Rainer A Leitgeb

Rainer A Leitgeb
Medical University of Vienna | MedUni Vienna · Center for Medical Physics and Biomedical Engineering

PhD

About

309
Publications
52,949
Reads
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12,003
Citations
Citations since 2016
108 Research Items
5095 Citations
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
Additional affiliations
January 2015 - present
Christian Doppler Laboratory of Innovative Optical Imaging and its Translation to Medicine
Position
  • Principal Investigator
October 2007 - present
Medizinische Universität Wien
Position
  • Professor (Associate)
October 2004 - September 2007
École Polytechnique Fédérale de Lausanne
Position
  • Professor

Publications

Publications (309)
Article
Full-text available
Optical angiography systems based on optical coherence tomography (OCT) require dense sampling in order to maintain good vascular contrast. We demonstrate a way to gain acquisition speed and spatial sampling by using spectral splitting with a swept source OCT system. This method splits the recorded spectra into two to several subspectra. Using cont...
Article
Full-text available
In the last 25 years, optical coherence tomography (OCT) has advanced to be one of the most innovative and most successful translational optical imaging techniques, achieving substantial economic impact as well as clinical acceptance. This is largely owing to the resolution improvements by a factor of 10 to the submicron regime and to the imaging s...
Article
Full-text available
Optical Coherence Tomography (OCT) has revolutionized ophthalmology. Since its introduction in the early 1990s it has continuously improved in terms of speed, resolution and sensitivity. The technique has also seen a variety of extensions aiming to assess functional aspects of the tissue in addition to morphology. One of these approaches is Doppler...
Article
Full-text available
This paper proposes a sub-aperture correlation based numerical phase correction method for interferometric full field imaging systems provided the complex object field information can be extracted. This method corrects for the wavefront aberration at the pupil/ Fourier transform plane without the need of any adaptive optics, spatial light modulator...
Article
Full-text available
We demonstrate noninvasive structural and microvascular contrast imaging of different human skin diseases in vivo using an intensity difference analysis of OCT tomograms. The high-speed swept source OCT system operates at 1310 nm with 220 kHz A-scan rate. It provides an extended focus by employing a Bessel beam. The studied lesions were two cases o...
Article
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Optical Coherence Tomography Angiography (OCTA), a functional extension of OCT, has the potential to replace most invasive fluorescein angiography (FA) exams in ophthalmology. So far, OCTA’s field of view is however still lacking behind fluorescence fundus photography techniques. This is problematic, because many retinal diseases manifest at an ear...
Article
Full-text available
Aim: To assess the detection rate of retinal neovascularisation (NV) in eyes with proliferative diabetic retinopathy (PDR) using widefield optical coherence tomography angiography (WF-OCTA) in comparison to ultrawidefield fluorescein angiography (UWF-FA). Methods: Single-capture 65°-WF-OCTA-imaging was performed in patients with NV at the disc or...
Article
Optical coherence tomography (OCT) is a non-contact method for imaging the topological and internal microstructure of samples in three dimensions. OCT can be configured as a conventional microscope, an ophthalmic scanner or endoscopes and small-diameter catheters for accessing internal biological organs. In this Primer, the principles underpinning...
Preprint
Full-text available
The automatic detection and localization of anatomical features in retinal imaging data are relevant for many aspects. In this work, we follow a data-centric approach to optimize classifier training for optic nerve head detection and localization in optical coherence tomography en face images of the retina. We examine the effect of domain knowledge...
Conference Paper
Full-text available
A fiber-based robust, design-flexible FD-OCM technique using a Bessel-like LP 02 mode is demonstrated. Extended DOF compared to Gaussian illumination of equal spot-size at focus is reported. We characterize the resolution performance of this system.
Conference Paper
Full-text available
We model the full image formation process in FD-OCM for a Bessel-like LP02 illumination beam as well as Gaussian beams. The LP02 beam generated in a HOM fiber enables design flexibility and an extended DOF. © 2022 The Author(s) Optical Coherence Tomography (OCT) is a 3D imaging technique that is based on interferometric analysis of light that is ba...
Article
Full-text available
Optical coherence tomography (OCT) has revolutionized ophthalmic diagnosis as a non‐invasive, cross‐sectional imaging technique in the last 30 years and hence is one of the fastest adopted advanced imaging technologies in the history of medicine. A miniaturization of OCT devices would not only reduce size but ideally also reduce costs and therefore...
Article
Full-text available
Precise intraoperative brain tumor visualization supports surgeons in achieving maximal safe resection. In this sense, improved prognosis in patients with high-grade gliomas undergoing protoporphyrin IX fluorescence-guided surgery has been demonstrated. Phase fluorescence lifetime imaging in the frequency-domain has shown promise to distinguish wea...
Conference Paper
