| Title |
Dental artifacts in the head and neck region: implications for Dixon-based attenuation correction in PET/MR
|
|---|---|
| Published in |
EJNMMI Physics, March 2015
|
| DOI | 10.1186/s40658-015-0112-5 |
| Pubmed ID | |
| Authors |
Claes N Ladefoged, Adam E Hansen, Sune H Keller, Barbara M Fischer, Jacob H Rasmussen, Ian Law, Andreas Kjær, Liselotte Højgaard, Francois Lauze, Thomas Beyer, Flemming L Andersen |
| Abstract |
In the absence of CT or traditional transmission sources in combined clinical positron emission tomography/magnetic resonance (PET/MR) systems, MR images are used for MR-based attenuation correction (MR-AC). The susceptibility effects due to metal implants challenge MR-AC in the neck region of patients with dental implants. The purpose of this study was to assess the frequency and magnitude of subsequent PET image distortions following MR-AC. A total of 148 PET/MR patients with clear visual signal voids on the attenuation map in the dental region were included in this study. Patients were injected with [(18)F]-FDG, [(11)C]-PiB, [(18)F]-FET, or [(64)Cu]-DOTATATE. The PET/MR data were acquired over a single-bed position of 25.8 cm covering the head and neck. MR-AC was based on either standard MR-ACDIXON or MR-ACINPAINTED where the susceptibility-induced signal voids were substituted with soft tissue information. Our inpainting algorithm delineates the outer contour of signal voids breaching the anatomical volume using the non-attenuation-corrected PET image and classifies the inner air regions based on an aligned template of likely dental artifact areas. The reconstructed PET images were evaluated visually and quantitatively using regions of interests in reference regions. The volume of the artifacts and the computed relative differences in mean and max standardized uptake value (SUV) between the two PET images are reported. The MR-based volume of the susceptibility-induced signal voids on the MR-AC attenuation maps was between 1.6 and 520.8 mL. The corresponding/resulting bias of the reconstructed tracer distribution was localized mainly in the area of the signal void. The mean and maximum SUVs averaged across all patients increased after inpainting by 52% (± 11%) and 28% (± 11%), respectively, in the corrected region. SUV underestimation decreased with the distance to the signal void and correlated with the volume of the susceptibility artifact on the MR-AC attenuation map. Metallic dental work may cause severe MR signal voids. The resulting PET/MR artifacts may exceed the actual volume of the dental fillings. The subsequent bias in PET is severe in regions in and near the signal voids and may affect the conspicuity of lesions in the mandibular region. |
X Demographics
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Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 1 | 100% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 1 | 100% |
Mendeley readers
The data shown below were compiled from readership statistics for 32 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Switzerland | 1 | 3% |
| Unknown | 31 | 97% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Researcher | 9 | 28% |
| Student > Ph. D. Student | 7 | 22% |
| Professor > Associate Professor | 3 | 9% |
| Student > Master | 2 | 6% |
| Student > Doctoral Student | 1 | 3% |
| Other | 4 | 13% |
| Unknown | 6 | 19% |
| Readers by discipline | Count | As % |
|---|---|---|
| Medicine and Dentistry | 7 | 22% |
| Physics and Astronomy | 7 | 22% |
| Computer Science | 2 | 6% |
| Engineering | 2 | 6% |
| Unspecified | 1 | 3% |
| Other | 5 | 16% |
| Unknown | 8 | 25% |
Attention Score in Context
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 27 October 2015.
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#15,349,419
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Outputs from EJNMMI Physics
#76
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#153,845
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Outputs of similar age from EJNMMI Physics
#1
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