Optical cohrence tomography (OCT)

Application and development of ultrafast MHz OCT systems

OCT is a noninvasive Imaging modality which is typically used for high resolution (~10µm), three dimensional imaging of scattering tissue. By using home built FDML laser technology we achieve imaging speeds of several million depth scans per second, which is one to two orders of magnitude higher than current commercially available systems (MHz-OCT).

These high imaging speeds already proved to be very useful in clinical applications, by reducing acquisition times and therefore reducing motion artifacts. But the high speed also gives access to the phase of the detected light and will thus allow the use of new numerical approaches for image quality enhancement and functional imaging with Swept-Source-OCT.

Our working group is conducting research in the field of OCT to develop new technologies and to identify possible fields of application.

The focus areas are:

  • MHz-OCT - Ultra-fast OCT imaging with several million depth scans per second
  • LARA-OCT - Large area robotically assisted OCT
  • VR-OCT - Real-time computation and rendering of entire OCT volumes in a virtual environment
  • Eye OCT - application of MHz-OCT to the eye for visualization of the retina or the anterior segment of the eye
  • Phase sensitive OCT - enhancement of the information content of an OCT image by adding phase contrast
  • Multispectral OCT - combination of RGB and OCT images for improved visualization of morphological structures

related Publications

2024

Berenice Schulte, Madita Göb, Awanish Pratap Singh, Simon Lotz, Wolfgang Draxinger, Mario Pieper, Maik Rahlves, Robert Huber, and Mark Ellrichmann,
High-resolution rectoscopy using MHz optical coherence tomography: a step towards real time 3D endoscopy, Scientific Reports , vol. 14, no. 1, pp. 4672, 02 2024.
DOI:10.1038/s41598-024-55338-5
Bibtex: BibTeX
@article{RN5474,
   author = {Schulte, Berenice;Göb, Madita;Singh, Awanish Pratap;Lotz, Simon;Draxinger, Wolfgang;Heimke, Marvin;pieper, Mario;Heinze, Tillmann;Wedel, Thilo;Rahlves, Maik;Huber, Robert and Ellrichmann, Mark},
   title = {High-resolution rectoscopy using MHz optical coherence tomography: a step towards real time 3D endoscopy},
   journal = {Scientific Reports},
   volume = {14},
   number = {1},
   pages = {4672},
   ISSN = {2045-2322},
   DOI = {10.1038/s41598-024-55338-5},
   url = {https://doi.org/10.1038/s41598-024-55338-5},
   year = {2024},
   type = {Journal Article}
}
Jessica Kren, Patrick Kuppler, Steffen Buschschlüter, Nicolas Detrez, Sazgar Burhan, Robert Huber, Ralf Brinkmann, and Matteo Mario Bonsanto,
Mechanical characteristics of glioblastoma and peritumoral tumor-free human brain tissue, Acta Neurochirurgica , vol. 166, no. 1, pp. 102, 02 2024.
DOI:10.1007/s00701-024-06009-x
Bibtex: BibTeX
@article{RN5472,
   author = {Kren, Jessica;Skambath, Isabelle;Kuppler, Patrick;Buschschlüter, Steffen;Detrez, Nicolas;Burhan, Sazgar;Huber, Robert;Brinkmann, Ralf and Bonsanto, Matteo Mario},
   title = {Mechanical characteristics of glioblastoma and peritumoral tumor-free human brain tissue},
   journal = {Acta Neurochirurgica},
   volume = {166},
   number = {1},
   pages = {102},
   ISSN = {0942-0940},
   DOI = {10.1007/s00701-024-06009-x},
   url = {https://doi.org/10.1007/s00701-024-06009-x},
   year = {2024},
   type = {Journal Article}
}
Patrick Kuppler, Paul Strenge, Birgit Lange, Sonja Spahr-Hess, Wolfgang Draxinger, Christian Hagel, Dirk Theisen-Kunde, Ralf Brinkmann, Robert Huber, Volker Tronnier, and Matteo Mario Bonsanto,
Microscope-integrated optical coherence tomography for in vivo human brain tumor detection with artificial intelligence, Journal of Neurosurgery , pp. 1 - 9, 2024. American Association of Neurological Surgeons.
DOI:10.3171/2024.1.JNS231511
Bibtex: BibTeX
@article { Microscopeintegratedopticalcoherencetomographyforinvivohumanbraintumordetectionwithartificialintelligence,
      author = "Patrick Kuppler and Paul Strenge and Birgit Lange and Sonja Spahr-Hess and Wolfgang Draxinger and Christian Hagel and Dirk Theisen-Kunde and Ralf Brinkmann and Robert Huber and Volker Tronnier and Matteo Mario Bonsanto",
      title = "Microscope-integrated optical coherence tomography for in vivo human brain tumor detection with artificial intelligence",
      journal = "Journal of Neurosurgery",
      year = "2024",
      publisher = "American Association of Neurological Surgeons",
      doi = "10.3171/2024.1.JNS231511",
      pages=      "1 - 9",
      url = "https://thejns.org/view/journals/j-neurosurg/aop/article-10.3171-2024.1.JNS231511/article-10.3171-2024.1.JNS231511.xml"
}
