CT-imaging of a hip prosthesis using model-based iterative reconstruction and its influence on metal artefact reduction: a quantitative analysis

This poster is published under an open license. Please read the disclaimer for further details.

Congress:

ECR 2015

Poster Number:

B-0567

Type:

Scientific Paper

Keywords:

Musculoskeletal bone, Pelvis, Radiation physics, CT, CT-Quantitative, Experimental investigations, Diagnostic procedure, Dosimetry, Prostheses, Dosimetric comparison

Authors:

R. H. H. Wellenberg¹, M. F. Boomsma¹, J. van Osch¹, A. Vlassenbroek², J. Milles³, D. Mueller⁴, M. Maas⁵; ¹Zwolle/NL, ²Best/NL, ³Eindhoven/NL, ⁴Hamburg/DE, ⁵Amsterdam/NL

DOI:

10.1594/ecr2015/B-0567

DOI-Link:

https://dx.doi.org/10.1594/ecr2015/B-0567

Fig. 1: Severe metal artefacts in bilateral hip prostheses CT imaging.

Fig. 5: FBP, IR and MBIR images with and without the use of O-MAR, focused at the head...

Fig. 6: CNR of the most severely affected pellet L8.

Fig. 7: Clearly superior image quality of a MBIR image at a third of the dose relative...

Purpose

In CT-imaging metallic composites can cause severe artefacts, especially in case of a large Metal-on-Metal (MoM) hip prostheses used for total hip arthroplasties (THA). Sufficient photon detection is severely distorted due to photon-starvation, beam hardening and scatter resulting in sub-optimal image quality, illustrated in Figure 1. Obtaining a reliable diagnose of pseudo-tumours, capsular reactions and other weak tissue pathologies is difficult or even impossible. These days several metal artefact reduction (MAR) techniques have shown to be valuable. One of these MAR techniques is the orthopaedic...

Methods and materials

A water-filled phantom was used made of PMMA containing a metal-on-metal prosthesis surrounded by 18 hydroxyapatite pellets representing bone illustrated in Figure 2.Scans were acquired on a 256-slice CT scanner at low, normal and high dose (CTDIvol of 10, 20 and 30 mGy) at three different tube voltages of 100, 120 and 140 kVp. These 9 different acquisitions were obtained with and without the insertion of a MoM-prosthesis where the phantom without the prosthesis referred as a reference. All images were reconstructed with Filtered Back...

Results

At identical dose-levels, mean CNR of 6.41, 10.09, 25.82 (p<0.001) and noise levels [HU] of 50.00, 29.87, and 10.66 (p<0.001) were obtained for FBP, IR and MBIR respectively. These measurements were obtained by averaging the values of all pellets without the insertion of a prosthesis. Even at half-dose CNR is higher and noise is reduced with MBIR when compared with FBP and IR at normal and high dose in a clinical setting. Pellet L0 and L4 were unaffected by metal artefacts due to their location...

Conclusion

MBIR combined with O-MAR significantly improves CNR and reduces noise and metal artefacts for imaging of MoM-prosthesis. O-MAR is most effective when combined with MBIR relative to IR and FBP. Image quality with MBIR is superior compared to FBP andIRat all dose levels both with and without the insertion of a prosthesis. MBIR in combination O-MAR allows for significant dose reduction while maintaining sufficient image quality.

Personal information

R.H.H. Wellenberg, Master student Technical Medicine, Isala, Zwolle, The Netherlands

References

[1] White paper. Metal-Artifact-Reduction for-Orthopedic-Implants-(O-MAR). 12-04 2014. [2] Huang Y, Zhao T, Jiang Y, Liu Y, Zhao Y, Xu K. Knowledge based iterative reconstructiontechnique reduces noise and improves image quality for low dose thyroid CT. ECR 2014 / C-1423. [3] Halpern E, Gingold E, White H, Read K. Evaluation of Coronary Artery Image Quality withKnowledge-based Iterative Model Reconstruction. Academic Radiology. 2014;21(6):805-811. [4] Oda S, Utsunomiya D, Funama Y, Katahira K, Honda K, Tokuyasu S, Vembar M, Yuki H, NodaK, Oshima S, Yamashita Y. A Knowledge-based...