September 2013
Review Articles

Vascular Wall Imaging of Vulnerable Atherosclerotic Carotid Plaques: Current State of the Art and Potential Future of Endovascular Optical Coherence Tomography

Victor X.D. Yang

Victor X.D. Yang

The current standard of care for the assessment of carotid plaques has been the use of ultrasonography, MR imaging, and CT to identify key features of atherosclerosis. Fundamental markers such as intimal morphology, presence of macrophages, and lipid content in the plaque are attributed to the classification of the lesion, as well as assessment of stroke risk. A challenge for the aforementioned imaging modalities is that some of these characteristics are often below their resolution limit. It has been shown that optical coherence tomography (OCT) has the capability of resolving the important markers in the coronary vessels. The application of this optical imaging modality has not fully matured for imaging of carotid arteries.

As a result, we are exploring the various potential techniques and applications in preclinical animal carotid models, including nonocclusive saline-based flushing for optimal OCT imaging of vessel wall,1 flow velocity,2 and stent visualization.3  Such techniques reduce contrast load and radiation exposure to patients because optical imaging, as opposed to x-ray based methods, penetrates through saline and the vessel wall to

form images without Omnipaque. The 2.7F OCT catheter, emitting visible red light, as seen in the Figure (A), and broad spectrum infrared light to allow 3D imaging of carotid stent (B).

yang.fig

Click image to view larger version

As more groups start to utilize this novel high-resolution endovascular imaging technology for carotid diseases, we anticipate more preclinical and clinical trials will be required to perfect the technique and analyze the risk-benefit balance, as the pendulum swings between noninvasive modalities and angiography.

References

  1. Cheng KHY, Sun C, Vuong B, et al. Endovascular optical coherence tomography intensity kurtosis: visualization of vasa vasorum in porcine carotid artery. Biomed Opt Express 2012;3:388–99. doi: 10.1364/BOE.3.000388
  2. Sun C, Nolte F, Cheng KHY, et al. In vivo feasibility of endovascular Doppler optical coherence tomography. Biomed Opt Express 2012;3:2600–10. doi: 10.1364/BOE.3.002600
  3. Cheng KHY, Sun C, Cruz JP, et al. Comprehensive data visualization for high resolution endovascular carotid arterial wall imaging. J Biomed Opt 2012 May 4 [Epub ahead of print]. doi: 10.1117/1.JBO.17.5.056003

 

Read this article at AJNR.org . . .