Antoine Millon, Abstract Co-Author: Nothing to Disclose

Loic Boussel MD, Abstract Co-Author: Nothing to Disclose

Marie Brevet, Abstract Co-Author: Nothing to Disclose

Jean-Louis Mathevet, Abstract Co-Author: Nothing to Disclose

Jean-Yves Scoazec, Abstract Co-Author: Nothing to Disclose

Philippe Charles Douek MD, PhD, Presenter: Nothing to Disclose

To evaluate clinical and histological significance of gadolinium (Gd) enhancement of carotid plaque in patients undergoing endarterectomy for carotid stenosis.

69 patients schedule for a carotid endarterectomy prospectively underwent a 3T High Resolution (HR) MRI with a dual surface coil. Carotid plaque enhancement was assessed on ECG triggered T1 weighted sequences using a double Inversion Recovery Black Blood preparation pulse and SPIR fat sat, performed before and 5 min after Gd injection. Enhancement was recorded regarding its localization (fibrous cap, shoulder or central into the plaque). Histological analysis were performed with assessment of large lipidic core, fibrous cap status (FC), intraplaque haemorrhage (IPH), macrophage infiltration, neovascularization and loose matrix of the entire plaque and of the area in tissue slices matched with contrast enhanced area on MR images.

10 patients were excluded because of motion artifact or histological massive calcifications. In the remaining 59 patients, 19 were symptomatic. Gd enhancement was observed in 35 patients: 7 in shoulder region, 8 in fibrous cap and shoulder region and 20 central into the plaque. FC rupture, IPH and plaque Gd enhancement were significantly more frequent in symptomatic than in asymptomatic patients (p=0.043; p<0.0001; p=0.034 respectively). After histological analysis, Gd enhancement was significantly associated with vulnerable plaque (AHA VI, p=0.006), neovascularization (p<0.0001), macrophages (p=0.030) and loose fibrosis (p<0.0001). Prevalence of neovessels, macrophages and loose fibrosis in the area of Gd enhancement was 79, 74 and 82% and was significantly different depending on the location: 100, 83 and 75% for shoulder enhancement, 12, 50 and 100% for fibrous cap enhancement and 94, 78 and 78% for central enhancement. Important loose fibrosis was exclusively observed in central enhancement. FC rupture was observed in the area of enhancement in 9.5% of the cases.

Gd enhancement of carotid plaque is associated with vulnerable plaque phenotypes and is related to an inflammatory process.

Gadolinium enhancement of carotid plaque can be considered as an additional feature of plaque vulnerability like intraplaque hemorrhage or fibrous cap rupture.

Millon, A, Boussel, L, Brevet, M, Mathevet, J, Scoazec, J, Douek, P, Clinical and Histological Significance of Gadolinium-enhancement of Carotid Atherosclerotic Plaque.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12037397.html