We introduce a new approach to reduce uncorrelated background signals from fluorescence imaging data, using real-time subtraction of background light. Our method allows removing image artifacts that cause signal clipping in a conventional imaging setup.
Article
Full-text available
In this work, we present a significant step toward in vivo ophthalmic optical coherence tomography and angiography on a photonic integrated chip. The diffraction gratings used in spectral-domain optical coherence tomography can be replaced by photonic integrated circuits comprising an arrayed waveguide grating. Two arrayed waveguide grating designs...
Article
Full-text available
Intrinsic optical signals constitute a noninvasive biomarker promising the objective assessment of retinal photoreceptor function. We employed a commercial optical coherence tomography (OCT) system and an OCT signal model for evaluation of optical path length (OPL) changes in the temporal outer retina of five healthy subjects during light adaptatio...
Article
Full-text available
We present a robust fiber-based setup for Bessel-like beam extended depth-of-focus Fourier-domain optical coherence microscopy, where the Bessel-like beam is generated in a higher order mode fiber module. In this module a stable guided LP02 core mode is selectively excited by a long period grating written in the higher order mode fiber. Imaging per...
Article
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Photonic integrated circuits (PIC) provide promising functionalities to significantly reduce the size and costs of optical coherence tomography (OCT) systems. This paper presents an imaging platform operating at a center wavelength of 830 nm for ophthalmic application using PIC-based swept source OCT. An on-chip Mach–Zehnder interferometer (MZI) co...
Article
OBJECTIVE Fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) is nowadays widely applied for improved resection of glioblastomas (GBMs). Initially, pretreatment with dexamethasone was considered to be essential for optimal fluorescence effect. However, recent studies reported comparably high rates of visible fluorescence in GBMs despite...
Article
Full-text available
Significance: After three decades, more than 75,000 publications, tens of companies being involved in its commercialization, and a global market perspective of about USD 1.5 billion in 2023, optical coherence tomography (OCT) has become one of the fastest successfully translated imaging techniques with substantial clinical and economic impacts and...
Article
Full-text available
This Roadmap article on digital holography provides an overview of a vast array of research activities in the field of digital holography. The paper consists of a series of 25 sections from the prominent experts in digital holography presenting various aspects of the field on sensing, 3D imaging and displays, virtual and augmented reality, microsco...
Article
Full-text available
Objective: Despite advancements of intraoperative visualization, the difficulty to visually distinguish adenoma from adjacent pituitary gland due to textural similarities may lead to incomplete adenoma resection or impairment of pituitary function. The aim of this study was to investigate optical coherence tomography (OCT) imaging in combination wi...
Article
Full-text available
Maximal safe resection is a key strategy for improving patient prognosis in the management of brain tumors. Intraoperative fluorescence guidance has emerged as a standard in the surgery of high-grade gliomas. The administration of 5-aminolevulinic acid prior to surgery induces tumor-specific accumulation of protoporphyrin IX, which emits red fluore...
Article
Full-text available
In this work, a novel fiber optic sensor based on Fabry–Pérot interferometry is adopted in an optical coherence photoacoustic microscopy (OC-PAM) system to enable high-resolution in vivo imaging. The complete OC-PAM system is characterized using the fiber optic sensor for photoacoustic measurement. After characterization, the performance of the sys...
Article
Full-text available
Achieving high resolution in optical coherence tomography typically requires the continuous extension of the spectral bandwidth of the light source. This work demonstrates an alternative approach: combining two, discrete spectral windows located in the visible spectrum with a trained conditional generative adversarial network (cGAN) to reconstruct...
Article
Full-text available
Ocular aberrometry is an essential technique in vision science and ophthalmology. We demonstrate how a phase-sensitive single mode fiber-based swept source optical coherence tomography (SS-OCT) setup can be employed for quantitative ocular aberrometry with digital adaptive optics (DAO). The system records the volumetric point spread function at the...
Article
Full-text available
The pyramid wavefront sensor (P-WFS) has replaced the Shack-Hartmann (SH-) WFS as the sensor of choice for high-performance adaptive optics (AO) systems in astronomy. Many advantages of the P-WFS, such as its adjustable pupil sampling and superior sensitivity, are potentially of great benefit for AO-supported imaging in ophthalmology as well. Howev...
Article
A novel fast proximal scanning method, to the best of our knowledge, termed fiber-core-targeted scanning (FCTS), is proposed for illuminating individual fiber cores sequentially to remove the pixelation effect in fiber bundle (FB) imaging. FCTS is based on a galvanometer scanning system. Through a dynamic control of the scan trajectory and speed us...
Article
Full-text available
