Photothermographic material and image forming method using same

An image-forming combined system for medical diagnosis application comprising a combination of a photothermographic material and an X-ray intensifying screen, wherein the photothermographic material comprises:

• a support and, disposed only on one surface of the support, an image-forming layer, which comprises a non-photosensitive organic silver salt comprising silver behenate, a photosensitive silver halide comprising tabular grains, a binder, a bisphenol reduction agent, a color toning agent, an organic polyhalogen compound, and a silver iodide complex forming agent that, after thermal development, substantially reduces visible light absorption caused by the photosensitive silver halide;
• the photosensitive silver halide tabular grains have an average sphere-equivalent diameter in a range from 0.3 μm to 5.0 μm and a silver iodide content of 90 mol % to 100 mol %;
• the silver iodide complex forming agent is contained in a range from 50 to 300 mol % relative to an amount of the photosensitive silver halide;
• the silver iodide complex forming agent reduces a transition absorption of silver iodide of the photothermographic material after thermal development, which resides in the vicinity of 423 nm, to ½ or less than that before the thermal development;
• the photothermographic material is capable of being recorded imagewise by exposure using the X-ray intensifying screen,
• an exposure quantity, that is necessary for obtaining an image density of fog plus 0.5 after the steps of (1) exposing the photothermographic material with a monochromatic light having the same wavelength as the main emission peak wavelength of the X-ray intensifying screen and having a half bandwidth of 15 nm±5 nm and (2) thermally developing the photothermographic material, is in a range from 0.005 lux·second to 0.07 lux·second, and
• an image contrast after the thermal development is in a range from 3.0 to 5.0.