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- Johansson, Elias, et al.
(author)
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Carotid near-occlusion can be identified with ultrasound by low flow velocity distal to the stenosis
- 2019
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In: Acta Radiologica. - : Sage Publications. - 0284-1851 .- 1600-0455. ; 60:3, s. 396-404
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Journal article (peer-reviewed)abstract
- Background: Most carotid near-occlusions are indistinguishable from conventional >= 50% stenosis on ultrasound, demonstrating high peak systolic velocity (PSV) in the stenosis. Purpose To study whether the velocity distal to the stenosis can separate high PSV near-occlusion from conventional >= 50% stenosis.Material and Methods: We included patients with >= 50% carotid stenosis with high PSV (>= 125 cm/s), examined with both computed tomography angiography (CTA) and ultrasound within 30 days, and a distal velocity measurement was performed. Based on CTA, cases were divided into three groups: conventional stenosis; near-occlusion without full collapse (NwoC; normal-appearing albeit small distal artery); and near-occlusion with full collapse (NwC; threadlike distal artery). Distal Doppler ultrasound flow velocities were compared between these groups.Results: Sixty patients were included: 33 patients with conventional stenosis; 20 patients with NwoC; and seven patients with NwC. Mean distal PSV was 93, 63, and 21 cm/s (P < 0.001) and mean distal end-diastolic velocity was 30, 24, and 5 cm/s (P < 0.001), respectively. A distal PSV < 50 cm/s was 63% sensitive and 94% specific for separating both types of near-occlusion from conventional stenosis.Conclusion: In high PSV carotid stenoses, the distal velocity was lower in near-occlusions than conventional carotid stenosis. Distal velocities warrant further investigation in diagnostic studies.
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| 2. |
- Khangure, Simon R., et al.
(author)
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Carotid near-occlusion frequently has high peak systolic velocity on Doppler ultrasound
- 2018
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In: Neuroradiology. - : Springer. - 0028-3940 .- 1432-1920. ; 60:1, s. 17-25
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Journal article (peer-reviewed)abstract
- Purpose: Carotid near-occlusion is a tight atherosclerotic stenosis of the internal carotid artery (ICA) resulting in decrease in diameter of the vessel lumen distal to the stenosis. Near-occlusions can be classified as with or without full collapse, and may have high peak systolic velocity (PSV) across the stenosis, mimicking conventional > 50% carotid artery stenosis. We aimed to determine how frequently near-occlusions have high PSV in the stenosis and determine how accurately carotid Doppler ultrasound can distinguish high-velocity near-occlusion from conventional stenosis.Methods: Included patients had near-occlusion or conventional stenosis with carotid ultrasound and CT angiogram (CTA) performed within 30 days of each other. CTA examinations were analyzed by two blinded expert readers. Velocities in the internal and common carotid arteries were recorded. Mean velocity, pulsatility index, and ratios were calculated, giving 12 Doppler parameters for analysis.Results: Of 136 patients, 82 had conventional stenosis and 54 had near-occlusion on CTA. Of near-occlusions, 40 (74%) had high PSV (≥ 125 cm/s) across the stenosis. Ten Doppler parameters significantly differed between conventional stenosis and high-velocity near-occlusion groups. However, no parameter was highly sensitive and specific to separate the groups.Conclusion: Near-occlusions frequently have high PSV across the stenosis, particularly those without full collapse. Carotid Doppler ultrasound does not seem able to distinguish conventional stenosis from high-velocity near-occlusion. These findings question the use of ultrasound alone for preoperative imaging evaluation.
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