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

Eur Radiol. 2013 Oct;23(10):2687-94. doi: 10.1007/s00330-013-2885-z. Epub 2013 May 19.


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.

MeSH terms

  • Aged
  • Algorithms
  • Angiography / methods*
  • Artifacts*
  • Carotid Arteries / diagnostic imaging
  • Carotid Artery Diseases / diagnostic imaging*
  • Dental Implants*
  • Female
  • Humans
  • Male
  • Metals*
  • Radiographic Image Enhancement / methods
  • Radiographic Image Interpretation, Computer-Assisted / methods*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed / methods*


  • Dental Implants
  • Metals