Investigations of the intravascular backscattering distribution of light in optical coherence tomography

The inhomogeneous backscattering distribution of low-coherent light in blood vessels, which appears as waisted double fan-shaped intensity pattern, is investigated in an in vivo mouse model and flow phantom measurements using high resolution spectral domain optical coherence tomography in the 1.3 μm wavelength region. Based on a predicted orientation of the red blood cells towards laminar flow, an angular modulation of the corresponding backscattering crosssection inside the vessels is assumed. In combination with the signal attenuation in depth by absorption and scattering, a simple model of the intravascular intensity modulation is derived. The suitability of the model is demonstrated exemplarily at the saphenous artery of the mouse during different states of the heart cycle as well as at phantom measurements with well known flow characteristics. The obtained data and the predicted model show good correspondence to each other which leads to the conclusion that the red blood cell orientation seems to be the reason for the observed intensity distribution inside the blood vessels. Therefore, the analysis of the intravascular intensity pattern might be useful for the evaluation of flow characteristics. Additional investigations of the precise angular backscattering of the complex shaped red blood cells are necessary for further model refinement.

[1]  Edmund Koch,et al.  Transverse motion as a source of noise and reduced correlation of the Doppler phase shift in spectral domain OCT. , 2009, Optics express.

[2]  Edmund Koch,et al.  In-vivo Fourier domain optical coherence tomography as a new tool for investigation of vasodynamics in the mouse model. , 2009, Journal of biomedical optics.

[3]  Meng-Tsan Tsai,et al.  Measurement of the hemoglobin oxygen saturation level with spectroscopic spectral-domain optical coherence tomography. , 2008, Optics letters.

[4]  Edmund Koch,et al.  Analysis of in vitro and in vivo bidirectional flow velocities by phase-resolved , 2009 .

[5]  Edmund Koch,et al.  Simultaneous dual-band optical coherence tomography in the spectral domain for high resolution in vivo imaging. , 2009, Optics express.

[6]  Edmund Koch,et al.  Effects of axial, transverse, and oblique sample motion in FD OCT in systems with global or rolling shutter line detector. , 2008, Journal of the Optical Society of America. A, Optics, image science, and vision.

[7]  Edmund Koch,et al.  Time-resolved blood flow measurement in the in vivo mouse model by optical frequency domain imaging , 2009, European Conference on Biomedical Optics.

[8]  T W Secomb,et al.  Red blood cells and other nonspherical capsules in shear flow: oscillatory dynamics and the tank-treading-to-tumbling transition. , 2007, Physical review letters.

[9]  M. Wojtkowski,et al.  Flow velocity estimation using joint Spectral and Time domain Optical Coherence Tomography. , 2008, Optics express.

[10]  S H Yun,et al.  Motion artifacts in optical coherence tomography with frequency-domain ranging. , 2004, Optics express.

[11]  Dirk J. Faber,et al.  Toward assessment of blood oxygen saturation by spectroscopic optical coherence tomography. , 2005 .