Spin echo and gradient echo quantification in oxygen enhanced MRI may yield different results

Pulmonary oxygen enhanced MRI is currently performed with a variety of pulse sequences. This abstract provides evidence that the oxygen enhancement, quantified as the change in longitudinal relaxation rate, ΔR1, assessed with a spin-echo or gradient-echo sequence may yield different values. Indeed, a standard IR-HASTE quantification yielded group mean ΔR1 10% higher than the Snapshot-FLASH quantification in 15 healthy volunteers. Although studies employing different quantification schemes are likely comparable, caution is warranted since the mean ΔR1 quantified with HASTE-type sequences is likely higher.