Magnetic Resonance–Based Attenuation Correction for PET/MR Hybrid Imaging Using Continuous Valued Attenuation Maps

  title={Magnetic Resonance–Based Attenuation Correction for PET/MR Hybrid Imaging Using Continuous Valued Attenuation Maps},
  author={Bharath K. Navalpakkam and Harald Braun and Torsten Kuwert and Harald Quick},
  journal={Investigative Radiology},
ObjectivesAttenuation correction of positron emission tomographic (PET) data is critical in providing accurate and quantitative PET volumes. Deriving an attenuation map (&mgr;-map) from magnetic resonance (MR) volumes is a challenge in PET/MR hybrid imaging. The difficulty lies in differentiating cortical bone from air from standard MR sequences because both these classes yield little to no MR signal and thus shows no distinguishable information. The objective of this contribution is 2-fold: (1… 
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Techniques to improve carotid vascular PET/MR quantification by adding a bone tissue compartment to MRAC maps and deriving continuous Dixon-based MRAC (MRACCD) maps are demonstrated.
Tissue Probability-Based Attenuation Correction for Brain PET/MR by Using SPM8
A tissue-probability based attenuation correction (TPB-AC) is proposed, which employs the commonly available neurological toolbox SPM8 to derive a subject-specific MR-based μ-map by segmentation of T1-weighted MR images, showing improvement of visual quality and quantitative accuracy of positron emission tomography (PET) images when TPB- AC μ- map is used in PET/MR image reconstruction.
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Automatic, three-segment, MR-based attenuation correction for whole-body PET/MR data
A fully automated approach that uses a dedicated T1-weighted MR sequence in combination with a customized image processing technique to derive attenuation maps for whole-body PET and offers similar correction accuracy as offered by segmented CT.
MRI-Based Attenuation Correction for Hybrid PET/MRI Systems: A 4-Class Tissue Segmentation Technique Using a Combined Ultrashort-Echo-Time/Dixon MRI Sequence
The UTE triple-echo (UTILE) MRI sequence enables the generation of MRI-based 4-class μ-maps without anatomic priors, yielding results more similar to CT-based results than can be obtained with 3-class segmentation only.
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A combination of local pattern recognition and atlas registration is used to predict pseudo-CT images from a given MR image, which allows reliable MRI-based attenuation correction for human brain scans and enables PET quantification with a mean error of 3.2%.
Quantitative accuracy of attenuation correction in the Philips Ingenuity TF whole-body PET/MR system: a direct comparison with transmission-based attenuation correction
The MR-based attenuation correction implemented on the Philips Ingenuity PET/MR provides reasonable quantitative accuracy, and deviations from TRAC-based results are small, but due to interindividual variability of the segmentation quality, deviations of more than 20 %  can occur.
Image artifacts from MR-based attenuation correction in clinical, whole-body PET/MRI
  • S. KellerS. Holm T. Beyer
  • Medicine, Physics
    Magnetic Resonance Materials in Physics, Biology and Medicine
  • 2012
A clinical adoption of integrated PET/MRI should entail the joint image display and interpretation of MR data, MR-based attenuation maps and uncorrected plus attenuation-corrected PET images in order to recognize potential pitfalls from MR-AC and to ensure clinically accurate image interpretation.
Toward Implementing an MRI-Based PET Attenuation-Correction Method for Neurologic Studies on the MR-PET Brain Prototype
The segmented CT AC method was established as the silver standard for the segmented MRI-based AC method and could be used for quantitative neurologic MR-PET studies.
Diffusion Tensor Imaging in a Human PET/MR Hybrid System
Diffusion tensor imaging may be combined with simultaneous PET data acquisition, offering additional important morphologic and functional information for treatment planning in patients with brain tumors.
Attenuation correction for a combined 3D PET/CT scanner.
The proof of principle of CT-based attenuation correction of 3D positron emission tomography (PET) data is demonstrated by using scans of bone and soft tissue equivalent phantoms and scans of humans to conclude that using CT information is a feasible way to obtain attenuation Correction factors for 3D PET.
The effect of errors in segmented attenuation maps on PET quantification.
When using a segmented attenuation map, at least five different tissue types should be considered: cortical bone, spongeous bone, soft tissue, lung, and air, and the interpatient variability of lung attenuation coefficients should be taken into account.
Comparison of lesion detection and quantitation of tracer uptake between PET from a simultaneously acquiring whole-body PET/MR hybrid scanner and PET from PET/CT
PET/MR showed equivalent performance in terms of qualitative lesion detection to PET/CT and quantitation of tracer uptake, and a more detailed study of the quantitative accuracy of PETMR and the factors governing it is needed to ultimately assess its accuracy in measuring tissue tracer concentrations.