Some of the most important techniques for the detection of heart disease involve the use of radioactive tracers. These tracers yield information on cardiac chamber volumes, cardiac output, ejection fractions, regional perfusion patterns, and zones of frank tissue damage. GNL Associates, Inc. proposes to develop an alternative tracer technology that does not require the injection of radionuclides into the circulatory system, but rather is based upon an x-ray-induced fluorescence of iodine present in commonly used radiographic contrast agents.These iodine concentrations will be tracked with a new type of radiation-detection system that has high resolution in both space and energy. The two-way high resolution is achieved with a dual solid-state detector system consisting of an ion-implanted, resistive, silicon detector (high spatial resolution) and an ultrapure germanium detector (high energy resolution). By using offthe-shelf technology in a new way, it is expected that this system can be developed at a considerably lower cost than current radioisotope scanning systems. Such a device also has the commercial potential for nonmedical uses.National Heart, Lung, and Blood Institute (NHLBI)
