Silent MR Angiography (MRA) of intracranial and extracranial carotid arteries.

Ischemic stroke is mainly due to atherosclerotic disease in the carotid
bifurcation. For this reason, all patients with ischemic stroke are evaluated
for luminal stenosis in the carotid bifurcation, and carotid endarterectomy is
performed in patients with a stenosis with of >70%. Besides the carotid,
proximal stenosis at the aortic arch or intracranial stenosis can be the
underlying cause of ischemic stroke. There is gradual shift occurring, from
focussed evaluation of only the carotid bifurcation (e.g. with duplex
ultrasound or (TOF MRA) towards comprehensive evaluation of the supra-aortic
arteries from the aortic arch to the intracranial circulation (e.g. CT
angiography, CEMRA).

Recently a new sequence is developed. Silent MR techniques based on zero TE
technology have the advantage of reducing acoustic noise during acquisition,
which improves patient comfort and cooperation. The question still to be
answered is whether image quality and accuracy is affected by this new
approach. The zero TE approach in combination with a read out that follows a
spiral path might also provide additional features for optimization of image
quality. For evaluation of atherosclerotic disease in the carotid bifurcation,
Zero TE MRI and MRA might reduce motion and flow artifacts which normally
hamper accurate evaluation.

CTA and CEMRA require the injection of contrast agents. Silent MRA with ASL
preparation might replace CEMRA in the evaluation of the supra-aortic arteries.
Both the HNS coils as well as the radiation therapy open head & neck coil suite
could be used for signal reception. The performance of the two coils will be
compared.
The proposed studies will demonstrate what the additional value is of the
Silent MRI in the visualization in patients with known atherosclerotic disease
in the carotid bifurcation . The studies will make clear whether the next
phase, clinical use of the sequences, is warranted.

Test the optimized MRI sequences/technology against CTA as gold standard, in
terms of
image quality, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR),
speed, and
accuracy/reproducibility of extracted quantitative parameters.

Observational diagnostic study

MRI scan fora maximum 40 minutes and exposure to acoustic noise. Other than
that no major risks for the individual subject.
There are no benefits to the individual subject..
Benefits to the Population: This study will show the value of a new MRI
sequence for intracranial coiled aneurysms.