Figure 1:

Murine model of progressive RILI. Mice underwent a single dose of 21 Gy to the right hemithorax and were imaged at either 3- or 6-months post irradiation (A). Representative H&E (top) and trichrome (bottom) stains of right lung (B) show normal lung architecture in unirradiated 0M mice. Mice at 3 months developed cellular infiltrate, alveolar thickening, consolidation, and collagen deposition. By 6 months, significant fibrosis and alveolar consolidation was seen. Representative axial MR images (C) are shown before and after EP-3533 injection. Lungs of unirradiated mice (0Gy) show low signal on UTE MR. Irradiated mice show increasing right lung signal from 3 to 6 months due to consolidation, and these areas are enhanced following EP-3533 administration. False color subtraction images (40 minutes following EP-3533 injection – preinjection) overlaid on pre-injection UTE images demonstrate increased signal enhancement in irradiated lung. Co-localization of lung injury in the irradiated right hemithorax on pathology and coronal MR images (D). Diffuse injury throughout the right lung but not in the left lung is seen on Masson’s trichrome and MR-T1FLASH image. False color subtraction image illustrates substantial signal enhancement in the right lung but not in the non-irradiated left lung.