Vector Concentration used for Stenosis Assessment in the Carotid Artery before and after Carotid Stenting

Andreas Hjelm Brandt, Tin-Quoc Nguyen, Henrik Gutte, Markus Holtmannspötter, Ramin Moshavegh, Jørgen Arendt Jensen, Michael Bachmann Nielsen, Kristoffer Lindskov Hansen

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Angiography of carotid stenosis is the preferred method for stenosis assessment, but the method is invasive and ionizing. The ultrasound technique Vector Flow Imaging (VFI) is proposed as a noninvasive and nonionizing alternative for stenosis assessment. Vessel stenosis and flow complexity are associated, and VFI can measure flow complexity with Vector Concentration (VC). VC goes towards 1 for laminar flow and 0 for complex flow. In this preliminary study, 5 patients treated with carotid stent for carotid artery stenosis were examined with VFI to evaluate if VC estimations were comparable with the corresponding digital substraction angiography (DSA) calculated stenosis degree percentage. VFI was obtained with a bk5000 ultrasound scanner and an 8L2 linear transducer with a frequency range from 2-8 MHz (BK Medical, Herlev, Denmark), while angiography data were obtained with Siemens Artis Q (Siemens, Erlangen, Germany). The flow in the stenosis was evaluated with VC as a mean over 100 frames with a frame rate of 30 Hz. VC of the stenotic carotid artery was low for all patients before stenting with a mean of 0.59 (SD:0.07), while mean VC increased to 0.97 (SD:0.02) after stenting (p=0.016). Mean DSA stenosis degree percentage was 82% (SD:9%) before stenting and was reduced to 11% (SD:6%) after stenting (p=0.001). Correlation coefficient between VC and DSA stenosis degree was strong 0.97. This is the first preliminary study that shows VFI can be used to evaluate stent treatment of carotid stenosis. The results indicate that VC is a useful parameter for flow complexity assessment, and that VC and stenosis degree are comparable for patients with carotid stenosis.
Original languageEnglish
Title of host publicationProceedings of the 2019 IEEE International Ultrasonics Symposium
Publication date2019
Article numberMoPoS-03.4
ISBN (Electronic)978-1-7281-4596-9
Publication statusPublished - 2019
Event2019 IEEE International Ultrasonics Symposium - SEC Glasgow, Glasgow, United Kingdom
Duration: 6 Oct 20199 Oct 2019


Conference2019 IEEE International Ultrasonics Symposium
LocationSEC Glasgow
CountryUnited Kingdom
Internet address


  • Carotid Stenosis
  • Vector Flow Imaging
  • Vector Concentration
  • Digital Subtraction Angiography

Cite this

Brandt, A. H., Nguyen, T-Q., Gutte, H., Holtmannspötter, M., Moshavegh, R., Jensen, J. A., Nielsen, M. B., & Lindskov Hansen, K. (2019). Vector Concentration used for Stenosis Assessment in the Carotid Artery before and after Carotid Stenting. In Proceedings of the 2019 IEEE International Ultrasonics Symposium (pp. 348-351). [MoPoS-03.4] IEEE.