Multi-contrast attenuation map synthesis for PET/MR scanners: assessment on FDG and Florbetapir PET tracers

Ninon Burgos; M. Jorge Cardoso; Kris Thielemans; Marc Modat; John Dickson; Jonathan M. Schott; David Atkinson; Simon R. Arridge; Brian F. Hutton; Sébastien Ourselin

doi:10.1007/s00259-015-3082-x

Multi-contrast attenuation map synthesis for PET/MR scanners: assessment on FDG and Florbetapir PET tracers

Ninon Burgos^*, M. Jorge Cardoso, Kris Thielemans, Marc Modat, John Dickson, Jonathan M. Schott, David Atkinson, Simon R. Arridge, Brian F. Hutton, Sébastien Ourselin

^*Corresponding author for this work

Imaging and Biomedical Engineering

Research output: Contribution to journal › Article › peer-review

34 Citations (Scopus)

Abstract

Positron Emission Tomography/Magnetic Resonance Imaging (PET/MR) scanners are expected to offer a new range of clinical applications. Attenuation correction is an essential requirement for quantification of PET data but MRI images do not directly provide a patient-specific attenuation map. Methods We further validate and extend a Computed Tomography (CT) and attenuation map (μ-map) synthesis method based on pre-acquired MRI-CT image pairs. The validation consists of comparing the CT images synthesised with the proposed method to the original CT images. PET images were acquired using two different tracers (¹⁸F-FDG and ¹⁸F-florbetapir). They were then reconstructed and corrected for attenuation using the synthetic μ-maps and compared to the reference PET images corrected with the CT-based μ-maps. During the validation, we observed that the CT synthesis was inaccurate in areas such as the neck and the cerebellum, and propose a refinement to mitigate these problems, as well as an extension of the method to multi-contrast MRI data. Results With the improvements proposed, a significant enhancement in CT synthesis, which results in a reduced absolute error and a decrease in the bias when reconstructing PET images, was observed. For both tracers, on average, the absolute difference between the reference PET images and the PET images corrected with the proposed method was less than 2%, with a bias inferior to 1%. Conclusion With the proposed method, attenuation information can be accurately derived from MRI images by synthesising CT using routine anatomical sequences. MRI sequences, or combination of sequences, can be used to synthesise CT images, as long as they provide sufficient anatomical information.

Original language	English
Pages (from-to)	1447-1458
Number of pages	12
Journal	European Journal of Nuclear Medicine and Molecular Imaging
Volume	42
Issue number	9
DOIs	https://doi.org/10.1007/s00259-015-3082-x
Publication status	Published - 24 Aug 2015

Keywords

Attenuation correction
Image synthesis
PET/MR

Access to Document

10.1007/s00259-015-3082-x

Cite this

Burgos, N., Cardoso, M. J., Thielemans, K., Modat, M., Dickson, J., Schott, J. M., Atkinson, D., Arridge, S. R., Hutton, B. F., & Ourselin, S. (2015). Multi-contrast attenuation map synthesis for PET/MR scanners: assessment on FDG and Florbetapir PET tracers. European Journal of Nuclear Medicine and Molecular Imaging, 42(9), 1447-1458. https://doi.org/10.1007/s00259-015-3082-x

@article{b135b2d9b63c4fe8bd3615002f98c38c,

title = "Multi-contrast attenuation map synthesis for PET/MR scanners: assessment on FDG and Florbetapir PET tracers",

abstract = "Positron Emission Tomography/Magnetic Resonance Imaging (PET/MR) scanners are expected to offer a new range of clinical applications. Attenuation correction is an essential requirement for quantification of PET data but MRI images do not directly provide a patient-specific attenuation map. Methods We further validate and extend a Computed Tomography (CT) and attenuation map (μ-map) synthesis method based on pre-acquired MRI-CT image pairs. The validation consists of comparing the CT images synthesised with the proposed method to the original CT images. PET images were acquired using two different tracers (18F-FDG and 18F-florbetapir). They were then reconstructed and corrected for attenuation using the synthetic μ-maps and compared to the reference PET images corrected with the CT-based μ-maps. During the validation, we observed that the CT synthesis was inaccurate in areas such as the neck and the cerebellum, and propose a refinement to mitigate these problems, as well as an extension of the method to multi-contrast MRI data. Results With the improvements proposed, a significant enhancement in CT synthesis, which results in a reduced absolute error and a decrease in the bias when reconstructing PET images, was observed. For both tracers, on average, the absolute difference between the reference PET images and the PET images corrected with the proposed method was less than 2%, with a bias inferior to 1%. Conclusion With the proposed method, attenuation information can be accurately derived from MRI images by synthesising CT using routine anatomical sequences. MRI sequences, or combination of sequences, can be used to synthesise CT images, as long as they provide sufficient anatomical information.",

keywords = "Attenuation correction, Image synthesis, PET/MR",

author = "Ninon Burgos and Cardoso, {M. Jorge} and Kris Thielemans and Marc Modat and John Dickson and Schott, {Jonathan M.} and David Atkinson and Arridge, {Simon R.} and Hutton, {Brian F.} and S{\'e}bastien Ourselin",

