Oxygen-enhanced lung magnetic resonance imaging: Influence of inversion pulse slice selectivity on inversion recovery half-Fourier single-shot turbo spin-echo signal

Purpose. The purpose of this study was to evaluate in vivo the influence of inversion pulse slice selectivity on oxygen-enhanced magnetic resonance imaging (MRI). Materials and methods. Thirteen healthy volunteers were studied with a two-dimensional cardiac- and respiratory-gated adiabatic inversion-recovery half-Fourier single-shot turbo spin-echo (HASTE) sequence with either slice-selective or non-slice-selective inversion recovery (IR) pulse at inversion times increasing from 300 to 1400 ms. The signal-to-noise ratio (SNR) at every inversion time (TI), real signal difference (ΔSI), and relative enhancement ratio of lung parenchyma at TI ≥ 800 ms were statistically compared for oxygen-enhanced and non-oxygen-enhanced MR images with slice-selective or non-slice-selective IR pulses. Results. The SNRs of acquisitions with slice-selective IR pulses were significantly higher than those of non-sliceselective IR pulses (P < 0.05). At TI 800 ms, the ΔSI of lung parenchyma on IR-HASTE images with slice-selective inversion pulse type was significantly higher than on that with the non-slice-selective type (P < 0.05). Relative enhancement ratios of the slice-selective IR pulses were significantly lower than those of non-slice-selective IR pulses at TIs between 800 and 1400 ms (P < 0.05). Conclusion: Slice selectivity of inversion pulse type affects oxygen-enhanced MRI in vivo.