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

摘要

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 (DeltaSI), 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-slice-selective IR pulses (P < 0.05). At TI 800 ms, the DeltaSI 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.