Intravascular polarization sensitive optical coherence tomography
Event details
| Date | 28.03.2014 |
| Hour | 12:00 |
| Speaker | Dr. Martin Villiger of the Wellman Center for Photomedicine, Massachusetts and the Harvard Medical School |
| Location | |
| Category | Conferences - Seminars |
In addition to structural imaging, polarization sensitive optical coherence tomography (PS-OCT) quantifies the polarization of the light scattered by a sample. Many tissues and molecules intrinsically alter the polarization state of the probing light, and detecting these polarization signatures can offer valuable insight for diagnostic purposes and provides additional imaging contrast. PS-OCT measurements through a catheter probe have been limited, however, by the presence of system induced polarization distortions. We have developed a reconstruction strategy based on the Mueller-Stokes formalism that mitigates the resulting artifacts and provides a measure of tissue birefringence as well as depolarization. Although OCT is a coherent imaging technique that by definition can only measure fully polarized light, I will evidence how spatial averaging is akin to making the imaging process partially coherent and enables the measure of depolarization effects.
We have performed catheter-based PS-OCT in human coronary arteries, both in vivo and in cadaveric hearts, for the assessment of atherosclerosis. The measure of birefringence provides an estimation of the collagen content in the vessel wall and depolarization was found to be indicative of lipid pools and foam cells. Plaques that rupture and potentially cause myocardial infarction typically have a thin fibrous cap devoid of collagen, overlaying a large lipid pool. PS-OCT might help to identify these plaques and determine their vulnerability. Collagen content is also modulated under the influence of inflammation and medication, and PS-OCT could dramatically improve drug evaluation studies by providing early time points of drug efficacy.
Our reconstruction strategy reveals polarization features that complement well the structural OCT signal and offers a quantitative characterization of tissue. Beyond intracoronary imaging, this additional contrast shows great promise in several applications with clinical relevance.
We have performed catheter-based PS-OCT in human coronary arteries, both in vivo and in cadaveric hearts, for the assessment of atherosclerosis. The measure of birefringence provides an estimation of the collagen content in the vessel wall and depolarization was found to be indicative of lipid pools and foam cells. Plaques that rupture and potentially cause myocardial infarction typically have a thin fibrous cap devoid of collagen, overlaying a large lipid pool. PS-OCT might help to identify these plaques and determine their vulnerability. Collagen content is also modulated under the influence of inflammation and medication, and PS-OCT could dramatically improve drug evaluation studies by providing early time points of drug efficacy.
Our reconstruction strategy reveals polarization features that complement well the structural OCT signal and offers a quantitative characterization of tissue. Beyond intracoronary imaging, this additional contrast shows great promise in several applications with clinical relevance.
Practical information
- General public
- Free
Organizer
- Prof. Theo Lasser
Contact
- Fabienne Ubezio