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. 2017 Feb:10132:1013213.
doi: 10.1117/12.2255303. Epub 2017 Mar 9.

Deformable Known Component Model-Based Reconstruction for Coronary CT Angiography

X Zhang  1 , S Tilley  1 , S Xu  1 , A Mathews  1 , E R McVeigh  2 , J W Stayman  1
Affiliations

Deformable Known Component Model-Based Reconstruction for Coronary CT Angiography

X Zhang et al. Proc SPIE Int Soc Opt Eng. 2017 Feb.

Abstract

Purpose: Atherosclerosis detection remains challenging in coronary CT angiography for patients with cardiac implants. Pacing electrodes of a pacemaker or lead components of a defibrillator can create substantial blooming and streak artifacts in the heart region, severely hindering the visualization of a plaque of interest. We present a novel reconstruction method that incorporates a deformable model for metal leads to eliminate metal artifacts and improve anatomy visualization even near the boundary of the component.

Methods: The proposed reconstruction method, referred as STF-dKCR, includes a novel parameterization of the component that integrates deformation, a 3D-2D preregistration process that estimates component shape and position, and a polyenergetic forward model for x-ray propagation through the component where the spectral properties are jointly estimated. The methodology was tested on physical data of a cardiac phantom acquired on a CBCT testbench. The phantom included a simulated vessel, a metal wire emulating a pacing lead, and a small Teflon sphere attached to the vessel wall, mimicking a calcified plaque. The proposed method was also compared to the traditional FBP reconstruction and an interpolation-based metal correction method (FBP-MAR).

Results: Metal artifacts presented in standard FBP reconstruction were significantly reduced in both FBP-MAR and STF-dKCR, yet only the STF-dKCR approach significantly improved the visibility of the small Teflon target (within 2 mm of the metal wire). The attenuation of the Teflon bead improved to 0.0481 mm-1 with STF-dKCR from 0.0166 mm-1 with FBP and from 0.0301 mm-1 with FBP-MAR - much closer to the expected 0.0414 mm-1.

Conclusion: The proposed method has the potential to improve plaque visualization in coronary CT angiography in the presence of wire-shaped metal components.

Keywords: CT reconstruction; implant imaging; metal artifact reduction; penalized-likelihood estimation.

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Figures

Figure 1:
Figure 1:
Illustration of implant parameterization that includes deformation and radius variables.
Figure 2.
Figure 2.
The heart-lung complex was modified to include a water-filled tube to emulate a coronary vessel. A metal wire was placed in the vessel and a small Teflon bead was included to emulate a calcification.
Figure 3.
Figure 3.
Physical measurement data of the test phantom were acquired on an experimental CBCT bench.
Figure 4.
Figure 4.
Performance assessment of the STF-dKCR method. Axial, sagittal, and coronal views are shown for (A) the FBP reconstruction, (B) the FBP-MAR reconstruction, and (C) the STF-dKCR volume. The registered, wire-like component is shown as a red overlay in the STF-dKCR reconstruction. The Teflon sphere is indicated in each view by a yellow arrow.
Figure 5.
Figure 5.
(A) quantitative measurement of the Teflon volume attenuation for FBP, FBP-MAR, and STF-dKCR and (B) the estimated spectral coefficient values.
See this image and copyright information in PMC

References

    1. Mlynarski R, Sosnowski M, Mlynarska A., Tendera M, “Computed tomography in patients with cardiac pacemakers: difficulties and solutions,” Heart Vessels, 1–7 (2011). - PubMed
    1. Kalender WA, Hebel R., Ebersberger J, “Reduction of CT artifacts caused by metallic implants.,” Radiology 164(2), 576–577 (1987). - PubMed
    1. Watzke O., Kalender WA, “A pragmatic approach to metal artifact reduction in CT: merging of metal artifact reduced images.,” Eur. Radiol 14(5), 849–856 (2004). - PubMed
    1. Li H, Yu L, Liu X., McCollough CH, “Metal artifact suppression from reformatted projections in multi-slice helical CT using dual-front active contours,” Proc. 31st Annu. Int. Conf. IEEE Eng. Med. Biol. Soc. Eng. Futur. Biomed. EMBC 2009 5155(2010), 993–996 (2009). - PubMed
    1. Xinhui D, Zhang L., Xiao Y., Cheng J., Chen Z., Xing Y., “Metal artifact reduction in CT images by sinogram TV inpainting,” 2008 IEEENucl. Sci. Symp. Conf. Rec., 4175–1177, IEEE; (2008).

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