In-hospital outcomes following an acute coronary syndrome in patients with recent cannabis use.

Background: The prevalence and short-term cardiovascular consequences of recent cannabis use in patients admitted to an intensive cardiac care unit for acute coronary syndrome is not well established.

Aims: To assess the prevalence of recent cannabis use detected by prospective systematic screening, and its prognostic value in predicting the occurrence of in-hospital major adverse events in consecutive patients with acute coronary syndrome.

Methods: From 07 to 22 April 2021, all consecutive patients admitted to an intensive cardiac care unit in 39 centres throughout France were studied prospectively.

Cellular structural and functional imaging of donor and pathological corneas with label-free dual-mode full-field optical coherence tomography.

In this study, a dual-mode full-field optical coherence tomography (FFOCT) was customized for label-free static and dynamic imaging of corneal tissues, including donor grafts and pathological specimens. Static images effectively depict relatively stable structures such as stroma, scar, and nerve fibers, while dynamic images highlight cells with active intracellular metabolism, specifically for corneal epithelial cells. The dual-mode images complementarily demonstrate the 3D microstructural features of the cornea and limbus.

Time-domain full-field optical coherence tomography (TD-FF-OCT) in ophthalmic imaging.

Ocular imaging plays an irreplaceable role in the evaluation of eye diseases. Developing cellular-resolution ophthalmic imaging technique for more accurate and effective diagnosis and pathogenesis analysis of ocular diseases is a hot topic in the cross-cutting areas of ophthalmology and imaging. Currently, ocular imaging with traditional optical coherence tomography (OCT) is limited in lateral resolution and thus can hardly resolve cellular structures.

Optical phase modulation by natural eye movements: application to time-domain FF-OCT image retrieval.

Eye movements are commonly seen as an obstacle to high-resolution ophthalmic imaging. In this context we study the natural axial movements of the in vivo human eye and show that they can be used to modulate the optical phase and retrieve tomographic images via time-domain full-field optical coherence tomography (TD-FF-OCT). This approach opens a path to a simplified ophthalmic TD-FF-OCT device, operating without the usual piezo motor-camera synchronization.

Distortion matrix concept for deep optical imaging in scattering media.

In optical imaging, light propagation is affected by the inhomogeneities of the medium. Sample-induced aberrations and multiple scattering can strongly degrade the image resolution and contrast. On the basis of a dynamic correction of the incident and/or reflected wavefronts, adaptive optics has been used to compensate for those aberrations.

Real-time non-contact cellular imaging and angiography of human cornea and limbus with common-path full-field/SD OCT.

In today's clinics, a cell-resolution view of the cornea can be achieved only with a confocal microscope (IVCM) in contact with the eye. Here, we present a common-path full-field/spectral-domain OCT microscope (FF/SD OCT), which enables cell-detail imaging of the entire ocular surface in humans (central and peripheral cornea, limbus, sclera, tear film) without contact and in real-time. Real-time performance is achieved through rapid axial eye tracking and simultaneous defocusing correction.

The role of prefrontal cortex in a moral judgment task using functional near-infrared spectroscopy.

Background: Understanding the neural basis of moral judgment (MJ) and human decision-making has been the subject of numerous studies because of their impact on daily life activities and social norms. Here, we aimed to investigate the neural process of MJ using functional near-infrared spectroscopy (fNIRS), a noninvasive, portable, and affordable neuroimaging modality.

Methods: We examined prefrontal cortex (PFC) activation in 33 healthy participants engaging in MJ exercises.

high resolution human corneal imaging using full-field optical coherence tomography.

We present the first full-field optical coherence tomography (FFOCT) device capable of imaging of the human cornea. We obtained images of the epithelial structures, Bowman's layer, sub-basal nerve plexus (SNP), anterior and posterior stromal keratocytes, stromal nerves, Descemet's membrane and endothelial cells with visible nuclei. Images were acquired with a high lateral resolution of 1.

Fast subsurface fingerprint imaging with full-field optical coherence tomography system equipped with a silicon camera.

Images recorded below the surface of a finger can have more details and be of higher quality than the conventional surface fingerprint images. This is particularly true when the quality of the surface fingerprints is compromised by, for example, moisture or surface damage. However, there is an unmet need for an inexpensive fingerprint sensor that is able to acquire high-quality images deep below the surface in short time.

coherence microscopy [Invited].

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: 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 coherent microscopy and show that endogenous or exogenous contrasts can add valuable information to the standard morphological image.

Utilization of interferometric light microscopy for the rapid analysis of virus abundance in a river.

