Sietske Rozie MD, Presenter: Nothing to Disclose

Piotr Alfred Wielopolski PhD, Abstract Co-Author: Nothing to Disclose

Mohammed Ouhlous, Abstract Co-Author: Nothing to Disclose

Wiro Niessen PhD, Abstract Co-Author: Nothing to Disclose

Theo Van Walsum, Abstract Co-Author: Nothing to Disclose

Aad Van Der Lugt MD, PhD, Abstract Co-Author: Research support, Bayer AG

Cerebrovascular events are related to atherosclerotic disease in the carotid artery. Atherosclerotic plaque rupture leading to thromboembolisation occurs in a specific type of atherosclerotic plaque (vulnerable plaque). Characterisation an quantification of atherosclerotic plaque may improve risk prediction. We hypothesize that a blood pool agent enhances the atherosclerotic carotid plaque and may improve characterization and quantification.

We studied 17 atherosclerotic plaques of nine patients (8 male; mean age 62.3 ± 9.2 years, range 47-75 years) with severe carotid stenosis (>50%) and cerebrovascular symptoms. These patients underwent multiple sequences on a 3.0T MRI (Signa Excite,GE Healthcare, USA) with a 4-channel bilateral coil to identify the various plaque components. We injected 0.03 mmol/kg of Vasovist® (Gadofosveset, Schering, Germany) and an axial 3D-T1-weighted sequence was performed 20 minutes after injection. We used a custom-made 3D point-based registration tool to match the images before and after contrast injection in order to correct for patient movements. In the images of the 3D-T1-weighted scans we measured the signal intensity (SI) of the sternocleidomastoideus muscle (SCM), the non-calcified part of the plaque and the vessel wall (outer border) of the carotid artery. The percentage contrast enhancement was calculated as : SI(enhanced)- SI(unenhanced) / SI(unenhanced) x 100.

The mean percentage enhancement on the post contrast scan was 25.8% ± 11.4% in the muscle (SCM), 41.4% ± 31.5% (range 1-120%) in the non-calcified part of the plaque and 58.2% ± 25.6% in the vessel wall of the symptomatic carotid arteries.

The atherosclerotic plaque and the vessel wall of the carotid artery enhances after injection of Vasovist® . The enhancement of the non-calcified part of the plaque has a large range which may reflect differences in plaque composition.

Images obtained before and after injection of contrast may improve atherosclerotic plaque characterisation. Quantification measurements of the plaque may improve after Vasovist injection because of the enhancement of the outer vessel wall.

Rozie, S, Wielopolski, P, Ouhlous, M, Niessen, W, Van Walsum, T, Van Der Lugt, A, Enhancement of the Atherosclerotic Plaque and the Vessel Wall of the Carotid Artery after Injection of a Blood Pool Agent.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5010738.html