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Automated movement correction for dynamic PET/CT images: evaluation with phantom and patient data.

Ye H, Wong KP, Wardak M, Dahlbom M, Kepe V, Barrio JR, Nelson LD, Small GW, Huang SC - PLoS ONE (2014)

Bottom Line: Image artifacts were significantly diminished after MC.There were significant differences (P<0.05) in the FDDNP DVR and FDG Ki values in the parietal and temporal regions after MC.In conclusion, MC applied to dynamic brain FDDNP and FDG PET/CT scans could improve the qualitative and quantitative aspects of images of both tracers.

View Article: PubMed Central - PubMed

Affiliation: Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America.

ABSTRACT
Head movement during a dynamic brain PET/CT imaging results in mismatch between CT and dynamic PET images. It can cause artifacts in CT-based attenuation corrected PET images, thus affecting both the qualitative and quantitative aspects of the dynamic PET images and the derived parametric images. In this study, we developed an automated retrospective image-based movement correction (MC) procedure. The MC method first registered the CT image to each dynamic PET frames, then re-reconstructed the PET frames with CT-based attenuation correction, and finally re-aligned all the PET frames to the same position. We evaluated the MC method's performance on the Hoffman phantom and dynamic FDDNP and FDG PET/CT images of patients with neurodegenerative disease or with poor compliance. Dynamic FDDNP PET/CT images (65 min) were obtained from 12 patients and dynamic FDG PET/CT images (60 min) were obtained from 6 patients. Logan analysis with cerebellum as the reference region was used to generate regional distribution volume ratio (DVR) for FDDNP scan before and after MC. For FDG studies, the image derived input function was used to generate parametric image of FDG uptake constant (Ki) before and after MC. Phantom study showed high accuracy of registration between PET and CT and improved PET images after MC. In patient study, head movement was observed in all subjects, especially in late PET frames with an average displacement of 6.92 mm. The z-direction translation (average maximum = 5.32 mm) and x-axis rotation (average maximum = 5.19 degrees) occurred most frequently. Image artifacts were significantly diminished after MC. There were significant differences (P<0.05) in the FDDNP DVR and FDG Ki values in the parietal and temporal regions after MC. In conclusion, MC applied to dynamic brain FDDNP and FDG PET/CT scans could improve the qualitative and quantitative aspects of images of both tracers.

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Movement correction for PET/CT misalignment induced by head translation and rotation in FDG phantom study.
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pone-0103745-g006: Movement correction for PET/CT misalignment induced by head translation and rotation in FDG phantom study.

Mentions: Result of the application of the automated MC procedure to the second phantom study is shown in Fig. 6 that demonstrated the procedure's ability to correct misalignment induced by head rotation besides translation. Co-registration to the reference frame (without CT MC) (column 1) only reduced the attenuation artifact (column 3). Mean left-right asymmetry decreased significantly (P<0.05) from 46.8% to 6.5% after MC (column 4).


Automated movement correction for dynamic PET/CT images: evaluation with phantom and patient data.

Ye H, Wong KP, Wardak M, Dahlbom M, Kepe V, Barrio JR, Nelson LD, Small GW, Huang SC - PLoS ONE (2014)

Movement correction for PET/CT misalignment induced by head translation and rotation in FDG phantom study.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4128781&req=5

pone-0103745-g006: Movement correction for PET/CT misalignment induced by head translation and rotation in FDG phantom study.
Mentions: Result of the application of the automated MC procedure to the second phantom study is shown in Fig. 6 that demonstrated the procedure's ability to correct misalignment induced by head rotation besides translation. Co-registration to the reference frame (without CT MC) (column 1) only reduced the attenuation artifact (column 3). Mean left-right asymmetry decreased significantly (P<0.05) from 46.8% to 6.5% after MC (column 4).

Bottom Line: Image artifacts were significantly diminished after MC.There were significant differences (P<0.05) in the FDDNP DVR and FDG Ki values in the parietal and temporal regions after MC.In conclusion, MC applied to dynamic brain FDDNP and FDG PET/CT scans could improve the qualitative and quantitative aspects of images of both tracers.

View Article: PubMed Central - PubMed

Affiliation: Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America.

ABSTRACT
Head movement during a dynamic brain PET/CT imaging results in mismatch between CT and dynamic PET images. It can cause artifacts in CT-based attenuation corrected PET images, thus affecting both the qualitative and quantitative aspects of the dynamic PET images and the derived parametric images. In this study, we developed an automated retrospective image-based movement correction (MC) procedure. The MC method first registered the CT image to each dynamic PET frames, then re-reconstructed the PET frames with CT-based attenuation correction, and finally re-aligned all the PET frames to the same position. We evaluated the MC method's performance on the Hoffman phantom and dynamic FDDNP and FDG PET/CT images of patients with neurodegenerative disease or with poor compliance. Dynamic FDDNP PET/CT images (65 min) were obtained from 12 patients and dynamic FDG PET/CT images (60 min) were obtained from 6 patients. Logan analysis with cerebellum as the reference region was used to generate regional distribution volume ratio (DVR) for FDDNP scan before and after MC. For FDG studies, the image derived input function was used to generate parametric image of FDG uptake constant (Ki) before and after MC. Phantom study showed high accuracy of registration between PET and CT and improved PET images after MC. In patient study, head movement was observed in all subjects, especially in late PET frames with an average displacement of 6.92 mm. The z-direction translation (average maximum = 5.32 mm) and x-axis rotation (average maximum = 5.19 degrees) occurred most frequently. Image artifacts were significantly diminished after MC. There were significant differences (P<0.05) in the FDDNP DVR and FDG Ki values in the parietal and temporal regions after MC. In conclusion, MC applied to dynamic brain FDDNP and FDG PET/CT scans could improve the qualitative and quantitative aspects of images of both tracers.

Show MeSH
Related in: MedlinePlus