Skip to main content

Advertisement

SpringerLink
Log in

PET/MR brain imaging: evaluation of clinical UTE-based attenuation correction

  • Original Article
  • Published:
European Journal of Nuclear Medicine and Molecular Imaging Aims and scope Submit manuscript

Abstract

One of the greatest challenges in PET/MR imaging is that of accurate MR-based attenuation correction (AC) of the acquired PET data, which must be solved if the PET/MR modality is to reach its full potential. The aim of this study was to investigate the performance of Siemens’ most recent version (VB20P) of MR-based AC of head PET data, by comparing it to CT-based AC.

Methods:18F-FDG PET data from seven lymphoma and twelve lung cancer patients examined with a Biograph mMR PET/MR system were reconstructed with both CT-based and MR-based AC, avoiding sources of error arising when comparing PET data from different systems. The resulting images were compared quantitatively by measuring changes in mean SUV in ten different brain regions in both hemispheres, as well as the brainstem. In addition, the attenuation maps (μ maps) were compared regarding volume and localization of cranial bone.

Results: The UTE μ maps clearly overestimate the amount of bone in the neck, while slightly underestimating the amount of bone in the cranium, and the localization of bone in the cranial region also differ from the CT μ maps. In air/tissue interfaces in the sinuses and ears, the MRAC method struggles to correctly classify the different tissues. The misclassification of tissue is most likely caused by a combination of artefacts and the insufficiency of the UTE method to accurately separate bone. Quantitatively, this results in a combination of overestimation (0.5–3.6 %) and underestimation (2.7–5.2 %) of PET activity throughout the brain, depending on the proximity to the inaccurate regions.

Conclusions: Our results indicate that the performance of the UTE method as implemented in VB20P is close to the theoretical maximum of such an MRAC method in the brain, while it does not perform satisfactorily in the neck or face/nasal area. Further improvement of the UTE MRAC or other available methods for more accurate segmentation of bone should be incorporated.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

Notes

  1. Personal communication with Dr. Peter Kreisler at Siemens.

References

  1. Bailey DL, Karp JS, Surti S. Physics and Instrumentation in PET. In: Bailey DL, Townsend DW, Valk PE, Maisey MN, editors. Positron Emission Tomography. London: Springer; 2005, pp. 13–39.

    Chapter  Google Scholar 

  2. Townsend DW. Basic Science of PET and PET/CT. In: Valk PE, Delbeke D, Bailey DL, Townsend DW, Maisey MN, editors. Positron Emission Tomography. London: Springer; 2006, pp. 1–16.

    Chapter  Google Scholar 

  3. Hofmann M, Pichler B, Schölkopf B, Beyer T. Towards quantitative PET/MRI: a review of MR-based attenuation correction techniques. Eur J Nucl Med Mol Imaging 2009;36:93–104.

    Article  Google Scholar 

  4. Kops E, Herzog H. Template based attenuation correction for PET in MR-PET scanners. IEEE Nucl Sci Symp Conf Rec 2008;2008:3786–9.

    Google Scholar 

  5. Schreibmann E, Nye JA, Schuster DM, Martin DR, Votaw J, Fox T. MR-based attenuation correction for hybrid PET-MR brain imaging systems using deformable image registration. Med Phys 2010;37:2101–9.

    Article  PubMed  Google Scholar 

  6. Zaidi H, Montandon ML, Slosman DO. Magnetic resonance imaging-guided attenuation and scatter corrections in three-dimensional brain positron emission tomography. Med Phys 2003;30:937–48.

    Article  PubMed  Google Scholar 

  7. Keereman V, Fierens Y, Broux T, De Deene Y, Lonneux M, Vandenberghe S. MRI-based attenuation correction for PET/MRI using ultrashort echo time sequences. J Nucl Med 2010;51:812–8.

    Article  PubMed  Google Scholar 

  8. Aznar MC, Sersar R, Saabye J, et al. Whole-body PET/MRI: the effect of bone attenuation during MR-based attenuation correction in oncology imaging. Eur J Radiol 2014;83:1177–83.

    Article  CAS  PubMed  Google Scholar 

  9. Samarin A, Burger C, Wollenweber SD, et al. PET/MR imaging of bone lesions: implications for PET quantification from imperfect attenuation correction. Eur J Nucl Med Mol Imaging 2012;39:1154–60.

    Article  PubMed  Google Scholar 

  10. Bezrukov I, Mantlik F, Schmidt H, Schölkopf B, Pichler BJ, MR-Based PET. Attenuation correction for PET/MR imaging. Semin Nucl Med 2013;43:45–59.

    Article  PubMed  Google Scholar 

  11. Akbarzadeh A, Ay MR, Ahmadian A, Riahi Alam N, Zaidi H. MRI-guided attenuation correction in whole-body PET/MR: assessment of the effect of bone attenuation. Ann Nucl Med 2013;27:152–62.

    Article  CAS  PubMed  Google Scholar 

  12. Andersen FL, Ladefoged CN, Beyer T, et al. Combined PET/MR imaging in neurology: MR-based attenuation correction implies a strong spatial bias when ignoring bone. Neuroimage 2014;84:206–16.

    Article  PubMed  Google Scholar 

  13. Robson MD, Gatehouse PD, Bydder M, Bydder GM. Magnetic resonance: an introduction to ultrashort TE (UTE) imaging. J Comput Assist Tomogr 2003;27:825–46.

