The goal of this work is to develop and commercialize a new radionuclide imaging camera based on germanium detectors that will improve the detection of low contrast objects including tumors in biological and medical applications. The Phase I project will simulate the performance of a collimated germanium orthogonal strip detector (GOSD). A prototype GOSD will be fabricated and device performance, i.e. spatial and energy resolution, uniformity, and efficiency measured in response to 140 ke V gamma rays. Small, low contrast test objects will be fabricated and imaged simulated with both the germanium camera and a modern gamma camera to determine relative performance in realistic tasks. In Phase II, we will fabricate a second GOSD detector for bench tests including response to inanimate test objects. The GOSD will be tested in selected patients being investigated for tumors in which nuclear and non- nuclear imaging tests are being performed to assess its relative merits in clinical situations of commercial Anger-type gamma cameras vs. the GOSD. In Phase III, commercial considerations will determine the feasibility of attracting a partner for further development. ORTEC has expressed interest depending on the results of the investigations proposed herein. PROPOSED COMMERCIAL APPLICATION: Germanium imaging detectors can discriminate primary photons from scattered photons to a far higher degree than scintillation-based imaging systems. The greatly superior energy resolution increases detectability of small, low contrast objects, including tumors. New fabrication methods, improved electronics and experience with long term stability of germanium detectors makes then important for clinical tasks. The team includes scientists, medical and industrial workers skilled in the relevant technology.