Mirau-based line-field confocal optical coherence tomography for three-dimensional high-resolution skin imaging

Weikai Xue (1) , Jonas Ogien (2) , Pavel Bulkin (3) , Anne-Lise Coutrot (1) , Arnaud Dubois (1)

1 Laboratoire Charles Fabry / Biophotonique
2 DAMAE - DAMAE Medical
3 LPICM - Laboratoire de physique des interfaces et des couches minces [Palaiseau]

Significance: Line-field confocal optical coherence tomography (LC-OCT) is a recently introduced high-resolution imaging modality based on a combination of low-coherence optical interferometry and reflectance confocal optical microscopy with line illumination and line detection. Capable of producing three-dimensional (3D) images of the skin with cellular resolution, in vivo, LC-OCT has been mainly applied in dermatology and dermo-cosmetology. The LC-OCT devices capable of acquiring 3D images reported so far are based on a Linnik interferometer using two identical microscope objectives. In this configuration, LC-OCT cannot be designed to be a very compact and light device, and the image acquisition speed is limited. Aim: The objective of this work was to develop a more compact and lighter LC-OCT device that is capable of acquiring images faster without significant degradation of the resolution and with optimized detection sensitivity. Approach: We developed an LC-OCT device based on a Mirau interferometer using a single objective. Dynamic adjustment of the camera frequency during the depth scan is implemented, using a faster camera and a more powerful light source. The reflectivity of the beam-splitter in the Mirau interferometer was optimized to maximize the detection sensitivity. A galvanometer scanner was incorporated into the device for scanning the illumination line laterally. A stack of adjacent B-scans, constituting a 3D image, can thus be acquired. Results: The device is able to acquire and display B-scans at 17 fps. 3D images with a quasiisotropic resolution of ∼1.5 μm (1.3, 1.9, and 1.1 μm in the x; y, and z directions, respectively) over a field of 940 μm × 600 μm × 350 μm (x × y × z) can be obtained. 3D imaging of human skin at cellular resolution, in vivo, is reported. Conclusions: The acquisition rate of the B-scans, at 17 fps, is unprecedented in LC-OCT. Compared with the conventional LC-OCT devices based on a Linnik interferometer, the reported Mirau-based LC-OCT device can acquire B-scans ∼2 times faster. With potential advantages in terms of compactness and weight, a Mirau-based device could easily be integrated into a smaller and lighter handheld probe for use by dermatologists in their daily medical practice.

Mots clés: optical coherence tomography optical imaging confocal microscopy dermatology skin cancer; optical coherence tomography; optical imaging; confocal microscopy; dermatology; skin cancer

Domaines: Physique [physics]

Weikai Xue, Jonas Ogien, Pavel Bulkin, Anne-Lise Coutrot, Arnaud Dubois. Mirau-based line-field confocal optical coherence tomography for three-dimensional high-resolution skin imaging. Journal of Biomedical Optics, 2022, ⟨10.1117/1.JBO.27.8.086002]⟩. ⟨hal-04282168⟩