Positive calcium scores in the carotid arteries indicate carotid bifurcation stenosis

Transcription

1 Positive calcium scores in the carotid arteries indicate carotid bifurcation stenosis Poster No.: C-2259 Congress: ECR 2011 Type: Scientific Paper Authors: N. Gotovac 1, I. Išgum 2, B. K. Velthius 2, M. A. Viergever 2, J. Keywords: DOI: Fajdi# 1, M. Prokop 3 ; 1 Pozega/HR, 2 Utrecht/NL, 3 Nijmegen/NL Vascular, Arteries / Aorta, CT-Angiography, CT, Diagnostic procedure, Arteriosclerosis, Ischemia / Infarction /ecr2011/C-2259 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 8

2 Purpose Carotid bifurcation stenosis is an important risk factor of stroke [1]. Stenosis is a consequence of atherosclerotic plaque formation (Figure 1). Reliable evaluation and quantification of stenosis degree and atherosclerotic plaque volume can be achieved with CT angiography (CTA) [2]. We investigated the relation between calcium scores in the aortic arch, extracranial and intracranial carotid arteries, and carotid bifurcation stenosis with CTA. Images for this section: Page 2 of 8

3 Fig. 1: Saggital reconstruction of carotid bifurcation stenosis (CTA), depicting partially calcified, mixed plaque (arrow), with non-significant stenosis Page 3 of 8

4 Methods and Materials We included 154 consecutive patients presenting with symptoms of TIA or stroke who received head and neck CTA imaging (16 or 64 slice MDCT, section thickness 1 and 0.6 mm respectively). A radiologist manually identified all calcifications in the aortic arch, carotid bifurcations, and intracranial part (siphon) of carotid arteries (Figure 1, left) using a threshold of 400 HU. Volume calcium scores were computed using in-house developed software [3]. Carotid bifurcation stenosis was evaluated as not present, not significant (<50%) or significant (>=50%) [4], according to the method described by Waaijer et al [2]. (Figure 1, right). To evaluate whether calcium scores in the measured segments indicate stenosis at the carotid bifurcation the area under the receiver-operatingcurve (ROC) was computed. Images for this section: Fig. 1: Extenisve calcifications (arrows) of internal carotid artery siphon (left), and >=50% stenosis of carotid bifurcation (right) in the same patient Page 4 of 8

5 Results Average patient age was 64 ± 14 years (41% female). Zero calcium score was found in 31/154 (20%) patients. Significant carotid bifurcation stenosis was detected in 35 patients only on the left side, in 32 only on the right side, and 23 patients had a bilateral stenosis. ROC analysis showed that calcium scores can indicate presence of significant carotid bifurcation stenosis (Figure 1 and Figure 2). Table 1 lists the obtained values under the ROC curves (Az). Left bifurcation Right bifurcation carotid carotid Significant stenosis at the right carotid bifurcation Significant stenosis at the left carotid bifurcation Aortic arch Left carotid siphon Right carotid siphon Significant stenosis at the left or right carotid bifurcation Table 1: Results of the ROC analysis. Az values showing calcium scores according to the arterial segment indicating a presence of significant stenosis in the left or in the right carotid bifurcation Images for this section: Page 5 of 8

6 Fig. 1: ROC curves for calcium scores and significant stenosis of the left carotid bifurcation (left), and of the right carotid bifurcation (right). Page 6 of 8

7 Fig. 2: ROC curves for calcium scores and significant stenosis of the left carotid bifurcation (left), and of the right carotid bifurcation (right). Page 7 of 8

8 Conclusion Presence of calcifications in the carotid siphon, bifurcations and aortic arch indicates significant carotid bifurcation stenosis in patients with acute stroke. This suggests that further work-up is called for. References 1. Furie KL, Kasner SE, Adams RJ, Albers GW, Bush RL, Fagan SC, Halperin JL, Johnston SC, Katzan I, Kernan WN, Mitchell PH, Ovbiagele B, Palesch YY, Sacco RL, Schwamm LH, Wassertheil-Smoller S, Turan TN, Wentworth D; American Heart Association Stroke Council, Council on Cardiovascular Nursing, Council on Clinical Cardiology, and Interdisciplinary Council on Quality of Care and Outcomes Research. (2011) Guidelines for the prevention of stroke in patients with stroke or transient ischemic attack: a guideline for healthcare professionals from the American heart ahssociation/ American stroke association. Stroke 42(1): Waaijer A, Weber M, van Leeuwen MS, Veldhuis WB, Lo R, Beek FJA, Prokop M. (2009) Grading of carotid artery stenosis with multidetector-row CT angiography: visual estimation or caliper measurements? European Radiology 19(12): Rutten A, Isgum I, Prokop M. (2008) Coronary calcification: effect of small variation of scan starting position on Agatston, volume, and mass scores. Radiology 246(1): McKinney A, Casey SO, Teksam M, Lucato LT, Smith M, Truwit CL, Kieffer S. (2005) Carotid bifurcation and correlation with percent stenosis of the internal carotid artery on CT angiography. Neuroradiology 47:1-9 Personal Information Nikola Gotovac was also affiliated to Image sciences institute, University medical center Utrecht, The Netherlands, during making of this poster. Mathias Prokop was also affiliated with Department of radiology, University medical center Utrecht, The Netherlands, during making this poster. All images in this poster are made at University medical center Utrecht, The Netherlands, graphs are made by N. Gotovac. Page 8 of 8