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Simultaneous PET-MRI: a new approach for functional and morphological imaging


Noninvasive imaging at the molecular level is an emerging field in biomedical research. This paper introduces a new technology synergizing two leading imaging methodologies: positron emission tomography (PET) and magnetic resonance imaging (MRI). Although the value of PET lies in its high-sensitivity tracking of biomarkers in vivo, it lacks resolving morphology. MRI has lower sensitivity, but produces high soft-tissue contrast and provides spectroscopic information and functional MRI (fMRI). We have developed a three-dimensional animal PET scanner that is built into a 7-T MRI. Our evaluations show that both modalities preserve their functionality, even when operated isochronously. With this combined imaging system, we simultaneously acquired functional and morphological PET-MRI data from living mice. PET-MRI provides a powerful tool for studying biology and pathology in preclinical research and has great potential for clinical applications. Combining fMRI and spectroscopy with PET paves the way for a new perspective in molecular imaging.

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Figure 1: Integration of the multislice PET scanner into a 7-T MRI apparatus.
Figure 2: PET-MRT in vivo tumor study.
Figure 3: PET-MRT in vivo brain study.
Figure 4: Evaluation of magnetic resonance spectroscopy.

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This work was funded by the US National Institutes of Health (R21 grant no. EB004483-01 to B.J.P.). M.R. was supported by SFB 685. We acknowledge support from R. Ladebeck, R. Krieg, G. Schnur and W. Renz, as well as the help of B.K. Swann, B. Atkins, D. Pressley, A. McFarland and M. Lenox. We would like to thank F. Cay, D. Bukala and S. Wiehr for their excellent technical assistance and animal handling support.

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M.S.J., H.F.W., S.R.C., C.D.C. and B.J.P. designed the research. M.S.J., H.F.W., D.F.N., C.C., M.B., A.T., M.P.L., R.E.N., S.B.S., S.W., K.U. and B.J.P. performed research and analyzed the data. G.R. and H.-J.M. provided the PET tracers. M.K. and M.R. provided the mouse model. K.K. analyzed the histology and M.E. performed the statistical analyses. B.J.P. wrote the manuscript and all authors edited the manuscript.

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Correspondence to Bernd J Pichler.

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Competing interests

D.F.N., S.B.S. and R.E.N. are employees of Siemens Medical Solutions, and M.B. and S.W. are employees of Bruker Biospin MRI, both companies that manufacture small-animal imaging devices. In addition, S.R.C., C.D.C. and B.J.P. receive research support from Siemens Medical Solutions in the research fields of preclinical imaging and clinical MRI-PET development.

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Supplementary Figs. 1–15 and Supplementary Notes (PDF 3642 kb)

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Judenhofer, M., Wehrl, H., Newport, D. et al. Simultaneous PET-MRI: a new approach for functional and morphological imaging. Nat Med 14, 459–465 (2008).

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