European Radiology

, Volume 23, Issue 10, pp 2687–2694 | Cite as

Metal artefact reduction from dental hardware in carotid CT angiography using iterative reconstructions

  • Fabian Morsbach
  • Moritz Wurnig
  • Daniel M. Kunz
  • Andreas Krauss
  • Bernhard Schmidt
  • Spyros S. Kollias
  • Hatem Alkadhi
Computed Tomography

Abstract

Purpose

To determine the value of a metal artefact reduction (MAR) algorithm with iterative reconstructions for dental hardware in carotid CT angiography.

Methods

Twenty-four patients (six of which were women; mean age 70 ± 12 years) with dental hardware undergoing carotid CT angiography were included. Datasets were reconstructed with filtered back projection (FBP) and using a MAR algorithm employing normalisation and an iterative frequency-split (IFS) approach. Three blinded, independent readers measured CT attenuation values and evaluated image quality and degrees of artefacts using axial images, multi-planar reformations (MPRs) and maximal intensity projections (MIP) of the carotid arteries.

Results

CT attenuation values of the internal carotid artery on images with metal artefacts were significantly higher in FBP (324 ± 104HU) datasets compared with those reconstructed with IFS (278 ± 114HU; P < 0.001) and with FBP on images without metal artefacts (293 ± 106HU; P = 0.006). Quality of IFS images was rated significantly higher on axial, MPR and MIP images (P < 0.05, each), and readers found significantly less artefacts impairing the diagnostic confidence of the internal carotid artery (P < 0.05, each).

Conclusion

The MAR algorithm with the IFS approach allowed for a significant reduction of artefacts from dental hardware in carotid CT angiography, hereby increasing image quality and improving the accuracy of CT attenuation measurements.

Key points

CT angiography of the neck has proven value for evaluating carotid disease

Neck CT angiography images are often degraded by artefacts from dental implants

A metal artefact reduction algorithm with iterative reconstruction reduces artefacts significantly

Visualisation of the internal carotid artery is improved

Keywords

Metal artefact reduction Computed tomography angiography Dental implants Internal carotid artery Carotid angiography 

