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Comparing approaches to correct for respiratory motion in NH3 PET-CT cardiac perfusion imaging.

Schleyer PJ, O'Doherty MJ, Barrington SF, Morton G, Marsden PK - Nucl Med Commun (2013)

Bottom Line: However, cases were found where alignment worsened and severe artefacts resulted.This occurred in more cases and to a greater extent for the averaged and gated CT, where the anterior wall intensity reduced by more than 10% in 21 and 24 cases, respectively, compared with six cases for the pseudo-gated CT.The pseudo-gated CT was found to be the most robust method.

View Article: PubMed Central - PubMed

Affiliation: Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, UK.

ABSTRACT

Aim: Respiratory motion affects cardiac PET-computed tomography (CT) imaging by reducing attenuation correction (AC) accuracy and by introducing blur. The aim of this study was to compare three approaches for reducing motion-induced AC errors and evaluate the inclusion of respiratory motion correction.

Materials and methods: AC with a helical CT was compared with averaged cine and gated cine CT, as well as with a pseudo-gated CT, which was produced by applying PET-derived motion fields to the helical CT. Data-driven gating was used to produce respiratory-gated PET and CT images, and 60 NH3 PET scans were attenuation corrected with each of the CTs. Respiratory motion correction was applied to the gated and pseudo-gated attenuation-corrected PET images.

Results: Anterior and lateral wall intensity measured in attenuation-corrected PET images generally increased when PET-CT alignment improved and decreased when alignment degraded. On average, all methods improved PET-CT liver and cardiac alignment, and increased anterior wall intensity by more than 10% in 36, 33 and 25 cases for the averaged, gated and pseudo-gated CTAC PET images, respectively. However, cases were found where alignment worsened and severe artefacts resulted. This occurred in more cases and to a greater extent for the averaged and gated CT, where the anterior wall intensity reduced by more than 10% in 21 and 24 cases, respectively, compared with six cases for the pseudo-gated CT. Application of respiratory motion correction increased the average anterior and inferior wall intensity, but only 13% of cases increased by more than 10%.

Conclusion: All methods improved average respiratory-induced AC errors; however, some severe artefacts were produced. The pseudo-gated CT was found to be the most robust method.

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For the anterior (a) and inferior (b) walls, a significant (P<0.05) correlation was found between the effect of respiratory motion correction (the change in profile maximum measured on ACRegGCT and ACRegpseudo) and the range of respiratory-induced motion measured on NAC-gated PET images. No correlation was found for the septal and lateral walls. NAC, non-attenuation-corrected.
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Figure 5: For the anterior (a) and inferior (b) walls, a significant (P<0.05) correlation was found between the effect of respiratory motion correction (the change in profile maximum measured on ACRegGCT and ACRegpseudo) and the range of respiratory-induced motion measured on NAC-gated PET images. No correlation was found for the septal and lateral walls. NAC, non-attenuation-corrected.

Mentions: Application of respiratory motion correction to the ACGCT and ACpseudo PET images significantly increased the intensity of all SA walls (P<0.05), with the largest change seen in the anterior and inferior walls, as shown in Table 4. The change in wall intensity was significantly correlated with total respiratory motion range for the anterior and inferior walls (P<0.001); however, no correlation was found for the septal and lateral walls. This is demonstrated in Fig. 5, which shows the change in cardiac wall intensities measured on ACRegGCT and ACRegpseudo images, with respect to the total respiratory-induced displacement range measured on NAC PET images.


Comparing approaches to correct for respiratory motion in NH3 PET-CT cardiac perfusion imaging.

Schleyer PJ, O'Doherty MJ, Barrington SF, Morton G, Marsden PK - Nucl Med Commun (2013)

For the anterior (a) and inferior (b) walls, a significant (P<0.05) correlation was found between the effect of respiratory motion correction (the change in profile maximum measured on ACRegGCT and ACRegpseudo) and the range of respiratory-induced motion measured on NAC-gated PET images. No correlation was found for the septal and lateral walls. NAC, non-attenuation-corrected.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3815144&req=5

Figure 5: For the anterior (a) and inferior (b) walls, a significant (P<0.05) correlation was found between the effect of respiratory motion correction (the change in profile maximum measured on ACRegGCT and ACRegpseudo) and the range of respiratory-induced motion measured on NAC-gated PET images. No correlation was found for the septal and lateral walls. NAC, non-attenuation-corrected.
Mentions: Application of respiratory motion correction to the ACGCT and ACpseudo PET images significantly increased the intensity of all SA walls (P<0.05), with the largest change seen in the anterior and inferior walls, as shown in Table 4. The change in wall intensity was significantly correlated with total respiratory motion range for the anterior and inferior walls (P<0.001); however, no correlation was found for the septal and lateral walls. This is demonstrated in Fig. 5, which shows the change in cardiac wall intensities measured on ACRegGCT and ACRegpseudo images, with respect to the total respiratory-induced displacement range measured on NAC PET images.

Bottom Line: However, cases were found where alignment worsened and severe artefacts resulted.This occurred in more cases and to a greater extent for the averaged and gated CT, where the anterior wall intensity reduced by more than 10% in 21 and 24 cases, respectively, compared with six cases for the pseudo-gated CT.The pseudo-gated CT was found to be the most robust method.

View Article: PubMed Central - PubMed

Affiliation: Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, UK.

ABSTRACT

Aim: Respiratory motion affects cardiac PET-computed tomography (CT) imaging by reducing attenuation correction (AC) accuracy and by introducing blur. The aim of this study was to compare three approaches for reducing motion-induced AC errors and evaluate the inclusion of respiratory motion correction.

Materials and methods: AC with a helical CT was compared with averaged cine and gated cine CT, as well as with a pseudo-gated CT, which was produced by applying PET-derived motion fields to the helical CT. Data-driven gating was used to produce respiratory-gated PET and CT images, and 60 NH3 PET scans were attenuation corrected with each of the CTs. Respiratory motion correction was applied to the gated and pseudo-gated attenuation-corrected PET images.

Results: Anterior and lateral wall intensity measured in attenuation-corrected PET images generally increased when PET-CT alignment improved and decreased when alignment degraded. On average, all methods improved PET-CT liver and cardiac alignment, and increased anterior wall intensity by more than 10% in 36, 33 and 25 cases for the averaged, gated and pseudo-gated CTAC PET images, respectively. However, cases were found where alignment worsened and severe artefacts resulted. This occurred in more cases and to a greater extent for the averaged and gated CT, where the anterior wall intensity reduced by more than 10% in 21 and 24 cases, respectively, compared with six cases for the pseudo-gated CT. Application of respiratory motion correction increased the average anterior and inferior wall intensity, but only 13% of cases increased by more than 10%.

Conclusion: All methods improved average respiratory-induced AC errors; however, some severe artefacts were produced. The pseudo-gated CT was found to be the most robust method.

Show MeSH