Abstract #1334

Santyr G, Lam W, Ouriadov A, Drangova M, McCormack D, Holdsworth D

Hyperpolarized helium gas can be used to measure regional ventilation in the rodent lung, however, this approach requires knowledge and or assumptions involving spin-lattice relaxation, T1, of the gas in the ventilator system and in the lung; the latter requiring knowledge of the alveolar oxygen partial pressure. An established method for regional ventilation mapping is xenon-enhanced CT, which is independent of relaxation effects. In this work, helium MR imaging and xenon-enhanced CT imaging of ventilation are compared in rats. The results indicate that ventilation measurements obtained by helium MR are comparable to xenon-enhanced CT without the associated x-ray dose.