Rapid and high-resolution imaging of human liver specimens by full-field optical coherence tomography

Abstract

We report rapid and high-resolution tomographic en face imaging of human liver specimens by full-field optical coherence tomography (FF-OCT). First, the arrangement of the FF-OCT system was described and the performance of the system was measured. The measured axial and lateral resolutions of the system are 0.8 and 0.9 μm, respectively. The system has a sensitivity of ∼60 dB and can achieve an imaging rate of 7 fps and a penetration depth of ∼80 μm. The histological structures of normal liver can be seen clearly in the en face tomographic images, including central veins, cords of hepatocytes separated by sinusoidal spaces, and portal area (portal vein, the hepatic arteriole, and the bile duct). A wide variety of histological subtypes of hepatocellular carcinoma was observed in en face tomographic images, revealing notable cancerous features, including the nuclear atypia (enlarged convoluted nuclei), the polygonal tumor cells with obvious resemblance to hepatocytes with enlarged nuclei. In addition, thicker fibrous bands, which make the cytoplasmic plump vesicular nuclei indistinct, were also seen in the images. Finally, comparison between the portal vein in a normal specimen versus that seen in the rare type of cholangiocarcinoma was made. The results show that the cholangiocarcinoma presents with a blurred pattern of portal vein in the lateral direction and an aggregated distribution in the axial direction; the surrounding sinusoidal spaces and nuclei of cholangiocarcinoma are absent. The findings in this work may be used as additional signs of liver cancer or cholangiocarcinoma, demonstrating capacity of FFOCT device for early cancer diagnosis and many other tumor-related studies in biopsy.

Liver tissue classification of en face images by fractal dimension‐based support vector machine

“…The en face structural tomographic images can be obtained after the acquisition of a series of interferograms with the algorithm described in Ref. . The axial and lateral resolution of FF‐OCT system are aroud 1.4 and 0.8 μm, which has been published .…”

Differences between time domain and Fourier domain optical coherence tomography in imaging tissues

“…For micron FDOCT and full field optical coherence tomography (FFOCT) (Dubois et al, 2002;Federici & Dubois, 2015;Gao, 2015;Zhu et al, 2015), the random properties of tissue should be taken into account. In this case, because the depth resolution is high, the light scattered from the correlated structures is measured.…”

Image contrast reduction mechanism in full‐field optical coherence tomography

“…Note that both the light scattering spectroscopy measurements and the spatial spectrum analysis of en‐face tomographic images of normal and cancerous human tissues showed that among three parameters that characterize tissue structure (see Eq. ), the values of parameter m of the dysplastic tissues are significantly smaller than those from normal sites (Gao & Zhu, ; Hunter et al ., ).…”

“…Figure 2 shows the en-face images of the human liver in normal and cancers states (see Supplementary Description of the FFOCT system specifications). The polygonal shaped cells can be seen clearly in the image of the normal liver Figure 2(A) whereas in the liver cancer tissue, the regular structures of cells cannot be seen and the microstructures of hematomas is of almost uniform distribution (Zhu et al, 2015b). Optical schematic of the Linnik interference microscope-based FFOCT.…”

“…Figure 6 depicts enface tomographic images of unprocessed human liver at the depths beneath the surface without and with compensation of the signal decay induced by the multiple scattering process (see Eq. (18)) (Zhu et al, 2015b). Figure 6(A) is en-face tomographic image at the depth of ß35 μm beneath the surface of the unstained fresh liver tissue showing detailed components of basic liver lobules with portal area.…”