Fig. 2.

(A) The apparent ⁸³Kr spin polarization P_app as a function of SEOP cell pressure using the extraction unit for compression (open circles) and baseline data without the extraction unit (filled circles). The arrow indicates the pressure used for imaging experiments. Curve fitting was adapted from ref. [20]. (B) Variable flip angle (VFA) FLASH hp ⁸³Kr MRI of an excised rat lungs at 9.4 T without signal averaging (NEX = 1, no slice selection, SNR = 51) using isotopically enriched ⁸³Kr (99.925%).