We developed a new endogenous approach to reveal subcellular metabolic contrast in fresh ex vivo tissues taking advantage of the time dependence of the full field optical coherence tomography interferometric signals. This method reveals signals linked with local activity of the endogenous scattering elements which can reveal cells where other OCT-based techniques fail or need exogenous contrast agents. We benefit from the micrometric transverse resolution of full field OCT to image intracellular features. We used this time dependence to identify different dynamics at the millisecond scale on a wide range of organs in normal or pathological conditions.

Full-field optical coherence tomography (FF-OCT) is a variant of OCT that is able to register 2D en face views of scattering samples at a given depth. Thanks to its superior resolution, it can quickly reveal information similar to histology without the need to physically section the sample. Sensitivity and specificity levels of diagnosis performed with FF-OCT are 80% to 95% of the equivalent histological diagnosis performances and could therefore benefit from improvement. Therefore, multimodal systems have been designed to increase the diagnostic performance of FF-OCT. In this paper, we will discuss which contrasts can be measured with such multimodal systems in the context of ex vivo biological tissue examination. We will particularly emphasize three multimodal combinations to measure the tissue mechanics, dynamics, and molecular content respectively.

En face coherence microscopy or flying spot or full field optical coherence tomography or microscopy (FF-OCT/FF-OCM) belongs to the OCT family because the sectioning ability is mostly linked to the source coherence length. In this article we will focus our attention on the advantages and the drawbacks of the following approaches: en face versus B scan tomography in terms of resolution, coherent versus incoherent illumination and influence of aberrations, and scanning versus full field imaging. We then show some examples to illustrate the diverse applications of en face coherent microscopy and show that endogenous or exogenous contrasts can add valuable information to the standard morphological image. To conclude we discuss a few domains that appear promising for future development of en face coherence microscopy. tomography with a Linnik microscope," Appl. Opt. 41, 805-812 (2002). 6. L. Vabre, A. Dubois, and A. C. Boccara, "Thermal-light full-field optical coherence tomography," Opt. Lett. 27(7), 530-532 (2002). 7. Handbook of Full-Field Optical Coherence Microscopy: Technology and Applications; Arnaud Dubois editor.Pan Stanford 2016. 8. M. Akiba, K. P. Chan, and N. Tanno, "Full-field optical coherence tomography by two-dimensional heterodyne detection with a pair of CCD cameras," Opt. Lett. 28(10), 816-818 (2003). 9. L. Yu and M. Kim, "Full-color three-dimensional microscopy by wide-field optical coherence tomography," Opt.Express 12(26), 6632-6641 (2004 Hüttmann, "In-vivo retinal imaging with off-axis full-field time-domain optical coherence tomography," Opt. Lett. 41(21), 4987-4990 (2016). 44. M. Villiger, C. Pache, and T. Lasser, "Dark-field optical coherence microscopy," Opt. Lett. 35(20), 3489-3491 (2010). 45. E. Auksorius and A. C. Boccara, "Dark-field full-field optical coherence tomography," Opt. Lett. 40(14), 3272-3275 (2015 4948-4956 (2008). 107. C.-E. Leroux, F. Bertillot, O. Thouvenin, and A.-C. Boccara, "Intracellular dynamics measurements with full field optical coherence tomography suggest hindering effect of actomyosin contractility on organelle transport," Biomed. Opt. Express 7(11), 4501-4513 (2016). 108. J. Schmitt, "OCT elastography: imaging microscopic deformation and strain of tissue," Opt. Express 3(6), 199-211 (1998

No abstract

No abstract

No abstract

Cells shape or density is an important marker of tissues pathology. However, individual cells are difficult to observe in thick tissues frequently presenting highly scattering structures such as collagen fibers. Endogenous techniques struggle to image cells in these conditions. Moreover, exogenous contrast agents like dyes, fluorophores or nanoparticles cannot always be used, especially if non-invasive imaging is required.View presentation recording on the SPIE Digital Library: http://dx.

No abstract