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Accurate PET/MR Quantification Using Time of Flight MLAA Image Reconstruction

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Abstract

Purpose

Quantification of positron emission tomography/magnetic resonance imaging (PET/MRI) studies is hampered by inaccurate MR-based attenuation correction (MR-AC). To date, most studies on MR-AC have been performed using PET/MR systems without time of flight (TOF). Maximum likelihood reconstruction of attenuation and activity (MLAA), however, has the potential to improve MR-AC by exploiting TOF. The purpose of this study is to assess the impact of MR-AC on PET image quantification for TOF-PET/MR systems and to evaluate PET accuracy when using TOF in combination with MLAA (TOF-MLAA).

Procedures

Simulations were designed to evaluate (1) the impact of MR-AC on PET quantification for different TOF windows (667, 500, 333 and 167 ps) and (2) use of TOF-MLAA for improving PET quantification. TOF-ordered subset expectation maximisation (OSEM) and TOF-MLAA reconstructions using MR-AC were compared with those obtained using TOF-OSEM with computed tomography-based AC (CT-AC).

Results

OSEM reconstructions without TOF showed a negative MR-AC-induced bias of −50 % in the bone. TOF-OSEM was able to reduce this bias down to −15 %, with more accurate results for better TOF. TOF-MLAA was able to reduce the bias to within 5 % but at the cost of a ∼40 % increase in image variance.

Conclusions

TOF-MLAA can improve quantitative PET accuracy of PET/MR studies. Further improvements are anticipated with improving TOF performance.

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References

  1. Delso G, Furst S, Jakoby B et al (2011) Performance measurements of the Siemens mMR integrated whole-body PET/MR scanner. J Nucl Med 52:1914–1922

    Article  PubMed  Google Scholar 

  2. Zaidi H, Ojha N, Morich M et al (2011) Design and performance evaluation of a whole-body Ingenuity TF PET-MRI system. Phys Med Biol 56:3091–3106

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  3. Beyer T, Pichler B (2009) A decade of combined imaging: from a PET attached to a CT to a PET inside an MR. Eur J Nucl Med Mol Imaging 36(Suppl 1):S1–S2

    Article  PubMed  Google Scholar 

  4. Herzog H, van den Hoff J (2012) Combined PET/MR systems: an overview and comparison of currently available options. Q J Nucl Med Mol Imaging 56:247–267

    CAS  PubMed  Google Scholar 

  5. Herzog H (2012) PET/MRI: challenges, solutions and perspectives. Z Med Phys 22:281–298

    Article  PubMed  Google Scholar 

  6. Maniawski P (2011) PET/MR: the molecular imaging dream team. Nucl Med Rev Cent East Eur 14:47–50

    Article  PubMed  Google Scholar 

  7. Pichler BJ, Kolb A, Nagele T, Schlemmer HP (2010) PET/MRI: paving the way for the next generation of clinical multimodality imaging applications. J Nucl Med 51:333–336

    Article  PubMed  Google Scholar 

  8. Wehrl HF, Sauter AW, Judenhofer MS, Pichler BJ (2010) Combined PET/MR imaging–technology and applications. Technol Cancer Res Treat 9:5–20

    CAS  PubMed  Google Scholar 

  9. Pichler BJ, Judenhofer MS, Wehrl HF (2008) PET/MRI hybrid imaging: devices and initial results. Eur Radiol 18:1077–1086

    Article  PubMed  Google Scholar 

  10. Delso G, Martinez-Moller A, Bundschuh RA et al (2010) Evaluation of the attenuation properties of MR equipment for its use in a whole-body PET/MR scanner. Phys Med Biol 55:4361–4374

    Article  CAS  PubMed  Google Scholar 

  11. Delso G, Martinez-Moller A, Bundschuh RA et al (2010) The effect of limited MR field of view in MR/PET attenuation correction. Med Phys 37:2804–2812

    Article  PubMed  Google Scholar 

  12. Hofmann M, Pichler B, Scholkopf B, Beyer T (2009) Towards quantitative PET/MRI: a review of MR-based attenuation correction techniques. Eur J Nucl Med Mol Imaging 36(Suppl 1):S93–S104

    Article  PubMed  Google Scholar 

  13. Keller SH, Holm S, Hansen AE et al (2013) Image artifacts from MR-based attenuation correction in clinical, whole-body PET/MRI. Magma 26:173–181

    Article  PubMed  Google Scholar 

  14. Andersen FL, Ladefoged CN, Beyer T et al (2013) Combined PET/MR imaging in neurology: MR-based attenuation correction implies a strong spatial bias when ignoring bone. Neuroimage 84:206–216

    Article  PubMed  Google Scholar 

  15. Berker Y, Franke J, Salomon A et al (2012) MRI-based attenuation correction for hybrid PET/MRI systems: a 4-class tissue segmentation technique using a combined ultrashort-echo-time/Dixon MRI sequence. J Nucl Med 53:796–804

    Article  PubMed  Google Scholar 

  16. Schulz V, Torres-Espallardo I, Renisch S et al (2011) Automatic, three-segment, MR-based attenuation correction for whole-body PET/MR data. Eur J Nucl Med Mol Imaging 38:138–152

    Article  CAS  PubMed  Google Scholar 

  17. Paulus DH, Braun H, Aklan B, Quick HH (2012) Simultaneous PET/MR imaging: MR-based attenuation correction of local radiofrequency surface coils. Med Phys 39:4306–4315

