Attenuation correction synthesis for hybrid PET-MR scanners: validation for brain study applications
© Burgos et al; licensee Springer 2014
Published: 29 July 2014
In this work, we further validate a CT and attenuation map (μ-map) synthesis algorithm .
The CT synthesis method relies on a pre-acquired set of aligned MRI/CT pairs from multiple subjects. Each MRI from the database is non-rigidly registered to the target MRI. The CTs in the database are then mapped using the same transformation to the target MRI. A local image similarity measure between the target MRI and the set of registered MRIs is used as a surrogate of the underlying morphological similarity. Finally, the synthetic CT is generated using a voxel-wise weighting scheme, and converted to linear attenuation coefficients by a piecewise linear transformation.
Following the proposed method, a pseudo CT (pCT) was generated using only the MRI of the subject and compared to the ground truth CT, validating the accuracy of the CT synthesis. A PET image (PETpCT) was then reconstructed with an off-line version of the Siemens Healthcare reconstruction software using the pCT μ-map, and compared with the gold standard PET reconstructed using the CT μ-map.
Average and SD of the mean absolute residual and mean residual between the ground truth CT and both the pseudo CT, best-atlas CT (baCT) and UTE CT (left column); average and SD of the relative MAR and relative MR between the gold standard CT PET and both the pseudo CT, best-atlas CT and UTE PETs (right column).
CT (HU) - Head
PET (%) - Brain
This work was supported by an IMPACT studentship funded jointly by Siemens and the UCL FES. The Dementia Research Centre is an Alzheimer’s Research UK Co-ordinating Centre and has also received equip- ment funded by Alzheimer’s Research UK and Brain Research Trust. Funding was received from the EPSRC (EP/H046410/1, EP/J020990/1, EP/K005278), the MRC (MR/J01107X/1), the EU-FP7 project VPH- DARE@IT (FP7-ICT-2011-9-601055) and the NIHR Biomedical Research Unit (Dementia) at UCL. This work was also supported by researchers at the NIHR UCLH BRC (including the High Impact Initiative).
- Burgos N, Cardoso M, Modat M, Pedemonte S, Dickson J, Barnes A, Duncan JS, Atkinson D, Arridge SR, Hutton BF, Ourselin S: Attenuation Correction Synthesis for Hybrid PET-MR Scanners. MICCAI 2013, 147–154.Google Scholar
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