In recent years the imaging capabilities of flat detector C-arm X-ray systems havebeen improved.
Flat Detector Computed Tomography(FDCT) has become increasingly popular within minimally invasiveendovascular interventions [1,2].
Very recently it has becomefeasible tovisualize stents that possess very low radiopacity.
The FDCT images offer the possibility to inspect the stent deployment with respect to the vessel lumen and intravascular plaques [3,4].
tomographic images of stents that are placed adjacent to aneurysms filled with coils areseverely distorted by streakingartifacts caused by the metal coils.
Methods and Materials
VasoCT - High resolution FDCT of intracranial stents
For the purpose of imaging intracranial stents and their surrounding vasculature a dedicated acquisition protocol and reconstruction settings have been developed (VasoCT; Philips Healthcare,
the Netherlands) .
The high resolution protocol consists of 620 projection images acquired over a rotational trajectory of 200°,
while the imaged detector area is set to a diameter of 22 cm and using a pixel size of 0.154 mm.
The X-ray tube voltage is set to 80 kV,
the focal spot...
Fig. 5shows a pre-interventional FDCTand a post coiling FDCTwithout and with MAR applied,
in order to illustrate the MAR technique.The streaking artifacts have been reduced significantly in the reconstruction with MAR applied.
Soft-tissue structures that are obstructed by the streaking artifacts origining from the coils in the aneurysm sac are clearly visible in the reconstruction with MAR.
In Fig. 6a reconstruction of a coiled aneurysm is shown,
while the vessels have been filled with diluted contrast medium.The second pass reconstruction (right) shows clearlythe vasculature obstructed...
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  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...
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