    Article  PubMed  Google Scholar 

  18. Wollenweber SD, Delso G, Deller T et al (2013) Characterization of the impact to PET quantification and image quality of an anterior array surface coil for PET/MR imaging. Magma (Epub ahead of print)

  19. Hofmann M, Bezrukov I, Mantlik F et al (2011) MRI-based attenuation correction for whole-body PET/MRI: quantitative evaluation of segmentation- and atlas-based methods. J Nucl Med 52:1392–1399

    Article  PubMed  Google Scholar 

  20. Hofmann M, Steinke F, Scheel V et al (2008) MRI-based attenuation correction for PET/MRI: a novel approach combining pattern recognition and atlas registration. J Nucl Med 49:1875–1883

    Article  PubMed  Google Scholar 

  21. Keereman V, Fierens Y, Broux T et al (2010) MRI-based attenuation correction for PET/MRI using ultrashort echo time sequences. J Nucl Med 51:812–818

    Article  PubMed  Google Scholar 

  22. Rezaei A, Defrise M, Bal G et al (2012) Simultaneous reconstruction of activity and attenuation in time-of-flight PET. IEEE Trans Med Imaging 31:2224–2233

    Article  PubMed  Google Scholar 

  23. Nuyts J, Bal G, Kehren F et al (2013) Completion of a truncated attenuation image from the attenuated PET emission data. IEEE Trans Med Imaging 32:237–246

    Article  PubMed  Google Scholar 

  24. Nuyts J, Dupont P, Stroobants S et al (1999) Simultaneous maximum a posteriori reconstruction of attenuation and activity distributions from emission sinograms. IEEE Trans Med Imaging 18:393–403

    Article  CAS  PubMed  Google Scholar 

  25. Salomon A, Goedicke A, Schweizer B et al (2011) Simultaneous reconstruction of activity and attenuation for PET/MR. IEEE Trans Med Imaging 30:804–813

    Article  PubMed  Google Scholar 

  26. Defrise M, Rezaei A, Nuyts J (2012) Time-of-flight PET data determine the attenuation sinogram up to a constant. Phys Med Biol 57:885–899

    Article  PubMed  Google Scholar 

  27. Boellaard R, Krak NC, Hoekstra OS, Lammertsma AA (2004) Effects of noise, image resolution, and ROI definition on the accuracy of standard uptake values: a simulation study. J Nucl Med 45:1519–1527

    PubMed  Google Scholar 

  28. Cheebsumon P, Yaqub M, van Velden FH et al (2011) Impact of [18F]FDG PET imaging parameters on automatic tumour delineation: need for improved tumour delineation methodology. Eur J Nucl Med Mol Imaging 38:2136–2144

    Article  PubMed Central  PubMed  Google Scholar 

  29. Wagenknecht G, Kaiser HJ, Mottaghy FM, Herzog H (2013) MRI for attenuation correction in PET: methods and challenges. Magma 26:99–113

    Article  PubMed Central  PubMed  Google Scholar 

  30. Bezrukov I, Mantlik F, Schmidt H et al (2013) MR-based PET attenuation correction for PET/MR imaging. Semin Nucl Med 43:45–59

    Article  PubMed  Google Scholar 

  31. Martinez-Moller A, Nekolla SG (2012) Attenuation correction for PET/MR: problems, novel approaches and practical solutions. Z Med Phys 22:299–310

    Article  PubMed  Google Scholar 

  32. Eiber M, Martinez-Moller A, Souvatzoglou M et al (2011) Value of a Dixon-based MR/PET attenuation correction sequence for the localization and evaluation of PET-positive lesions. Eur J Nucl Med Mol Imaging 38:1691–1701

    Article  PubMed  Google Scholar 

  33. Beyer T, Weigert M, Quick HH et al (2008) MR-based attenuation correction for torso-PET/MR imaging: pitfalls in mapping MR to CT data. Eur J Nucl Med Mol Imaging 35:1142–1146

    Article  PubMed  Google Scholar 

  34. Akbarzadeh A, Ay MR, Ahmadian A et al (2013) MRI-guided attenuation correction in whole-body PET/MR: assessment of the effect of bone attenuation. Ann Nucl Med 27:152–162

    Article  CAS  PubMed  Google Scholar 

  35. Catana C, van der Kouwe A, Benner T et al (2010) Toward implementing an MRI-based PET attenuation-correction method for neurologic studies on the MR-PET brain prototype. J Nucl Med 51:1431–1438

    Article  CAS  PubMed Central  PubMed  Google Scholar 

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Conflict of Interest

The authors have a research collaboration with Philips Healthcare.

Author information

Authors and Affiliations

  1. Department of Radiology and Nuclear Medicine, VU University Medical Centre, Amsterdam, The Netherlands

    R. Boellaard, O. S. Hoekstra & A. A. Lammertsma

  2. Department of Physics and Medical Technology, VU University Medical Centre, Amsterdam, The Netherlands

    M. B. M. Hofman

Authors
  1. R. Boellaard
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  2. M. B. M. Hofman
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  3. O. S. Hoekstra
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  4. A. A. Lammertsma
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Corresponding author

Correspondence to R. Boellaard.

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Boellaard, R., Hofman, M.B.M., Hoekstra, O.S. et al. Accurate PET/MR Quantification Using Time of Flight MLAA Image Reconstruction. Mol Imaging Biol 16, 469–477 (2014). https://doi.org/10.1007/s11307-013-0716-x

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