Sazgar Burhan, Nicolas Detrez, Katharina Rewerts, Paul Strenge, Steffen Buschschlüter, Jessica Kren, Christian Hagel, Matteo Mario Bonsanto, Ralf Brinkmann, and Robert Huber,
Phase unwrapping for MHz optical coherence elastography and application to brain tumor tissue, Biomed. Opt. Express , vol. 15, no. 2, pp. 1038--1058, 2024. Optica Publishing Group.
DOI:10.1364/BOE.510020
Bibtex: BibTeX
@article{Burhan:24,
author = {Sazgar Burhan and Nicolas Detrez and Katharina Rewerts and Paul Strenge and Steffen Buschschl\"{u}ter and Jessica Kren and Christian Hagel and Matteo Mario Bonsanto and Ralf Brinkmann and Robert Huber},
journal = {Biomed. Opt. Express},
keywords = {High speed imaging; Imaging systems; In vivo imaging; Magnetic resonance imaging; Phase noise; Phase shift},
number = {2},
pages = {1038--1058},
publisher = {Optica Publishing Group},
title = {Phase unwrapping for MHz optical coherence elastography and application to brain tumor tissue},
volume = {15},
month = {Feb},
year = {2024},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-15-2-1038},
doi = {10.1364/BOE.510020},
abstract = {During neuro-oncologic surgery, phase-sensitive optical coherence elastography (OCE) can be valuable for distinguishing between healthy and diseased tissue. However, the phase unwrapping process required to retrieve the original phase signal is a challenging and critical task. To address this issue, we demonstrate a one-dimensional unwrapping algorithm that recovers the phase signal from a 3.2\&\#x2005;MHz OCE system. With a processing time of approximately 0.11 s per frame on the GPU, multiple 2\&\#x03C0; wraps are detected and corrected. By utilizing this approach, exact and reproducible information on tissue deformation can be obtained with pixel accuracy over the entire acquisition time. Measurements of brain tumor-mimicking phantoms and human ex vivo brain tumor samples verified the algorithm\&\#x0027;s reliability. The tissue samples were subjected to a 200\&\#x2005;ms short air pulse. A correlation with histological findings confirmed the algorithm\&\#x0027;s dependability.},
}
Awanish Pratap Singh, Madita Göb, Martin Ahrens, Tim Eixmann, Berenice Schulte, Hinnerk Schulz-Hildebrandt, Gereon Hüttmann, Mark Ellrichmann, Robert Huber, and Maik Rahlves,
Virtual Hall sensor triggered multi-MHz endoscopic OCT imaging for stable real-time visualization, Opt. Express , vol. 32, no. 4, pp. 5809--5825, 2024. Optica Publishing Group.
DOI:10.1364/OE.514636
Bibtex: BibTeX
@article{Singh:24,
author = {Awanish Pratap Singh and Madita G\"{o}b and Martin Ahrens and Tim Eixmann and Berenice Schulte and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Mark Ellrichmann and Robert Huber and Maik Rahlves},
journal = {Opt. Express},
keywords = {Biomedical imaging; Endoscopic imaging; Imaging systems; Optical coherence tomography; Real time imaging; Vertical cavity surface emitting lasers},
number = {4},
pages = {5809--5825},
publisher = {Optica Publishing Group},
title = {Virtual Hall sensor triggered multi-MHz endoscopic OCT imaging for stable real-time visualization},
volume = {32},
month = {Feb},
year = {2024},
url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-32-4-5809},
doi = {10.1364/OE.514636},
abstract = {Circumferential scanning in endoscopic imaging is crucial across various disciplines, and optical coherence tomography (OCT) is often the preferred choice due to its high-speed, high-resolution, and micron-scale imaging capabilities. Moreover, real-time and high-speed 3D endoscopy is a pivotal technology for medical screening and precise surgical guidance, among other applications. However, challenges such as image jitter and non-uniform rotational distortion (NURD) are persistent obstacles that hinder real-time visualization during high-speed OCT procedures. To address this issue, we developed an innovative, low-cost endoscope that employs a brushless DC motor for scanning, and a sensorless technique for triggering and synchronizing OCT imaging with the scanning motor. This sensorless approach uses the motor\&\#x2019;s electrical feedback (back electromotive force, BEMF) as a virtual Hall sensor to initiate OCT image acquisition and synchronize it with a Fourier Domain Mode-Locked (FDML)-based Megahertz OCT system. Notably, the implementation of BEMF-triggered OCT has led to a substantial reduction in image jitter and NURD (\<4 mrad), thereby opening up a new window for real-time visualization capabilities. This approach suggests potential benefits across various applications, aiming to provide a more accurate, deployable, and cost-effective solution. Subsequent studies can explore the adaptability of this system to specific clinical scenarios and its performance under practical endoscopic conditions.},
}

