NONINVASIVE DIGITAL ENERGY SUBTRACTION ANGIOGRAPHY WITH A CHANNELING-RADIATION X-RAY SOURCE

Channeling radiation could provide a viable source for digital energy subtraction angiography (DESA). A signal to noise ratio (SNR) of 6.2 f or a resolution of 0.5 mm X 0.5 mm could be achieved using a 6-mA 100- ms 20-MeV electron-beam pulse and a diamond channeling crystal as the x-ray source. This article investigates the choice of a DESA contrast agent and the parameters of a channeling-radiation x-ray source to dev elop a channeling-radiation DESA imaging system. The production of dua l-energy peaks, the maximum available x-ray flux, the advantages of an area exposure, the necessity of a mosaic Bragg-crystal filter to redu ce patient dose, the optimal energy separation of the peaks for a quas imonochromatic x-ray source, and the reduction of the signal from bone are discussed, leading to estimated SNRs and image resolution for a c hanneling-radiation imaging system. The computer analysis developed to calculate the image quality is also discussed.