Imaging performance of a multimodal module to enhance preclinical irradiator capabilities

This article highlights the performance measurements of an optical device which aims at upgrading preclinical irradiators. The evaluated device allows acquiring X-ray as well as bioluminescence images with a\r\nsingle sensor. The latter consists of a supercooled camera equipped with a 1024x1024 charge coupling\r\ndevice (each element measuring 13x13µm²). X-ray imaging is feasible, thanks to a conversion phosphor\r\nscreen. Phantom acquisitions revealed a spatial resolution of 2.5 line pairs per millimetre (0.2mm) for Xray imaging and between 0.4 and 0.7mm for bioluminescence images. Image homogeneity was 0.8 for\r\nradiographic images with preclinical imaging parameters and higher than 0.9 for optical images. For\r\nfunctional imaging, contrast to noise ratio (CNR) ranged from 1.3 (for contrast of 2:1 and 0.1s acquisition)\r\nup to 253 (for contrast of 32:1 and 5s acquisition). CNR was related to acquisition duration. The device’s\r\noverall performance revealed that it is suitable to upgrade existing irradiators and improve laboratory\r\ncapabilities toward image-guided radiotherapy.