Hongki Yoo

Abstract Confocal microscopy uses a confocal aperture in front of a detector to eliminate out-of-focus blur, providing optical sectioning, high spatial resolution, and high contrast. It enables precise three-dimensional (3D) reconstruction of a sample surface. Using objective lenses with high numerical aperture and short wavelength illumination, confocal microscopy offers high spatial resolution in both lateral and axial directions in a non-destructive and non-contact manner. These qualities mak

The point spread function of an objective lens of a fluorescence confocal microscope was directly measured by imaging fluorescent beads. We analysed how the measurement of the point spread function was influenced by the diameter of the fluorescent beads and how the restoration technique with a deconvolution algorithm improved the measuring performance. Numerical and experimental results are presented for a typical point spread function and a zero-centred point spread function.

Optical coherence tomography (OCT) is a 3-dimensional high-resolution imaging modality based on an interferometry and is widely used in a large variety of medical fields. Spectroscopic OCT (S-OCT) is a signal-processing method that uses the raw interferograms generated by OCT to investigate depth-resolved spectroscopic profiles of a sample. The spectroscopic information provided by S-OCT can be used to enhance the contrast of OCT images and overcome the limitations of gray-scale OCT images that

<b>Rationale:</b> Atherosclerotic plaque is a chronic inflammatory disorder involving lipid accumulation within arterial walls. In particular, macrophages mediate plaque progression and rupture. While PPARγ agonist is known to have favorable pleiotropic effects on atherogenesis, its clinical application has been very limited due to undesirable systemic effects. We hypothesized that the specific delivery of a PPARγ agonist to inflamed plaques could reduce plaque burden and inflammation without sy

Coronary plaque destabilization involves alterations in microstructure and biochemical composition; however, no imaging approach allows such comprehensive characterization. Herein, the authors demonstrated a simultaneous microstructural and biochemical assessment of high-risk plaques in the coronary arteries in a beating heart using a fully integrated optical coherence tomography and fluorescence lifetime imaging (FLIm). It was found that plaque components such as lipids, macrophages, lipids+mac

Recent studies on endothelial dysfunction in relation to vascular diseases including atherosclerosis have highlighted the key contribution of the microenvironment of endothelial cells (ECs). By mimicking the microenvironment of early atherosclerotic lesions, here, we replicate the pathophysiological phenotype and function of ECs within microchannels. Considering the elevated deposition of fibronectin (FN) in early atherosclerotic plaques and the close correlation between the vascular stiffness a

We propose dual-detection confocal reflectance microscopy (DDCRM) for high-speed 3D surface profiling. In comparison with conventional confocal microscopy, DDCRM can realize surface profiling without axial scanning. DDCRM is composed of two point detectors, each with a pinhole of different size. The ratio of the axial response curves measured by the two detectors provides the relationship between the axial position of the sample and the ratio of the intensity signals. Furthermore, DDCRM has a no

This study confirms the use of confocal fluorescence microscopy technique to acquire rapid pathology results using optical sectioning, line scanning and focus tracking. We anticipate that the presented method will enable intraoperative histology and significantly reduce stress on patients undergoing surgery requiring repeated histology examinations.