2023

Marie Klufts, A. Martínez Jiménez, Simon Lotz, Muhammad Asim Bashir, Tom Pfeiffer, Alexander Mlynek, Wolfgang Wieser, Alexander Chamorovskiy, Adrian Bradu, Adrian Podoleanu, and Robert Huber,
828 kHz retinal imaging with an 840 nm Fourier domain mode locked laser, Biomed. Opt. Express , vol. 14, no. 12, pp. 6493-6508, Nov. 2023. Optica Publishing Group.
DOI:10.1364/BOE.504302
Bibtex: BibTeX
@article{Klufts:23,
author = {Marie Klufts and Alejandro Martinez Jimenez and Simon Lotz and Muhammad Asim Bashir and Tom Pfeiffer and Alexander Mlynek and Wolfgang Wieser and Alexander Chamorovskiy and Adrian Bradu and Adrian Podoleanu and Robert Huber},
journal = {Biomed. Opt. Express},
keywords = {Analog to digital converters; Laser beams; Laser imaging; Laser modes; Point spread function; Vertical cavity surface emitting lasers},
number = {12},
pages = {6493--6508},
publisher = {Optica Publishing Group},
title = {828 kHz retinal imaging with an 840\&\#x2005;nm Fourier domain mode locked laser},
volume = {14},
month = {Dec},
year = {2023},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-14-12-6493},
abstract = {This paper presents a Fourier domain mode locked (FDML) laser centered around 840 nm. It features a bidirectional sweep repetition rate of 828 kHz and a spectral bandwidth of 40 nm. An axial resolution of ∼9.9 µm in water and a 1.4 cm sensitivity roll-off are achieved. Utilizing a complex master-slave (CMS) recalibration method and due to a sufficiently high sensitivity of 84.6 dB, retinal layers of the human eye in-vivo can be resolved during optical coherence tomography (OCT) examination. The developed FDML laser enables acquisition rates of 3D-volumes with a size of 200 × 100 × 256 voxels in under 100 milliseconds. Detailed information on the FDML implementation, its challenging design tasks, and OCT images obtained with the laser are presented in this paper.},
}
Wolfgang Draxinger, Dirk Theisen-Kunde, Lion Schuetz, Nicolas Detrez, Paul Strenge, Maximilian Rixius, Veit Danicke, Wolfgang Wieser, Jessica Kren, Patrick Kuppler, Sonja Spar-Hess, Matteo M. Bonsanto, Ralf Brinkmann, and Robert Huber,
Microscope integrated realtime high density 4D MHz-OCT in neurosurgery: a depth and tissue resolving visual contrast channel and the challenge of fused presentation, in Translational Biophotonics: Diagnostics and Therapeutics III , Zhiwei Huang and Lothar D. Lilge, Eds. SPIE, 082023. pp. 126270W.
DOI:10.1117/12.2670953
Bibtex: BibTeX
@inproceedings{10.1117/12.2670953,
author = {Wolfgang Draxinger and Dirk Theisen-Kunde and Lion Schuetz and Nicolas Detrez and Paul Strenge and Maximilian Rixius and Veit Danicke and Wolfgang Wieser and Jessica Kren and Patrick Kuppler and Sonja Spar-Hess and Matteo Mario Bonsanto M.D. and Ralf Brinkmann and Robert Huber},
title = {{Microscope integrated realtime high density 4D MHz-OCT in neurosurgery: a depth and tissue resolving visual contrast channel and the challenge of fused presentation}},
volume = {12627},
booktitle = {Translational Biophotonics: Diagnostics and Therapeutics III},
editor = {Zhiwei Huang and Lothar D. Lilge},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {126270W},
