%0 Journal Article %A Bernd J. Pichler %A Martin S. Judenhofer %A Ciprian Catana %A Jeffrey H. Walton %A Manfred Kneilling %A Robert E. Nutt %A Stefan B. Siegel %A Claus D. Claussen %A Simon R. Cherry %T Performance Test of an LSO-APD Detector in a 7-T MRI Scanner for Simultaneous PET/MRI %D 2006 %J Journal of Nuclear Medicine %P 639-647 %V 47 %N 4 %X PET combined with CT has proven to be a valuable multimodality imaging device revealing both functional and anatomic information. Although PET/CT has become completely integrated into routine clinical application and also has been used in small-animal imaging, CT provides only limited soft-tissue contrast and, in preclinical studies, exposes the animal to a relatively high radiation dose. Unlike CT, MRI provides good soft-tissue contrast even without application of contrast agents and, furthermore, does not require ionizing radiation. Methods: This project focused on combining a high-resolution PET scanner with a 7-T MRI system for animal research. Because classic PET detectors based on photomultiplier tubes cannot be used in high magnetic fields, we used a detector technology based on 10 × 10 lutetium oxyorthosilicate crystal arrays and 3 × 3 avalanche photodiode arrays. A ring of such PET detectors will ultimately be used as an insert for the 119-mm-diameter MRI bore. Results: Initial measurements with 1 PET detector module in the 7-T field during application of MRI sequences were encouraging. Position profiles from the PET detectors and a first MR image of a mouse could be acquired simultaneously. Conclusion: Further work will concentrate on the construction of a full PET detector ring with compact, integrated electronics. %U https://jnm.snmjournals.org/content/jnumed/47/4/639.full.pdf