Usefulness of monochromatic imaging with metal artifact reduction software for computed tomography angiography after intracranial aneurysm coil embolization

Acta Radiol. 2014 Oct;55(8):1015-23. doi: 10.1177/0284185113510492. Epub 2013 Nov 11.


Background: Recently, a newly developed fast-kV switching dual energy CT scanner with a gemstone detector generates virtual high keV images as monochromatic imaging (MI). Each MI can be reconstructed by metal artifact reduction software (MARS) to reduce metal artifact.

Purpose: To evaluate the degree of metal artifacts reduction and vessel visualization around the platinum coils using dual energy CT with MARS.

Material and methods: Dual energy CT was performed using a Discovery CT750 HD scanner (GE Healthcare, Milwaukee, WI, USA). In a phantom study, we measured the mean standard deviation within regions of interest around a 10-mm-diameter platinum coil mass on MI with and without MARS. Thirteen patients who underwent CTA after endovascular embolization for cerebral aneurysm with platinum coils were included in a clinical study. We visually assessed the arteries around the platinum coil mass on MI with and without MARS.

Results: Each standard deviation near the coil mass on MI with MARS was significantly lower than that without MARS in a phantom study. On CTA of a clinical study, better visibility of neighboring arteries was obtained in 11 of 13 patients on MI with MARS compared to without MARS due to metal artifact reduction.

Conclusion: Dual energy CT with MARS reduces metal artifact of platinum coils, resulting in favorable vessel visualization around the coil mass on CTA after embolization.

Keywords: CNS; CT angiography; aneurysms; metal artifact.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Artifacts*
  • Basilar Artery / diagnostic imaging
  • Cerebral Arteries / diagnostic imaging*
  • Contrast Media
  • Embolization, Therapeutic / methods*
  • Female
  • Humans
  • Image Processing, Computer-Assisted / methods*
  • Intracranial Aneurysm / diagnostic imaging
  • Intracranial Aneurysm / therapy*
  • Iopanoic Acid / analogs & derivatives
  • Male
  • Middle Aged
  • Phantoms, Imaging
  • Platinum
  • Radiographic Image Enhancement / methods
  • Retrospective Studies
  • Software
  • Tomography, X-Ray Computed / methods*


  • Contrast Media
  • Platinum
  • iopanoate glucuronide
  • Iopanoic Acid