abstract = {Microscope integrated realtime 4D MHz-OCT operating at high scanning densities are capable of capturing additional visual contrast resolving depth and tissue. Even within a plain C-scan en-face projection structures are recognizable, that are not visible in a white light camera image. With advanced post processing methods, such as absorbtion coefficient mapping, and morphological classifiers more information is extraced. Presentation to the user in an intuitive way poses practical challenges that go beyond the implementation of a mere overlay display. We present our microscope integrated high speed 4D OCT imaging system, its clinical study use for in-vivo brain tissue imaging, and user feedback on the presentation methods we developed.},
keywords = {optical coherence tomography, neurosurgery, tissue contrast, image fusion, surgical guidance, theranostics},
year = {2023},
doi = {10.1117/12.2670953},
URL = {https://doi.org/10.1117/12.2670953}
}
Sazgar Burhan, Nicolas Detrez, Madita Göb, Matteo Mario Bonsanto, Ralf Brinkmann, and Robert Huber,
Advanced FFT-based contrast approach for MHz optical coherence elastography, in Optical Coherence Imaging Techniques and Imaging in Scattering Media V , Benjamin J. Vakoc and Maciej Wojtkowski and Yoshiaki Yasuno, Eds. SPIE, 082023. pp. 1263215.
DOI:10.1117/12.2670957
Bibtex: BibTeX
@inproceedings{10.1117/12.2670957,
author = {Sazgar Burhan and Nicolas Detrez and Madita G{\"o}b and Matteo Mario Bonsanto and Ralf Brinkmann and Robert Huber},
title = {{Advanced FFT-based contrast approach for MHz optical coherence elastography}},
volume = {12632},
booktitle = {Optical Coherence Imaging Techniques and Imaging in Scattering Media V},
editor = {Benjamin J. Vakoc and Maciej Wojtkowski and Yoshiaki Yasuno},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1263215},
abstract = {Optical coherence elastography represents mechanical characteristics of biological tissue in so-called mechanical contrast maps. In addition to the standard intensity image, the contrast map illustrates numerous mechanical tissue features that would otherwise be undetectable. This is of great interest as abnormal physiological changes influence the mechanical behavior of the tissue. We demonstrate an advanced mechanical contrast approach based on the phase signal of our 3.2 MHz optical coherence tomography system. The robustness and performance of this contrast approach is evaluated and discussed based on preliminary results. },
keywords = {Optical Coherence Tomography, OCT, Megahertz OCT, Fourier Domain Mode Locking, Optical Coherence Elastography, OCE, Phase-sensitive OCT, Biomechanics},
year = {2023},
doi = {10.1117/12.2670957},
URL = {https://doi.org/10.1117/12.2670957}
}
Madita Göb, Simon Lotz, Linh Ha-Wissel, Sazgar Burhan, Sven Böttger, Floris Ernst, Jennifer Hundt, and Robert Huber,
Advances in large area robotically assisted OCT (LARA-OCT): towards drive-by continuous motion imaging, in Optical Coherence Imaging Techniques and Imaging in Scattering Media V , Benjamin J. Vakoc and Maciej Wojtkowski and Yoshiaki Yasuno, Eds. SPIE, 082023. pp. 126321N.
DOI:10.1117/12.2670950
Bibtex: BibTeX
@inproceedings{10.1117/12.2670950,
author = {Madita G{\"o}b and Simon Lotz and Linh Ha-Wissel and Sazgar Burhan and Sven B{\"o}ttger and Floris Ernst and Jennifer Hundt and Robert Huber},
title = {{Advances in large area robotically assisted OCT (LARA-OCT): towards drive-by continuous motion imaging}},
volume = {12632},
booktitle = {Optical Coherence Imaging Techniques and Imaging in Scattering Media V},
