Keywords:
Artifacts, Aneurysms, Stents, Embolisation, Computer Applications-3D, CT-High Resolution, CT-Angiography, Cone beam CT, Neuroradiology brain, Interventional vascular, Head and neck
Authors:
P. van de Haar, D. Ruijters, J. Timmer; Best/NL
DOI:
10.1594/ecr2013/C-1951
Conclusion
The MAR procedure significantly reduces the presence of metal streaking artifacts caused by coils placed in aneurysms.
This allows the investigation of tissue and anatomical structures adjacent to the coiled volume.
In case of stent/coils combinations this is especially valuable,
since the streaks tend to obscure the intracranial stent.
Observers in a recent study [8] gave significantly higher scores to MAR corrected FDCT images regarding the visibility of the arteries and stents adjacent to coiled aneurysms.
Especially when diluted iodine contrast medium is administrated to perform a VasoCT reconstruction,
enabling to examine the vascular morphology,
streaking artifacts severely disturb the evaluation of the aneurysm neck.
On top of that false vessel bifurcations and branches may be introduced by the streaking artifacts.
The MAR procedure largely resolves these disturbing phenomena.
It removes the false bifurcations and branches,
and enables the clear visualization of the aneurysm neck.
The improved second pass reconstructions significantly benefit the clinical interpretation of the tomographic images.
Especially,
the assessment of the stent deployment with respect to the vessel lumen is enhanced significantly for stents that are placed close to coiled aneurysms.
MAR cannot fully remove all metal artifacts.
Typically,
some streak-artifacts remain.
The intensity of the remaining streaks depends on the complexity of nearby anatomy (like bone structures),
size of metal object etc.
Soft-tissue imaging of very low-contrasts will still suffer from artifacts,
but the artifact level has been significantly reduced.
Overall the diagnostic value of the MAR reconstructed images has been greatly enhanced,
due to the considerable reduction of the artifacts.