, Volume 59, Issue 7, pp 649–654 | Cite as

Follow-up CT and CT angiography after intracranial aneurysm clipping and coiling—improved image quality by iterative metal artifact reduction

  • Georg Bier
  • Malte Niklas Bongers
  • Johann-Martin Hempel
  • Anja Örgel
  • Till-Karsten Hauser
  • Ulrike Ernemann
  • Florian Hennersdorf
Diagnostic Neuroradiology



This paper aims to evaluate a new iterative metal artifact reduction algorithm for post-interventional evaluation of brain tissue and intracranial arteries.


The data of 20 patients that underwent follow-up cranial CT and cranial CT angiography after clipping or coiling of an intracranial aneurysm was retrospectively analyzed. After the images were processed using a novel iterative metal artifact reduction algorithm, images with and without metal artifact reduction were qualitatively evaluated by two readers, using a five-point Likert scale. Moreover, artifact strength was quantitatively assessed in terms of CT attenuation and standard deviation alterations.


The qualitative analysis yielded a significant increase in image quality (p = 0.0057) in iteratively processed images with substantial inter-observer agreement (ĸ = 0.72), while the CTA image quality did not differ (p = 0.864) and even showed vessel contrast reduction in six cases (30%). The mean relative attenuation difference was 27% without metal artifact reduction vs. 11% for iterative metal artifact reduction images (p = 0.0003).


The new iterative metal artifact reduction algorithm enhances non-enhanced CT image quality after clipping or coiling, but in CT-angiography images, the contrast of adjacent vessels can be compromised.


Computed tomography angiography Computed tomography Artifacts Head Aneurysm 


Compliance with ethical standards


No funding was received for this study.

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

For this type of retrospective study, formal consent is not required.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  • Georg Bier
    • 1
  • Malte Niklas Bongers
    • 2
  • Johann-Martin Hempel
    • 1
  • Anja Örgel
    • 1
  • Till-Karsten Hauser
    • 1
  • Ulrike Ernemann
    • 1
  • Florian Hennersdorf
    • 1
  1. 1.Department of Diagnostic and Interventional NeuroradiologyEberhard Karls University TuebingenTuebingenGermany
  2. 2.Department of Diagnostic and Interventional RadiologyEberhard Karls University TuebingenTuebingenGermany

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