year = "2015",

month = aug,

day = "24",

doi = "10.1007/s00259-015-3082-x",

language = "English",

volume = "42",

pages = "1447--1458",

journal = "European Journal of Nuclear Medicine and Molecular Imaging",

issn = "1619-7070",

publisher = "SPRINGER",

number = "9",

}

Burgos, N, Cardoso, MJ, Thielemans, K, Modat, M, Dickson, J, Schott, JM, Atkinson, D, Arridge, SR, Hutton, BF & Ourselin, S 2015, 'Multi-contrast attenuation map synthesis for PET/MR scanners: assessment on FDG and Florbetapir PET tracers', European Journal of Nuclear Medicine and Molecular Imaging, vol. 42, no. 9, pp. 1447-1458. https://doi.org/10.1007/s00259-015-3082-x

TY - JOUR

T1 - Multi-contrast attenuation map synthesis for PET/MR scanners

T2 - assessment on FDG and Florbetapir PET tracers

AU - Burgos, Ninon

AU - Cardoso, M. Jorge

AU - Thielemans, Kris

AU - Modat, Marc

AU - Dickson, John

AU - Schott, Jonathan M.

AU - Atkinson, David

AU - Arridge, Simon R.

AU - Hutton, Brian F.

AU - Ourselin, Sébastien

PY - 2015/8/24

Y1 - 2015/8/24

N2 - Positron Emission Tomography/Magnetic Resonance Imaging (PET/MR) scanners are expected to offer a new range of clinical applications. Attenuation correction is an essential requirement for quantification of PET data but MRI images do not directly provide a patient-specific attenuation map. Methods We further validate and extend a Computed Tomography (CT) and attenuation map (μ-map) synthesis method based on pre-acquired MRI-CT image pairs. The validation consists of comparing the CT images synthesised with the proposed method to the original CT images. PET images were acquired using two different tracers (18F-FDG and 18F-florbetapir). They were then reconstructed and corrected for attenuation using the synthetic μ-maps and compared to the reference PET images corrected with the CT-based μ-maps. During the validation, we observed that the CT synthesis was inaccurate in areas such as the neck and the cerebellum, and propose a refinement to mitigate these problems, as well as an extension of the method to multi-contrast MRI data. Results With the improvements proposed, a significant enhancement in CT synthesis, which results in a reduced absolute error and a decrease in the bias when reconstructing PET images, was observed. For both tracers, on average, the absolute difference between the reference PET images and the PET images corrected with the proposed method was less than 2%, with a bias inferior to 1%. Conclusion With the proposed method, attenuation information can be accurately derived from MRI images by synthesising CT using routine anatomical sequences. MRI sequences, or combination of sequences, can be used to synthesise CT images, as long as they provide sufficient anatomical information.

AB - Positron Emission Tomography/Magnetic Resonance Imaging (PET/MR) scanners are expected to offer a new range of clinical applications. Attenuation correction is an essential requirement for quantification of PET data but MRI images do not directly provide a patient-specific attenuation map. Methods We further validate and extend a Computed Tomography (CT) and attenuation map (μ-map) synthesis method based on pre-acquired MRI-CT image pairs. The validation consists of comparing the CT images synthesised with the proposed method to the original CT images. PET images were acquired using two different tracers (18F-FDG and 18F-florbetapir). They were then reconstructed and corrected for attenuation using the synthetic μ-maps and compared to the reference PET images corrected with the CT-based μ-maps. During the validation, we observed that the CT synthesis was inaccurate in areas such as the neck and the cerebellum, and propose a refinement to mitigate these problems, as well as an extension of the method to multi-contrast MRI data. Results With the improvements proposed, a significant enhancement in CT synthesis, which results in a reduced absolute error and a decrease in the bias when reconstructing PET images, was observed. For both tracers, on average, the absolute difference between the reference PET images and the PET images corrected with the proposed method was less than 2%, with a bias inferior to 1%. Conclusion With the proposed method, attenuation information can be accurately derived from MRI images by synthesising CT using routine anatomical sequences. MRI sequences, or combination of sequences, can be used to synthesise CT images, as long as they provide sufficient anatomical information.

KW - Attenuation correction

KW - Image synthesis

KW - PET/MR

UR - http://www.scopus.com/inward/record.url?scp=84937815980&partnerID=8YFLogxK

U2 - 10.1007/s00259-015-3082-x

DO - 10.1007/s00259-015-3082-x

M3 - Article

C2 - 26105119

AN - SCOPUS:84937815980

SN - 1619-7070

VL - 42

SP - 1447

EP - 1458

JO - European Journal of Nuclear Medicine and Molecular Imaging

JF - European Journal of Nuclear Medicine and Molecular Imaging

IS - 9

ER -

Multi-contrast attenuation map synthesis for PET/MR scanners: assessment on FDG and Florbetapir PET tracers

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this