Short T2 contrast with three-dimensional ultrashort echo time imaging.

Area of Science:

• Biomedical Imaging
• Magnetic Resonance Imaging (MRI)

Background:

• Conventional magnetic resonance (MR) pulse sequences struggle to image short T2 species due to minimal signal.
• There is a growing need for advanced MR techniques to visualize tissues with very short transverse relaxation times (T2).

Purpose of the Study:

• To evaluate the utility of three-dimensional ultrashort echo time (3D UTE) sequences for imaging short T2 species.
• To explore various contrast generation methods using 3D UTE sequences for enhanced visualization.

Main Methods:

• Utilized 3D UTE sequences with echo times (TEs) as low as 8 μs.
• Employed multiple contrast techniques including dual echo subtraction, rescaled subtraction, long T2 saturation, and adiabatic inversion recovery.
• Evaluated feasibility on a 3-T clinical MR scanner for both in vitro and in vivo samples.

Main Results:

• Demonstrated the feasibility of 3D UTE sequences for imaging various short T2 tissues: calcified cartilage, aponeuroses, menisci, tendons, ligaments, and cortical bone.
• Compared different 3D UTE acquisition strategies using signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR).

Conclusions:

• 3D UTE sequences are effective for imaging tissues with short T2 relaxation times, overcoming limitations of conventional MR.
• The developed contrast techniques show promise for clinical applications in visualizing challenging anatomical structures.