Related Experiment Video
Updated: Aug 23, 2026
Pulmonary Structural MRI using Free-Breathing, Self-Gated Ultra-short Echo Time Imaging
Published on: September 6, 2024
Single-shot half-Fourier RARE sequence with ultra-short inter-echo spacing for lung imaging
Yoshiharu Ohno1, Koichi Oshio, Hidemasa Uematsu
1Pulmonary Functional Imaging Research, Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, PA, USA. yosirad@kobe-u.ac.jp
Purpose:
To improve the image quality of pulmonary magnetic resonance (MR) imaging using an ultra-short inter-echo spacing half-Fourier single shot rapid acquisition with relaxation enhancement (USHA-RARE) sequence.
Materials And Methods:
Pulmonary MR images were acquired by USHA-RARE sequence with various inter-echo spacings. The sequence parameters were as follows: repetition time (TR)/effective TE: infinite/39-41 msec; section thickness: 10 mm; acquisition matrix: 128 x 128; field of view: 450 x 450 mm. Inter-echo spacing varied (2.5 msec, 3.0 msec, 3.5 msec, 4.0 msec, 4.5 msec, 5.0 msec), and the respective phase-encoding steps were 80, 77, 75, 74, 73, and 72. Signal-to-noise ratios (SNRs), the signal ratios between lung and fat (lung-to-fat ratio: LFRs), and the signal ratios between the lung and the serratus anterior muscle (lung-to-muscle ratio: LMRs) of each inter-echo spacing were calculated, and statistically evaluated.
Results:
The SNRs at inter-echo spacings of < or = 3.0 msec were significantly higher than those > or = 4.0 msec (P < 0.05). The LFRs and LMRs at inter-echo spacing < or = 3.0 msec were significantly higher than those > or = 4.0 msec (P < 0.05).
Conclusion:
USHA-RARE sequence does improve signal intensity from the lung.
