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. 2012 Mar;41(3):217-23.
doi: 10.1259/dmfr/19015946.

Characterization and correction of cupping effect artefacts in cone beam CT

A K Hunter  1 , W D McDavid
Affiliations

Characterization and correction of cupping effect artefacts in cone beam CT

A K Hunter et al. Dentomaxillofac Radiol. 2012 Mar.

Abstract

Objective: The purpose of this study was to demonstrate and correct the cupping effect artefact that occurs owing to the presence of beam hardening and scatter radiation during image acquisition in cone beam CT (CBCT).

Methods: A uniform aluminium cylinder (6061) was used to demonstrate the cupping effect artefact on the Planmeca Promax 3D CBCT unit (Planmeca OY, Helsinki, Finland). The cupping effect was studied using a line profile plot of the grey level values using ImageJ software (National Institutes of Health, Bethesda, MD). A hardware-based correction method using copper pre-filtration was used to address this artefact caused by beam hardening and a software-based subtraction algorithm was used to address scatter contamination.

Results: The hardware-based correction used to address the effects of beam hardening suppressed the cupping effect artefact but did not eliminate it. The software-based correction used to address the effects of scatter resulted in elimination of the cupping effect artefact.

Conclusion: Compensating for the presence of beam hardening and scatter radiation improves grey level uniformity in CBCT.

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Figures

Figure 1
Figure 1
Cupping effect artefact
Figure 2
Figure 2
Pre-upgrade filtration (2.5 mm aluminium). Cupping effect 29%
Figure 3
Figure 3
Post-upgrade filtration (0.5 mm copper added). Cupping effect 17%
Figure 4
Figure 4
Additional filtration (1.06 mm copper added). Cupping effect 13%
Figure 5
Figure 5
Additional filtration (1.62 mm copper added). Cupping effect 10%
Figure 6
Figure 6
Planmeca model spectra at 80 kV and 8 mA
Figure 7
Figure 7
Post-upgrade filtration with scatter subtraction
See this image and copyright information in PMC

References

    1. Mozzo P, Procacci C, Tacconi A, Tinazzi Martini P, Bergamo Andreis IA. A new volumetric CT machine for dental imaging based on the cone-beam technique: preliminary results. Eur Radiol 1998;8:1558–1564 - PubMed
    1. Mol A, Balasundaram A. In vitro cone beam CT imaging of periodontal bone. Dentomaxillofac Radiol 2008;37:319–324 - PubMed
    1. Swennen GRJ, Mommaerts MY, Abeloos J, De Clercq C, Lamoral P, Neyt N, et al. A cone-beam CT based technique to augment the 3D virtual skull model with a detailed dental surface. Int J Oral Maxillofac Surg 2009;38:48–57 - PubMed
    1. Ludlow JB, Ivanovic M. Comparative dosimetry of dental CBCT devices and 64-slice CT for oral and maxillofacial radiology. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106:106–114 - PubMed
    1. Barrett JF, Keat N. Artifacts in CT: recognition and avoidance. Radiographics 2004;24:1679–1691 - PubMed