Abbreviations

MAR

Metal artefact reduction

IFS

Iterative frequency split

MPR

Multiplanar reformation

MIP

Maximum intensity projection

FBP

Filtered back projection

NMAR

Normalised metal artefact reduction

References

  1. 1.
    Utter GH, Hollingworth W, Hallam DK, Jarvik JG, Jurkovich GJ (2006) Sixteen-slice CT angiography in patients with suspected blunt carotid and vertebral artery injuries. J Am Coll Surg 203:838–848PubMedCrossRefGoogle Scholar
  2. 2.
    Delgado Almandoz JE, Romero JM, Pomerantz SR, Lev MH (2010) Computed tomography angiography of the carotid and cerebral circulation. Radiol Clin North Am 48:265–281, vii–viiiPubMedCrossRefGoogle Scholar
  3. 3.
    Josephson SA, Bryant SO, Mak HK, Johnston SC, Dillon WP, Smith WS (2004) Evaluation of carotid stenosis using CT angiography in the initial evaluation of stroke and TIA. Neurology 63:457–460PubMedCrossRefGoogle Scholar
  4. 4.
    Koelemay MJ, Nederkoorn PJ, Reitsma JB, Majoie CB (2004) Systematic review of computed tomographic angiography for assessment of carotid artery disease. Stroke 35:2306–2312PubMedCrossRefGoogle Scholar
  5. 5.
    Latchaw RE, Alberts MJ, Lev MH et al (2009) Recommendations for imaging of acute ischemic stroke: a scientific statement from the American Heart Association. Stroke 40:3646–3678PubMedCrossRefGoogle Scholar
  6. 6.
    Kim JJ, Dillon WP, Glastonbury CM, Provenzale JM, Wintermark M (2010) Sixty-four-section multidetector CT angiography of carotid arteries: a systematic analysis of image quality and artifacts. AJNR Am J Neuroradiol 31:91–99PubMedCrossRefGoogle Scholar
  7. 7.
    Ramgren B, Bjorkman-Burtscher IM, Holtas S, Siemund R (2012) CT angiography of intracranial arterial vessels: impact of tube voltage and contrast media concentration on image quality. Acta Radiol 53:929–934PubMedCrossRefGoogle Scholar
  8. 8.
    Kuroda Y, Hosoya T, Oda A et al (2011) Inverse-direction scanning improves the image quality of whole carotid CT angiography with 64-MDCT. Eur J Radiol 80:749–754PubMedCrossRefGoogle Scholar
  9. 9.
    Saba L, Mallarin G (2009) Window settings for the study of calcified carotid plaques with multidetector CT angiography. AJNR Am J Neuroradiol 30:1445–1450PubMedCrossRefGoogle Scholar
  10. 10.
    Barrett JF, Keat N (2004) Artifacts in CT: recognition and avoidance. Radiographics 24:1679–1691PubMedCrossRefGoogle Scholar
  11. 11.
    Borisch I, Boehme T, Butz B, Hamer OW, Feuerbach S, Zorger N (2007) Screening for carotid injury in trauma patients: image quality of 16-detector-row computed tomography angiography. Acta Radiol 48:798–805PubMedCrossRefGoogle Scholar
  12. 12.
    Lell MM, Hinkmann F, Nkenke E et al (2010) Dual energy CTA of the supraaortic arteries: technical improvements with a novel dual source CT system. Eur J Radiol 76:e6–e12PubMedCrossRefGoogle Scholar
  13. 13.
    Watzke O, Kalender WA (2004) A pragmatic approach to metal artifact reduction in CT: merging of metal artifact reduced images. Eur Radiol 14:849–856PubMedCrossRefGoogle Scholar
  14. 14.
    Kalender WA, Hebel R, Ebersberger J (1987) Reduction of CT artifacts caused by metallic implants. Radiology 164:576–577PubMedGoogle Scholar
  15. 15.
    Boas FE, Fleischmann D (2011) Evaluation of two iterative techniques for reducing metal artifacts in computed tomography. Radiology 259:894–902PubMedCrossRefGoogle Scholar
  16. 16.
    De Man B, Nuyts J, Dupont P, Marchal G, Suetens P (2001) An iterative maximum-likelihood polychromatic algorithm for CT. IEEE Trans Med Imaging 20:999–1008PubMedCrossRefGoogle Scholar
  17. 17.
    Dong J, Kondo A, Abe K, Hayakawa Y (2011) Successive iterative restoration applied to streak artifact reduction in X-ray CT image of dento-alveolar region. Int J Comput Assist Radiol Surg 6:635–640PubMedCrossRefGoogle Scholar
  18. 18.
    Bamberg F, Dierks A, Nikolaou K, Reiser MF, Becker CR, Johnson TR (2011) Metal artifact reduction by dual energy computed tomography using monoenergetic extrapolation. Eur Radiol 21:1424–142PubMedCrossRefGoogle Scholar
  19. 19.
    Guggenberger R, Winklhofer S, Osterhoff G et al (2012) Metallic artefact reduction with monoenergetic dual-energy CT: systematic ex vivo evaluation of posterior spinal fusion implants from various vendors and different spine levels. Eur Radiol 22:2357–2364PubMedCrossRefGoogle Scholar
  20. 20.
    Stolzmann P, Winklhofer S, Schwendener N, Alkadhi H, Thali MJ, Ruder TD (2013) Monoenergetic computed tomography reconstructions reduce beam hardening artifacts from dental restorations. Forensic Sci Med Pathol. doi:10.1007/s12024-013-9420-z
  21. 21.
    Meyer E, Raupach R, Lell M, Schmidt B, Kachelriess M (2012) Frequency split metal artifact reduction (FSMAR) in computed tomography. Med Phys 39:1904–1916PubMedCrossRefGoogle Scholar
  22. 22.
    Lell MM, Meyer E, Kuefner MA et al (2012) Normalized metal artifact reduction in head and neck computed tomography. Invest Radiol 47:415–421PubMedCrossRefGoogle Scholar
  23. 23.
    Morsbach F, Bickelhaupt S, Wanner GA, Krauss A, Schmidt B, Alkadhi H (2013) Reduction of metal artifacts from hip prostheses on CT images of the pelvis: value of iterative reconstructions. Radiology. doi:10.1148/radiol.13122089
  24. 24.
    Meyer E, Raupach R, Lell M, Schmidt B, Kachelriess M (2010) Normalized metal artifact reduction (NMAR) in computed tomography. Med Phys 37:5482–5493PubMedCrossRefGoogle Scholar
  25. 25.
    Bouthillier A, van Loveren HR, Keller JT (1996) Segments of the internal carotid artery: a new classification. Neurosurgery 38:425–432, discussion 432–423PubMedGoogle Scholar
  26. 26.
    Shrout PE, Fleiss JL (1979) Intraclass correlations: uses in assessing rater reliability. Psychol Bull 86:420–428PubMedCrossRefGoogle Scholar
  27. 27.
    Brown JH, Lustrin ES, Lev MH, Ogilvy CS, Taveras JM (1999) Reduction of aneurysm clip artifacts on CT angiograms: a technical note. AJNR Am J Neuroradiol 20:694–696PubMedGoogle Scholar
  28. 28.
    Vertinsky AT, Schwartz NE, Fischbein NJ, Rosenberg J, Albers GW, Zaharchuk G (2008) Comparison of multidetector CT angiography and MR imaging of cervical artery dissection. AJNR Am J Neuroradiol 29:1753–1760PubMedCrossRefGoogle Scholar
  29. 29.
    Klinke T, Daboul A, Maron J et al (2012) Artifacts in magnetic resonance imaging and computed tomography caused by dental materials. PLoS One 7:e31766PubMedCrossRefGoogle Scholar
  30. 30.
    Rapalino O, Kamalian S, Payabvash S et al (2012) Cranial CT with adaptive statistical iterative reconstruction: improved image quality with concomitant radiation dose reduction. AJNR Am J Neuroradiol 33:609–615PubMedCrossRefGoogle Scholar
  31. 31.
    Kilic K, Erbas G, Guryildirim M, Arac M, Ilgit E, Coskun B (2011) Lowering the dose in head CT using adaptive statistical iterative reconstruction. AJNR Am J Neuroradiol 32:1578–1582PubMedCrossRefGoogle Scholar
  32. 32.
    Niu YT, Mehta D, Zhang ZR et al (2012) Radiation dose reduction in temporal bone CT with iterative reconstruction technique. AJNR Am J Neuroradiol 33:1020–1026PubMedCrossRefGoogle Scholar

Copyright information

© European Society of Radiology 2013

Authors and Affiliations

  • Fabian Morsbach
    • 1
  • Moritz Wurnig
    • 1
  • Daniel M. Kunz
    • 1
  • Andreas Krauss
    • 2
  • Bernhard Schmidt
    • 2
  • Spyros S. Kollias
    • 3
  • Hatem Alkadhi
    • 1
  1. 1.Institute of Diagnostic and Interventional RadiologyUniversity Hospital ZurichZurichSwitzerland
  2. 2.Siemens Healthcare, Imaging & Therapy Systems DivisionForchheimGermany
  3. 3.Department of NeuroradiologyUniversity Hospital ZurichZurichSwitzerland

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