editor = {Benjamin J. Vakoc and Maciej Wojtkowski and Yoshiaki Yasuno},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {126321N},
abstract = {Optical coherence tomography is a powerful imaging technique to visualize and localize depth-dependent tissue structure to differentiate between healthy and pathological conditions. However, conventional OCT systems are only capable of detecting small areas. To overcome this limitation, we have developed a large area robotically assisted OCT (LARA-OCT) system for automatic acquisition of large OCT images. Using mosaic pattern acquisition and subsequent stitching, we previously demonstrated initial in vivo OCT skin images beyond 10 cm². To improve acquisition speed and reduce dead times, we here demonstrate and analyze LARA-OCT with a new drive-by continuous motion imaging protocol.},
keywords = {Optical Coherence Tomography, Fourier Domain Mode Locking, Robotically Assisted Imaging Systems, Three-dimensional image acquisition, Large Area Scanning, Skin Imaging, OCT, FDML},
year = {2023},
doi = {10.1117/12.2670950},
URL = {https://doi.org/10.1117/12.2670950}
}
Marie Klufts, Simon Lotz, Muhammad Asim Bashir, Tom Pfeiffer, Alexander Mlynek, Wolfgang Wieser, Alexander Chamorovskiy, Vladimir Shidlovski, Adrian Podoleanu, and Robert Huber,
Dual Amplification 850 nm FDML Laser, in 2023 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) , 072023. pp. 1.
DOI:10.1109/CLEO/Europe-EQEC57999.2023.10232019
Bibtex: BibTeX
@INPROCEEDINGS{10232019,
  author={Klufts, M. and Lotz, S. and Bashir, M. A. and Pfeiffer, T. and Mlynek, A. and Wieser, W. and Chamorovskiy, A. and Shidlovski, V. and Podoleanu, A. and Huber, R.},
  booktitle={2023 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)}, 
  title={Dual Amplification 850 nm FDML Laser}, 
  year={2023},
  volume={},
  number={},
  pages={1-1},
  doi={10.1109/CLEO/Europe-EQEC57999.2023.10232019}}
Wolfgang Draxinger, Dirk Theisen-Kunde, Lion Schützeck, Nicolas Detrez, Paul Strenge, Veit Danicke, Jessica Kren, Patrick Kuppler, Sonja Spahr-Hess, Matteo Mario Bonsanto, Ralf Brinkmann, and Robert Huber,
High speed 4D in-vivo OCT imaging of the human brain: creating high density datasets for machine learning toward identification of malign tissue in real time, in High-Speed Biomedical Imaging and Spectroscopy VIII , Kevin K. Tsia and Keisuke Goda, Eds. SPIE, 032023. pp. 123900D.
DOI:10.1117/12.2648505
Bibtex: BibTeX
@inproceedings{10.1117/12.2648505,
author = {Wolfgang Draxinger and Dirk Theisen-Kunde and Lion Sch{\"u}tzeck and Nicolas Detrez and Paul Strenge and Veit Danicke and Jessica Kren and Patrick Kuppler and Sonja Spahr-Hess and Matteo Mario Bonsanto and Ralf Brinkmann and Robert Huber},
title = {{High speed 4D in-vivo OCT imaging of the human brain: creating high density datasets for machine learning toward identification of malign tissue in real time}},
volume = {12390},
booktitle = {High-Speed Biomedical Imaging and Spectroscopy VIII},
editor = {Kevin K. Tsia and Keisuke Goda},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {123900D},
abstract = {Neuro-surgery is challenged by the difficulties of determining brain tumor boundaries during excisions. Optical coherence tomography is investigated as an imaging modality for providing a viable contrast channel. Our MHz-OCT technology enables rapid volumetric imaging, suitable for surgical workflows. We present a surgical microscope integrated MHz-OCT imaging system, which is used for the collection of in-vivo images of human brains, with the purpose of being used in machine learning systems that shall be trained to identify and classify tumorous tissue.},
