1 3 Original article received: 11 June 2013 / accepted: 4 December 2013 © Springer-Verlag Berlin Heidelberg 2013 Grading of Carotid Artery Stenosis in the Presence of Extensive Calciications: Dual-Energy CT Angiography in Comparison with Contrast-Enhanced MR Angiography A. Korn · B. Bender · H. Brodoefel · T.-K. Hauser · S. Danz · U. Ernemann · C. Thomas clin neuroradiol DOi 10.1007/s00062-013-0276-0 before and multi-intensity projections (MiP) after plaque subtraction (PS) and compared with results from ce-Mra and DSa according to the north american Symptomatic carotid endarterectomy trial. Results average grades of stenoses were 80.7 ± 16.1 % (DSa), 81.4 ± 15.3 % (Mra), 80.0 ± 16.7 % (De-cta-MPr), and 85.2 ± 14.7 % (De-cta-PS-MiP). Of 21 stenoses, 6 were iliform (stenosis grade, 99 %) in the DSa examina- tion. Five of these cases were identiied as pseudo-occlu- sions in Mra, while four were considered as occlusions in DE-CTA-PS-MIP. Another four cases were identiied as pseudo-occlusion in De-cta-PS-MiP, which were identi- ied as 90 % stenosis in the DSa examination. Conclusions in comparison with the gold standard DSa, De-cta-MPr had a slightly better agreement in measur- ing the degree of stenosis of the internal carotid arteries than ce-Mra. in De-cta-PS-MiP images, a systematic overestimation has to be taken into account due to par- tial extinction of the lumen by the PS algorithm. never- theless, De-cta should be preferred in imaging patients with carotid artery stenosis in the presence of extensive calciications. Keywords Carotid artery stenosis · Calciied plaques · Dual-energy ct angiography · Mr angiography Introduction atherosclerosis of the extracranial internal carotid artery is a major cause of ischemic cerebral stroke [1]. Studies from the north american Symptomatic carotid endarterectomy trial (naScet) and the european carotid Surgery trial have proved that symptomatic patients with severe stenoses (70–99 %) can beneit from carotid endarterectomy [2–4]. Abstract Purpose We investigated the agreement of dual-energy computed tomography angiography (De-cta) and con- trast-enhanced magnetic resonance angiography (ce-Mra) in the quantitative measurement of stenoses of the internal carotid artery in comparison with digital subtraction angi- ography (DSa). Methods a total of 21 patients with stenoses of the external carotid artery were investigated with a De-cta and ce-Mra before undergoing carotid angioplasty. the grade of the ste- noses was assessed in axial multiplanar reformations (MPr) B. Bender, MD () · a. Korn, MD · t.-K. Hauser, MD · S. Danz, MD · U. ernemann, MD Department of Diagnostic and interventional neuroradiology, University of tübingen, Hoppe-Seyler-Str. 3, 72076 tübingen, germany e-mail: benjamin.bender@med.uni-tuebingen.de a. Korn, MD e-mail: andreas.korn@med.uni-tuebingen.de t.-K. Hauser, MD e-mail: till-karsten.hauser@med.uni-tuebingen.de S. Danz, MD e-mail: soeren.danz@med.uni-tuebingen.de U. ernemann, MD e-mail: ulrike.ernemann@med.uni-tuebingen.de H. Brodoefel, MD · c. thomas, MD Department of Diagnostic and interventional radiology, University of tübingen, Hoppe-Seyler-Str. 3, 72076 tübingen, germany e-mail: harald.brodoefel@med.uni-tuebingen.de c. thomas, MD e-mail: christoph.thomas@med.uni-tuebingen.de