System and method for radiological image formation

An image-forming system for radiological imaging consisting of an intensifying screen comprising on a support at least one layer of a green-light emitting phosphor and, in operative association therewith, a prehardened light-sensitive photographic silver halide film material, comprising a support and on both sides thereof one or more hydrophilic colloid layers, said layers being hardened to such an extent that their swelling degree is reduced to less than 200% after immersing said material for 2 minutes in demineralized water of 35.degree. C.;

• further comprising in at least one of said hydrophilic layers chemically ripened, monodisperse essentially cubic silver chloroiodide grains having iodine introduced up to a concentration of 0.2 mol % vs, silver before chemically ripening said grains having a mean crystal diameter of from 0.40 .mu.m up to 0.65 .mu.m;
• wherein said grains have been spectrally sensitized in the wavelength range between 520 and 580 nm, have a maximum absorption between 540 and 500 nm and have been coated in a total amount of silver per sq.m. of from 6 g up to 8 g, wherein said amount is expressed as an equivalent amount of silver nitrate per sq.m.;
• said image-forming system being characterized in that said silver chloroiodide grains have been doped with a complex ion compound satisfying formula (I)
• [ML.sub.6 ].sup.n- (I)
• wherein
• M represents a filled frontier orbital polyvalent metal ion;
• L.sub.6 represents six coordination complex ligands which are independently selected, provided that at least three of the said ligands are more electronegative than any halide ligand and at least four of the said ligands are anionic ligands;
• n=1, 2, 3 or 4;
• wherein the energetic distance between filled higher occupied (HOMO) and lower unoccupied (LUMO) molecular orbital is more than 27000 cm.sup.-1 and wherein said complex ion compound is present between addition from 80 to 90% of the total amount of silver in the preparation of said silver chloroiodide grains;
• and said cubic silver chloroiodide grains having been spectrally sensitized with a combination of imidacarbocyanine and oxacarbocyanine.