Suvi Maaria Koskinen1,2, Heli Silvennoinen3, Petra Ijäs4,5, Krista Nuotio4,5, Leena Valanne3, Perttu J Lindsberg4,5, Lauri Soinne4. 1. Clinicum, Department of Neurosciences, University of Helsinki, Haartmaninkatu 8, Biomedicum 1 Helsinki, Room B412b, PO Box 700, 00029 HUS, Helsinki, Finland. suvi.koskinen@helsinki.fi. 2. HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland. suvi.koskinen@helsinki.fi. 3. HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland. 4. Neurology, Clinical Neurosciences, University of Helsinki and Helsinki University Hospital, Helsinki, Finland. 5. Molecular Neurology, Research Programs Unit, University of Helsinki, Helsinki, Finland.
Abstract
INTRODUCTION: Near-occlusion of the internal carotid artery (ICA) is a significant luminal diameter (LD) reduction beyond a tight atherosclerotic carotid stenosis (CS). Recognition of even subtle near-occlusions is essential to prevent underestimation of the stenosis degree. Our goal was to investigate the prevalence of near-occlusion among CS patients using a single standard criterion to facilitate its recognition, even when distal ICA LD reduction is not visually evident in computed tomography angiography (CTA). METHODS: We analysed carotid artery CTAs of 467 patients with moderate-to-severe CS scheduled for endarterectomy. We performed measurements of the bilateral distal ICA LDs from thin axial source images and utilized a 1.0 mm intra-individual side-to-side distal ICA LD difference to distinguish near-occlusions, based on a previous study, aware of the vagaries of measurement. For analysis stratification, we excluded cases with significant carotid pathology affecting LD measurements. RESULTS: We discovered 126 near-occlusions fulfilling our criterion of ipsilateral near-occlusion: the mean LD side-to-side difference (mm) with 95% confidence interval being 1.8 (1.6, 1.9) and a standard deviation of 0.8 mm. Among the 233 cases not meeting our near-occlusion criterion, we found 140 moderate (50-69%) and 93 severe (70-99%) ipsilateral stenoses. CONCLUSION: The utilization of 1.0 mm cut-off value for the intra-individual distal ICA LD side-to-side difference to distinguish atherosclerotic ICA near-occlusion leads to a relatively high incidence of near-occlusion. In CTA, recently suggested to be used for near-occlusion diagnosis, a discriminatory 1.0 mm cut-off value could function as a pragmatic tool to enhance the detection of even subtle near-occlusions.
INTRODUCTION: Near-occlusion of the internal carotid artery (ICA) is a significant luminal diameter (LD) reduction beyond a tight atherosclerotic carotid stenosis (CS). Recognition of even subtle near-occlusions is essential to prevent underestimation of the stenosis degree. Our goal was to investigate the prevalence of near-occlusion among CS patients using a single standard criterion to facilitate its recognition, even when distal ICA LD reduction is not visually evident in computed tomography angiography (CTA). METHODS: We analysed carotid artery CTAs of 467 patients with moderate-to-severe CS scheduled for endarterectomy. We performed measurements of the bilateral distal ICA LDs from thin axial source images and utilized a 1.0 mm intra-individual side-to-side distal ICA LD difference to distinguish near-occlusions, based on a previous study, aware of the vagaries of measurement. For analysis stratification, we excluded cases with significant carotid pathology affecting LD measurements. RESULTS: We discovered 126 near-occlusions fulfilling our criterion of ipsilateral near-occlusion: the mean LD side-to-side difference (mm) with 95% confidence interval being 1.8 (1.6, 1.9) and a standard deviation of 0.8 mm. Among the 233 cases not meeting our near-occlusion criterion, we found 140 moderate (50-69%) and 93 severe (70-99%) ipsilateral stenoses. CONCLUSION: The utilization of 1.0 mm cut-off value for the intra-individual distal ICA LD side-to-side difference to distinguish atherosclerotic ICA near-occlusion leads to a relatively high incidence of near-occlusion. In CTA, recently suggested to be used for near-occlusion diagnosis, a discriminatory 1.0 mm cut-off value could function as a pragmatic tool to enhance the detection of even subtle near-occlusions.
Authors: Allan J Fox; Michael Eliasziw; Peter M Rothwell; Matthias H Schmidt; Charles P Warlow; Henry J M Barnett Journal: AJNR Am J Neuroradiol Date: 2005-09 Impact factor: 3.825
Authors: H J M Barnett; D W Taylor; R B Haynes; D L Sackett; S J Peerless; G G Ferguson; A J Fox; R N Rankin; V C Hachinski; D O Wiebers; M Eliasziw Journal: N Engl J Med Date: 1991-08-15 Impact factor: 91.245
Authors: Debbie L Bennett; Leena M Hamberg; Bing Wang; Joshua A Hirsch; R Gilberto González; George J Hunter Journal: PLoS One Date: 2014-06-06 Impact factor: 3.240