RT Journal Article SR Electronic T1 Performance Test of an LSO-APD Detector in a 7-T MRI Scanner for Simultaneous PET/MRI JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 639 OP 647 VO 47 IS 4 A1 Pichler, Bernd J. A1 Judenhofer, Martin S. A1 Catana, Ciprian A1 Walton, Jeffrey H. A1 Kneilling, Manfred A1 Nutt, Robert E. A1 Siegel, Stefan B. A1 Claussen, Claus D. A1 Cherry, Simon R. YR 2006 UL http://jnm.snmjournals.org/content/47/4/639.abstract AB 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.