Combining monoenergetic extrapolations from dual-energy CT with iterative reconstructions: reduction of coil and clip artifacts from intracranial aneurysm therapy.

Abstract

PURPOSE:

To compare and to combine iterative metal artifact reduction (MAR) and virtual monoenergetic extrapolations (VMEs) from dual-energy computed tomography (DECT) for reducing metal artifacts from intracranial clips and coils.

METHODS:

Fourteen clips and six coils were scanned in a phantom model with DECT at 100 and 150SnkVp. Four datasets were reconstructed: non-corrected images (filtered-back projection), iterative MAR, VME from DECT at 120 keV, and combined iterative MAR + VME images. Artifact severity scores and visibility of simulated, contrast-filled, adjacent vessels were assessed qualitatively and quantitatively by two independent, blinded readers.

RESULTS:

Iterative MAR, VME, and combined iterative MAR + VME resulted in a significant reduction of qualitative (p < 0.001) and quantitative clip artifacts (p < 0.005) and improved the visibility of adjacent vessels (p < 0.05) compared to non-corrected images, with lowest artifact scores found in combined iterative MAR + VME images. Titanium clips demonstrated less artifacts than Phynox clips (p < 0.05), and artifact scores increased with clip size. Coil artifacts increased with coil size but were reducible when applying iterative MAR + VME compared to non-corrected images. However, no technique improved the severe artifacts from large, densely packed coils.

CONCLUSIONS:

Combining iterative MAR with VME allows for an improved metal artifact reduction from clips and smaller, loosely packed coils. Limited value was found for large and densely packed coils.

• Authors: Sebastian Winklhofer, Ricarda Hinzpeter, Daniel Stocker, Gerasimos Baltsavias, Lars Michels, Jan-Karl Burkhardt, Luca Regli, Antonios Valavanis, Hatem Alkadhi
• Journal: Neuroradiology (Neuroradiology) Vol. 60 Issue 3 Pg. 281-291 (Mar 2018) ISSN: 1432-1920 [Electronic] Germany
• PMID: 29356855 (Publication Type: Journal Article)

Chemical References

• Contrast Media
• Metals

Topics

• Artifacts
• Contrast Media
• Humans
• Intracranial Aneurysm (diagnostic imaging, therapy)
• Metals
• Phantoms, Imaging
• Prostheses and Implants
• Radiographic Image Interpretation, Computer-Assisted (methods)
• Tomography, X-Ray Computed (methods)