Preliminary Clinical Application Study of Parametric X-rays in Diagnostic Imaging

Abstract

　Parametric radiation-based X-ray (PXR), one of the pioneering modalities using an accelerator, is being studied as a new kind of X-ray source in the Laboratory for Electron Beam Research and Application Institute of Quantum Science (LEBRA). The purpose of this study was to evaluate the potential of LEBRA-PXR as a new X-ray source for diagnostic imaging.
　Dog mandibular tissue with malignant melanoma was examined. Simple X-ray images were taken with LEBRA-PXR at several wavelengths(12 keV, 15 keV, 18 keV, 21 keV, 24 keV, 27 keV, 30 keV). An energy subtracted image was generated with the image with the longest wavelength PXR and the image with the shortest wavelength PXR. As a control, an image was taken with conventional X-ray(40 kV, 125 mA, 40 msec; effective energy 21 keV). Simple X-ray images were taken with LEBRA-PXR, and the energy subtracted and conventional X-ray images were compared with the histopathological stained images.
　Compared to conventional X-ray images, LEBRA-PXR images showed contrast related to different wavelengths, reflecting histological differences between tissues. Compared with the histological findings, malignant tumor images with LEBRA-PXR were clearer than conventional X-ray images.
　Using LEBRA-PXR, a type of nearly perfectly monochromatic X-ray source imaging, the images of the malignant tumor displayed different contrasts from conventional X-ray images. LEBRA-PXR is a useful diagnostic imaging tool using a new X-ray source.