There is a constant need for direct counting of biotic nanoparticles such as viruses to unravel river functioning. We used, for the first time in freshwater, a new method based on interferometry differentiating viruses from other particles such as membrane vesicles. In the French Marne River, viruses represented between 42 and 72% of the particles.

Intracellular dynamics measurements with full field optical coherence tomography suggest hindering effect of actomyosin contractility on organelle transport.

Intracellular motion can be quantitatively monitored in tissues using coherence-gated microscopic techniques. With full-field optical coherence tomography (FFOCT), the use of high numerical aperture microscope objectives provides a high resolution mapping of intracellular dynamics that are probed with subwavelength sensitivity. In the upper temporal bandwidth that we have used (1-6 Hz) the main contribution to the dynamic signal arises from the overall dynamical, optically heterogeneous cytoplasm.

Smart optical coherence tomography for ultra-deep imaging through highly scattering media.

Multiple scattering of waves in disordered media is a nightmare whether it is for detection or imaging purposes. So far, the best approach to get rid of multiple scattering is optical coherence tomography. This basically combines confocal microscopy and coherence time gating to discriminate ballistic photons from a predominant multiple scattering background.

Adaptive optics full-field optical coherence tomography.

We describe a simple and compact full-field optical coherence tomography (FFOCT) setup coupled to a transmissive liquid crystal spatial light modulator (LCSLM) to induce or correct aberrations. To reduce the system complexity, strict pupil conjugation was abandoned because low-order aberrations are often dominant. We experimentally confirmed a recent theoretical and experimental demonstration that the image resolution was almost insensitive to aberrations that mostly induce a reduction of the signal level.

Full-field spatially incoherent illumination interferometry: a spatial resolution almost insensitive to aberrations.

We show that with spatially incoherent illumination, the point spread function (PSF) width/spatial resolution of an imaging interferometer like that used in full-field optical coherence tomography (OCT) is almost insensitive to aberrations. In these systems, aberrations mostly induce a reduction of the signal level that leads to a loss of the signal-to-noise ratio without broadening the system PSF. This is demonstrated by comparison with traditional scanning OCT and wide-field OCT with spatially coherent illuminations.

Dynamic full field optical coherence tomography: subcellular metabolic contrast revealed in tissues by interferometric signals temporal analysis.

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.

Fingerprint imaging from the inside of a finger with full-field optical coherence tomography.

Imaging below fingertip surface might be a useful alternative to the traditional fingerprint sensing since the internal finger features are more reliable than the external ones. One of the most promising subsurface imaging technique is optical coherence tomography (OCT), which, however, has to acquire 3-D data even when a single en face image is required. This makes OCT inherently slow for en face imaging and produce unnecessary large data sets.

Dark-field full-field optical coherence tomography.

Full-field optical coherence tomography (FF-OCT) provides en face images from deep in the tissue with high spatial resolution. Specular reflections, however, may reduce image contrast as it can be much stronger than the backscattered signal from a specimen. To this end, we demonstrate dark-field FF-OCT (d-FF-OCT) that can block specular reflections by the help of an opaque disk in the pupil-conjugated plane.

Retrieving time-dependent Green's functions in optics with low-coherence interferometry.

We report on the passive measurement of time-dependent Green's functions in the optical frequency domain with low-coherence interferometry. Inspired by previous studies in acoustics and seismology, we show how the correlations of a broadband and incoherent wave field can directly yield the Green's functions between scatterers of a complex medium. Both the ballistic and multiple scattering components of the Green's function are retrieved.

Early invasive strategy in high-risk acute coronary syndrome without ST-segment elevation. The Sisca randomized trial.

Background: The optimal therapeutic strategy for patients with high-risk acute coronary syndrome without ST-segment elevation (NSTE-ACS) remains unclear.

Objective: Our aim was to compare the effectiveness of an early invasive strategy and a delayed invasive strategy in the management of high-risk NSTE-ACS patients.

Methods: This randomized clinical trial in a primarily pre-hospital setting enrolled patients with chest pain, electrocardiographic criteria for an NSTE-ACS, and at least one criterion of severity (ESC criterion or TIMI score >5).

Detection of plasmonic nanoparticles with full field-OCT: optical and photothermal detection.

Detecting the signal backscattered by nanoparticles immersed in highly scattering media such as biological tissue remains a challenge. In this article we report on the use of Full Field OCT (FF-OCT) to slice in depth in phantoms and in tissues in order a) to selectively observe the particles through the backscattered light at suitable wavelengths, and b) to detect the effects of the time-dependent response to full field optical heating through the strong absorption cross-section of these plasmonic nanoparticles. The analysis of the thermal wave behavior leads to the localization of the heat sources even when FF-OCT signals cannot reach the heated area.