A colon imaging system, including an imaging capsule, having: a. a radiation source providing X-Ray and gamma radiation with energies sufficient to induce X-Ray fluorescence from nanoparticles that adhere to cancerous tissue, and which were administered to a patient in a solution prior to examining the colon with the imaging capsule b. a detector for detecting particle energy of particles emitted responsive to the provided radiation and forming count information disclosing a number of particles detected for each energy level c. a transceiver for transferring the count information to an external computer for analysis, and also having a computer for constructing images of an inside of the colon based on the count information wherein the images provide an indication of locations in the colon of which the nanoparticles adhere to.
