A System for Low Field Imaging of Laser-Polarized Noble Gas

Abstract We describe a device for performing MRI with laser-polarized noble gas at low magnetic fields ( 3 He (Larmor frequency of 67 kHz) in both sealed glass cells and excised rat lungs, using ∼0.1 G/cm gradients to achieve ∼1 mm 2 resolution. In addition, we measured 3 He T 2 * times greater than 100 ms in excised rat lungs, which is roughly 20 times longer than typical values observed at high (∼2 T) fields. We include a discussion of the practical considerations for working at low magnetic fields and conclude with evidence of radiation damping in this system.