Cancer cells often adapt their lipid metabolism to accommodate the increased fatty acid demand for membrane biogenesis and energy production. Upregulation of fatty acid uptake from the environment of cancer cells has also been reported as an alternative mechanism. To investigate the role of lipids in tumor onset and progression and to identify pote...
Article
Digital holographic microscopes provide quantitative phase images of transparent objects like biological cells. These phase images can in turn provide a host of parameters based on the object morphology, which could be used for object identification. But one of the biggest challenges in digital holographic microscopy is the design of compact setups...
Article
Full-text available
Pituitary adenomas count among the most common intracranial tumors. During pituitary oncogenesis structural, textural, metabolic and molecular changes occur which can be revealed with our integrated ultrahigh-resolution multimodal imaging approach including optical coherence tomography (OCT), multiphoton microscopy (MPM) and line scan Raman microsp...
Preprint
The pyramid wavefront sensor (P-WFS) has replaced the Shack-Hartmann (SH-) WFS as sensor of choice for high performance adaptive optics (AO) systems in astronomy because of its flexibility in pupil sampling, its dynamic range, and its improved sensitivity in closed-loop application. Usually, a P-WFS requires modulation and high precision optics tha...
Conference Paper
Purpose:For various applications during ophthalmic surgery spectral-domain optical coherence tomography (SD-OCT) is limited through its low A-scan rate and imaging depth. We present a versatile swept-source OCT (SS-OCT) engine, which addresses a large collection of use cases, ranging from axial eye length measurements to live volumetric visualizati...
Article
Full-text available
The combination of manifold optical imaging modalities resulting in multimodal optical systems allows to discover a larger number of biomarkers than using a single modality. The goal of multimodal imaging systems is to increase the diagnostic performance through the combination of complementary modalities, e.g. optical coherence tomography (OCT) an...
Preprint
Full-text available
The combination of manifold optical imaging modalities resulting in multimodal optical systems allows to discover a larger number of biomarkers than using a single modality. The goal of multimodal imaging systems is to increase the diagnostic performance through the combination of complementary modalities, e.g. optical coherence tomography (OCT) an...
Article
Full-text available
Multiphoton microscopy (MPM) including two-photon excited fluorescence (TPEF), second harmonic generation (SHG), coherent anti-Stokes Raman scattering (CARS) is an important tool in biology and medicine to explore the dynamics of cells and to investigate tissue structure in living systems and biopsies. However, MPM still suffers from limited applic...
Article
Full-text available
A novel non-iterative digital adaptive optics technique is presented in which the wavefront error is calculated using the phase difference between the pupil field and its digital copies translated by a pixel along the horizontal and vertical direction in the pupil plane. This method provides slope data per pixel, thus can generate > 50k local slope...
Article
The guest editors introduce a feature issue containing papers based on research presented at the OSA Biophotonics Congress (the former BIOMED) 20-23 April 2020, in the first all virtual, web conference format undertaken by OSA.
Chapter
DESCRIPTION Optical coherence tomography (OCT) is an imaging technique that uses low-coherence interferometry to construct 3D images with micrometer-scale resolution. It is the imaging modality used in optical coherence elastography (OCE) to measure sample deformation; as such, a detailed analysis of OCT is required to gain a clear understanding of...
Article
Full-text available
Oncological diseases account for a significant portion of the burden on public healthcare systems with associated costs driven primarily by complex and long-lasting therapies. Through the visualization of patient-specific morphology and functional-molecular pathways, cancerous tissue can be detected and characterized non-invasively, so as to provid...
Article
Full-text available
Maximal safe tumor resection remains the key prognostic factor for improved prognosis in brain tumor patients. Despite 5-aminolevulinic acid-based fluorescence guidance the neurosurgeon is, however, not able to visualize most low-grade gliomas (LGG) and infiltration zone of high-grade gliomas (HGG). To overcome the need for a more sensitive visuali...
Article
Full-text available
We introduce a new approach to reduce uncorrelated background signals from fluorescence imaging data, using real-time subtraction of background light. This approach takes advantage of the short fluorescence lifetime of most popular fluorescent activity reporters, and the low duty-cycle of ultrafast lasers. By synchronizing excitation and recording,...
Article
Full-text available
Objective: 3D optical coherence tomography (OCT) is used for analyses of human placenta organoids in situ without sample preparation. Methods: The trophoblast organoids analyzed were derived from primary human trophoblast. In this study a custom made ultra-high-resolution spectral domain OCT system with uniform spatial and axial resolution of 2....
Article
Full-text available
Ultrahigh resolution optical coherence tomography (UHR-OCT) for differentiating pituitary gland versus adenoma tissue has been investigated for the first time, indicating more than 80 % accuracy. For biomarker identification, OCT images of paraffine embedded tissue are correlated to histopathological slices. The identified biomarkers are verified o...