Chemical Shift Imaging of the lungs with hyperpolarized Xe-129: Results from a rabbit model of stereotactic lung radiosurgery with and without a radioprotector

control group (radiation only). A & B: CT scans with radiation treatment planning superimposed. Area in red received full radiation dose (3x11Gy). All animals received radiation in same location. C & D: CT scans at 8 weeks post radiation. While lung in C has homogeneous tissue density, the lung in D shows an area of hypodensity that correlates with the irradiated area (oval and arrow). E & F: ce-MRA at 8 weeks post radiation. At the same location as in the CT scan (D), the ce-MRA (F), shows evidence of low pulmonary perfusion (arrow). G & H: He-3 ventilation images at 8 weeks post radiation. Both animals present normal and homogeneous ventilation throughout both lungs. I & J: Normalized hp Xe-129 CSI maps. While the animal from the radioprotector group (I) shows a uniform distribution of the hp Xe-129 dissolved in the lung tissue (small elevation in the left lung upper lobe from pericardial fat), the animal from the control group (J) shows an elevation of the hp Xe-129 dissolved in the lung tissue due to a ventilation-perfusion mismatch caused by the radiation (arrow). Note the good correlation between the elevated area in J and the perfusion defect in F. Chemical Shift Imaging of the lungs with hyperpolarized Xe-129: Results from a rabbit model of stereotactic lung radiosurgery with and without a radioprotector.