Hyperpolarized 129 Xe MRI of the rat brain with chemical shift saturation recovery and spiral-IDEAL readout

• Published in: Magnetic resonance in medicine 2022-04, Vol.87 (4), p.1971-1979
• Main Authors: Friedlander, Yonni, Zanette, Brandon, Lindenmaier, Andras, Li, Daniel, Kadlecek, Stephen, Santyr, Giles, Kassner, Andrea
• Format: Article
• Language: English
• Subjects: Animals; Brain - diagnostic imaging; Lung; Magnetic Resonance Imaging - methods; Rats; Respiration; Xenon Isotopes
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.29105

To demonstrate the feasibility of Xe chemical shift saturation recovery (CSSR) combined with spiral-IDEAL imaging for simultaneous measurement of the time-course of red blood cell (RBC) and brain tissue signals in the rat brain. Images of both the RBC and brain tissue Xe signals from the brains of five rats were obtained using interleaved spiral-IDEAL imaging following chemical shift saturation pulses applied at multiple CSSR delay times, τ. A linear fit of the signals to τ was used to calculate the slope of the signal for both RBC and brain tissue compartments on a voxel-by-voxel basis. Gas transfer was evaluated by measuring the ratio of the whole brain tissue-to-RBC signal intensities as a function of τ. To investigate the relationship between the CSSR images and gas transfer in the brain, the experiments were repeated during hypercapnic ventilation. Hypercapnia, affected the ratio of the tissue-to-RBC signal intensity (p = 0.026), consistent with an increase in gas transfer. CSSR with spiral-IDEAL imaging is feasible for acquisition of Xe RBC and brain tissue time-course images in the rat brain. Differences in the time-course of the signal intensity ratios are consistent with gas transfer changes expected under hypercapnic conditions.