI sequences with inversion recovery preparation often result in prolonged scan durations.
• Efficient suppression of long T2 signals is crucial for enhancing contrast of short T2 tissues.

Purpose of the Study:

• To develop and validate an optimized method for long T2 signal suppression in inversion recovery 3D UTE imaging.
• To reduce scan times while maintaining or improving image quality for short T2 tissue visualization.

Main Methods:

• A multispoke acquisition strategy was implemented after each inversion preparation pulse.
• Bloch equations were used to optimize sequence parameters, including inversion time (TI) and flip angle, for signal suppression and contrast maximization.
• A three-dimensional (3D) UTE Cones acquisition was employed with Silver-Hoult adiabatic inversion pulses.

Main Results:

• The multispoke inversion recovery method demonstrated effective suppression of muscle and fatty bone marrow (long T2 signals).
• Short T2 signals, such as those from the femoral and tibial cortex, were clearly highlighted.
• Experimental results on a healthy volunteer confirmed theoretical predictions regarding signal suppression and contrast enhancement.

Conclusions:

• Inversion recovery 3D UTE imaging with multispoke acquisitions offers an effective approach for suppressing long T2 signals and visualizing short T2 tissues within practical clinical scan times.
• Theoretical modeling is a valuable tool for optimizing sequence parameters to achieve desired signal suppression and contrast.