3D Hyperpolarized (129)Xe MRI of mouse lung at low xenon concentration using a continuous flow-type hyperpolarizing system: feasibility for quantitative measurement of regional ventilation.

摘要: Purpose: We investigated the feasibility of 3D hyperpolarized (HP) 129Xe magnetic resonance (MR) imaging at an extremely low concentration HP supplied from a continuous flow-type hyperpolarizing (CF-HP) system and established standard procedure for measuring regional lung ventilation small animals, such as mouse, baseline further studies. Materials Methods: performed MR lungs 2 healthy emphysematous mice that were spontaneously breathing diluted (<1%). From three images acquired by varying flip angle radiofrequency (RF) pulse, we calculated time constant recovery, τ′rep, which represents required magnetization to be replenished approximately 63% after destruction hyperpolarization RF saturation pulse. After calculating τ′rep maps, examined validity our method. Results: used xenon CF-HP acquire mouse undiminished under spontaneous respiration. The averaged values longer than lungs, reflected defects in lung. Conclusions: This permitted us estimate any arbitrarily set slice, it will provide