Abstract
Objective
Positron emission tomography (PET) provides an accurate measurement of radiotracer concentration in vivo, but performance can be limited by subject motion which degrades spatial resolution and quantitative accuracy. This effect may become a limiting factor for PET studies in the body as PET scanner technology improves. In this work, we propose a new approach to address this problem by employing motion information from images measured simultaneously using a magnetic resonance (MR) scanner.
Methods
The approach is demonstrated using an MR-compatible PET scanner and PET–MR acquisition with a purpose-designed phantom capable of non-rigid deformations. Measured, simultaneously acquired MR data were used to correct for motion in PET, and results were compared with those obtained using motion information from PET images alone.
Results
Motion artefacts were significantly reduced and the PET image quality and quantification was significantly improved by the use of MR motion fields, whilst the use of PET-only motion information was less successful.
Conclusions
Combined PET–MR acquisitions potentially allow PET motion compensation in whole-body acquisitions without prolonging PET acquisition time or increasing radiation dose. This, to the best of our knowledge, is the first study to demonstrate that simultaneously acquired MR data can be used to estimate and correct for the effects of non-rigid motion in PET.
References
Wienhard K, Schmand M, Casey ME, Baker K, Bao J, Eriksson L, et al., editors. The ECAT HRRT: performance and first clinical application of the new high resolution research tomograph. 2000 IEEE Nucl Sci Symp Conf Rec; 2000.
Livieratos L, Rajappan K, Stegger L, Schafers K, Bailey DL, Camici PG. Respiratory gating of cardiac PET data in list-mode acquisition. Eur J Nucl Med Mol Imaging. 2006;33(5):584–8.
Nehmeh SA, Erdi YE, Ling CC, Rosenzweig KE, Squire OD, Braban LE, et al. Effect of respiratory gating on reducing lung motion artifacts in PET imaging of lung cancer. Med Phys. 2002;29(3):366–71.
Schafers KP, Stegger L. Combined imaging of molecular function and morphology with PET/CT and SPECT/CT: image fusion and motion correction. Basic Res Cardiol. 2008;103(2):191–9.
Nehmeh SA, Erdi YE. Respiratory motion in positron emission tomography/computed tomography: a review. Semin Nucl Med. 2008;38(3):167–76.
Nehmeh SA, Erdi YE, Meirelles GSP, Squire O, Larson SM, Humm JL, et al. Deep-inspiration breath-hold PET/CT of the thorax. J Nucl Med. 2007;48(1):22–6.
Montgomery AJ, Thielemans K, Mehta MA, Turkheimer F, Mustafovic S, Grasby PM. Correction of head movement on PET studies: comparison of methods. J Nucl Med. 2006;47(12):1936–44.
Catana C, van der Kouwe A, Benner T, Byars L, Michel C, Hamm M, et al. Rigid-body MR-assisted PET motion correction. J Nucl Med. 2009;50(Supplement 2):592.
Ruan D, Fessler JA, Balter JM. Mean position tracking of respiratory motion. Med Phys. 2008;35(2):782–92.
Ruan D, Fessler JA, Balter JM, Sonke JJ. Exploring breathing pattern irregularity with projection-based method. Med Phys. 2006;33(7):2491–9.
Dawood M, Buther F, Jiang X, Schafers KP. Respiratory motion correction in 3-D PET data with advanced optical flow algorithms. IEEE Trans Med Imaging. 2008;27(8):1164–75.
Rahmim A. Advanced motion correction methods in PET. Iran J Nucl Med. 2005;13(24):1–17.
Livieratos L, Stegger L, Bloomfield PM, Schafers K, Bailey DL, Camici PG. Rigid-body transformation of list-mode projection data for respiratory motion correction in cardiac PET. Phys Med Biol. 2005;50(14):3313–22.
Osman MM, Cohade C, Nakamoto Y, Wahl RL. Respiratory motion artifacts on PET emission images obtained using CT attenuation correction on PET-CT. Eur J Nucl Med Mol Imaging. 2003;30(4):603–6.
Pichler BJ, Kolb A, Nagele T, Schlemmer HP. PET/MRI: paving the way for the next generation of clinical multimodality imaging applications. J Nucl Med. 2010;51(3):333–6.
Tsoumpas C, Buerger C, King AP, Keereman V, Vandenberghe S, Schulz V, et al., editors. Simulation of dynamic PET data from real MR acquisitions. 2009 IEEE Nucl Sci Symp Conf Rec; Oct. 24–Nov. 1 2009.
Mackewn JE, Halsted P, Charles-Edwards G, Page R, Totman JJ, Sunassee K, et al. Performance evaluation of an MRI-compatible pre-clinical PET system using long optical fibers. IEEE Trans Nucl Sci. 2010;57(3):1052–62.
Mackewn JE, Charles-Edwards G, Totman JJ, Tsoumpas C, Halsted P, Somer EJ, et al., editors. A fiducial marker based technique for alignment of simultaneously acquired PET and MRI images. 2009 IEEE Nucl Sci Symp Conf Rec; Oct. 24–Nov. 1 2009.
Mackewn JE, Strul D, Hallett WA, Halsted P, Page RA, Keevil SF, et al. Design and development of an MR-compatible PET scanner for imaging small animals. IEEE Trans Nucl Sci. 2005;52(5):1376–80.
Thielemans K, Mustafovic S, Tsoumpas C. STIR: Software for Tomographic Image Reconstruction Release 2. 2006 IEEE Nucl Sci Symp Conf Rec; 2007. p. 2174–6.
Rueckert D, Sonoda LI, Hayes C, Hill DL, Leach MO, Hawkes DJ. Nonrigid registration using free-form deformations: application to breast MR images. IEEE Trans Med Imaging. 1999;18(8):712–21.
Loening A, Gambhir S. AMIDE: a free software tool for multimodality medical image analysis. Mol Imaging. 2003;2(3):131–7.
King AP, Rhode KS, Razavi RS, Schaeffter TR. An adaptive and predictive respiratory motion model for image-guided interventions: theory and first clinical application. IEEE Trans Med Imaging. 2009;28(12):2020–32.
Acknowledgments
We wish to thank the Guy’s and St. Thomas’ Hospital Medical Physics workshop for the construction of the rotating phantom. The work has been supported by the European Union under the 7th framework program (No. 201651) and the Division of Imaging Sciences and PET Imaging Centre, King’s College London.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Tsoumpas, C., Mackewn, J.E., Halsted, P. et al. Simultaneous PET–MR acquisition and MR-derived motion fields for correction of non-rigid motion in PET. Ann Nucl Med 24, 745–750 (2010). https://doi.org/10.1007/s12149-010-0418-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12149-010-0418-2