RT Journal Article SR Electronic T1 Cardiac and Respiratory Motion Correction for Simultaneous Cardiac PET/MR JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 846 OP 852 DO 10.2967/jnumed.115.171728 VO 58 IS 5 A1 Christoph Kolbitsch A1 Mark A. Ahlman A1 Cynthia Davies-Venn A1 Robert Evers A1 Michael Hansen A1 Devis Peressutti A1 Paul Marsden A1 Peter Kellman A1 David A. Bluemke A1 Tobias Schaeffter YR 2017 UL http://jnm.snmjournals.org/content/58/5/846.abstract AB Cardiac PET is a versatile imaging technique providing important diagnostic information about ischemic heart diseases. Respiratory and cardiac motion of the heart can strongly impair image quality and therefore diagnostic accuracy of cardiac PET scans. The aim of this study was to investigate a new cardiac PET/MR approach providing respiratory and cardiac motion–compensated MR and PET images in less than 5 min. Methods: Free-breathing 3-dimensional MR data were acquired and retrospectively binned into multiple respiratory and cardiac motion states. Three-dimensional cardiac and respiratory motion fields were obtained with a nonrigid registration algorithm and used in motion-compensated MR and PET reconstructions to improve image quality. The improvement in image quality and diagnostic accuracy of the technique was assessed in simultaneous 18F-FDG PET/MR scans of a canine model of myocardial infarct and was demonstrated in a human subject. Results: MR motion fields were successfully used to compensate for in vivo cardiac motion, leading to improvements in full width at half maximum of the canine myocardium of 13% ± 5%, similar to cardiac gating but with a 90% ± 57% higher contrast-to-noise ratio between myocardium and blood. Motion correction led to an improvement in MR image quality in all subjects, with an increase in sharpness of the canine coronary arteries of 85% ± 72%. A functional assessment showed good agreement with standard MR cine scans with a difference in ejection fraction of −2% ± 3%. MR-based respiratory and cardiac motion information was used to improve the PET image quality of a human in vivo scan. Conclusion: The MR technique presented here provides both diagnostic and motion information that can be used to improve MR and PET image quality. Reliable respiratory and cardiac motion correction could make cardiac PET results more reproducible.