As for this invention, it is possible x-ray image to do the cancer and the like uniquely, in addition, high sensitivity as the fluorescent indicator by functioning doing it designates that the x-ray absorption fluorescent nano grain which is the bimodal contrast medium which makes that also the te detects with real time making use of expensive PET image possible is offered as topic. This invention becomes, the x-ray absorption nano grain and the fluorescent nano grain being bonded, the x-ray contrast medium to which cubic measure mean particle diameter includes the x-ray absorption fluorescent compound nano grain, and the said x-ray absorption fluorescent compound nano grain below 1000nm above 10nm is offered.本発明は、がんなどを特異的にX線造影することができ、また、高感度な蛍光標識としても機能することによって高価なPET造影を用いなくてもリアルタイムでの検出を行うことを可能とするバイモーダル造影剤であるX線吸収蛍光ナノ粒子を提供することを課題とする。本発明は、X線吸収ナノ粒子と蛍光ナノ粒子が結合してなる、体積平均粒子径が10nm以上1000nm以下のX線吸収蛍光複合ナノ粒子、および該X線吸収蛍光複合ナノ粒子を含むX線造影剤を提供する。
