The present invention provides improved resolution ratio and contrasts, are issued in x-ray imaging with line, and quasi- monochromatic X-ray source is used for x-ray fluorescence computer tomography. Certain types of x-ray source is suitable for emitting such line liquid-jet- anode x ray source. X-ray fluorescence is obtained, using nanoparticle, the nanoparticle and metal core that are preferably coated with. The shape of X-ray radiation from x-ray source has simultaneously filtered and is being transmitted to nanoparticle before energy dispersing optics.