    Article  PubMed  Google Scholar 

  14. Berker Y, Franke J, Salomon A, et al. 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 2012; 53:796– 804.

    Article  PubMed  Google Scholar 

  15. Dickson JC, O’Meara C, Barnes A. A comparison of CT- and MR-based attenuation correction in neurological PET. Eur J Nucl Med Mol Imaging 2014;51:1–14.

    Google Scholar 

  16. Choi H, Cheon GJ, Kim HJ, et al. Segmentation-based MR attenuation correction including bones also affects quantitation in brain studies: an initial result of 18F-FP-CIT PET/MR for patients with Parkinsonism. J Nucl Med 2014;55:1617– 22.

    Article  CAS  PubMed  Google Scholar 

  17. Block KT, Uecker M. Simple method for adaptive gradient-delay compensation in radial MRI. Proc Int Soc Magn Reson Med 2011:2816.

  18. Klein S, Staring M, Murphy K, Viergever MA, Pluim JPW. elastix: A toolbox for intensity-based medical image registration. IEEE Trans Med Imaging 2010;29:196–205.

    Article  PubMed  Google Scholar 

  19. Delso G, Carl M, Wiesinger F, et al. Anatomic evaluation of 3-dimensional ultrashort-echo-time bone maps for PET/MR attenuation correction. J Nucl Med 2014;55:780–5.

    Article  PubMed  Google Scholar 

  20. Navalpakkam BK, Braun H, Kuwert T, Quick HH. Magnetic resonance-based attenuation correction for PET/MR hybrid imaging using continuous valued attenuation maps. Invest Radiol 2013;48:323–32.

    Article  PubMed  Google Scholar 

  21. Dice LR. Measures of the amount of ecologic association between species. Ecology 1945;26:297–302.

    Article  Google Scholar 

  22. Cheetham AH, Hazel JE. Binary (presence-absence) similarity coefficients. J Paleontol 1969;43:1130–6.

    Google Scholar 

  23. Aitken AP, Giese D, Tsoumpas C, et al. Improved UTE-based attenuation correction for cranial PET-MR using dynamic magnetic field monitoring. Med Phys 2014;41:1–13.

    Article  Google Scholar 

  24. Oliveira RCG, Leles CR, Normanha LM, Lindh C, Ribeiro-Rotta RF. Assessments of trabecular bone density at implant sites on CT images. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;105:231–8.

    Article  PubMed  Google Scholar 

  25. Catana C, Kouwe A, Benner T, et al. Toward implementing an MRI-based PET attenuation-correction method for neurologic studies on the MR-PET brain prototype. J Nucl Med 2010;51:1431–8.

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  26. Velasquez LM, Boellaard R, Kollia G, et al. Repeatability of 18F-FDG PET in a multicenter phase i study of patients with advanced gastrointestinal malignancies. J Nucl Med 2009;50:1646–54.

    Article  CAS  PubMed  Google Scholar 

  27. Weber W, Ziegler S, Thödtmann R, Hanauske A, Schwaiger M. Reproducibility of metabolic measurements in malignant tumors using FDG PET. J Nucl Med 1999;40:1771–7.

    CAS  PubMed  Google Scholar 

Download references

Acknowledgements

This project has received technical support from Siemens; special thanks to Matthias Fenchel, Dieter Manthey and Björn Jakoby. The authors would also like to thank Ilja Bezrukov, Holger Schmidt, Thomas Keil, Per Arvid Steen, Kristian Wibe-Eidissen, and Jian Xu for invaluable help with acquisition and analysis of data.

Author information

Authors and Affiliations

  1. Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), 7489, Trondheim, Norway

    Lars Birger Aasheim & Live Eikenes

  2. Clinic of Radiology and Nuclear Medicine, St. Olavs University Hospital, Trondheim, Norway

    Lars Birger Aasheim, Anna Karlberg & Pål Erik Goa

  3. Department of Physics, NTNU, Trondheim, Norway

    Pål Erik Goa

  4. Department of Neuroscience, NTNU, Trondheim, Norway

    Asta Håberg

  5. Department of Thoracic Medicine, St. Olavs University Hospital, Trondheim, Norway

    Sveinung Sørhaug

  6. Department of Oncology, St. Olavs University Hospital, Trondheim, Norway

    Unn-Merete Fagerli

  7. Department of Cancer Research and Molecular Medicine, NTNU, Trondheim, Norway

    Unn-Merete Fagerli

  8. Department of Medical Imaging, St. Olavs University Hospital, Trondheim, Norway

    Asta Håberg

Authors
  1. Lars Birger Aasheim
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Anna Karlberg
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Pål Erik Goa
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Asta Håberg
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Sveinung Sørhaug
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Unn-Merete Fagerli
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Live Eikenes
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Live Eikenes.

Additional information

Conflict of interest

The study was performed with technical support from Siemens employees

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Aasheim, L.B., Karlberg, A., Goa, P.E. et al. PET/MR brain imaging: evaluation of clinical UTE-based attenuation correction. Eur J Nucl Med Mol Imaging 42, 1439–1446 (2015). https://doi.org/10.1007/s00259-015-3060-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00259-015-3060-3

Keywords

Search

Navigation