keywords = {optical coherence tomography, brain tumor, neurosurgery, machine learning, contrast augmentation, histology dataset, clinical study, in-vivo imaging},
year = {2023},
doi = {10.1117/12.2648505},
URL = {https://doi.org/10.1117/12.2648505}
}
Awanish P. Singh, Madita Göb, Martin Ahrens, Tim Eixmann, Hinnerk Schulz-Hildebrandt, Gereon Hüttmann, Robert Huber, and Maik Rahlves,
Synchronous high-speed OCT imaging with sensor less brushless DC motor and FDML laser in a phase-locked loop, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXVII , Joseph A. Izatt and James G. Fujimoto, Eds. SPIE, 032023. pp. 1236703.
DOI:10.1117/12.2652955
Bibtex: BibTeX
@inproceedings{10.1117/12.2652955,
author = {Awanish Pratap Singh and Madita G{\"o}b and Martin Ahrens and Tim Eixmann and Hinnerk Schulz-Hildebrandt and Gereon H{\"u}ttmann and Robert Huber and Maik Rahlves},
title = {{Synchronous high-speed OCT imaging with sensor less brushless DC motor and FDML laser in a phase-locked loop}},
volume = {12367},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXVII},
editor = {Joseph A. Izatt and James G. Fujimoto},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1236703},
abstract = {High-speed endoscopic optical coherence tomography (OCT) imaging in the MHz range has shown great potential in various medical applications ranging from cancer screening to vascular disease monitoring. High-speed imaging always suffers from non-uniform rotational distortion (NURD) due to asynchronous motor rotation with the OCT system. Several research groups have previously attempted to solve this problem, using either an expensive motor with a sensor or numerical correction after data acquisition. However, both techniques pose challenges for practical use. Therefore, in this study, we use an inexpensive sensorless brushless DC motor with a Fourier domain mode-locked (FDML) laser-based MHz OCT system and try to resolve the problem of synchronization using three different modalities, (i) Slave-mode: The FDML frequency serves as a master frequency for the motor, which is phase-locked to the FDML frequency, (ii) Master-mode: The revolution trigger obtained from the motor’s back electromotive force (BEMF) signal serves as a trigger signal for the OCT imaging system, (iii) Both: Fully synchronized setup, where the motor rotation is synchronized with the laser and the imaging system is synchronized with the motor to achieve phase-stable OCT imaging. The first case slightly fluctuates in live preview and imaging due to the absence of a revolution trigger, while the second has varying motor speeds. Therefore, we use the third case to phase-lock the motor with FDML and get a distortion-free live preview and image acquisition. Finally, we demonstrate high-speed SS-OCT structural imaging (at 3.3 MHz A-scan rates) of a finger with a 16 mm diameter probe (at 40,000 rpm).},
keywords = {Optical Coherence Tomography, Endoscopy, FDML , Closed Loop Motor Control, NURD compensation, Brushless DC Motor, Back Electromotive Force},
year = {2023},
doi = {10.1117/12.2652955},
URL = {https://doi.org/10.1117/12.2652955}
}
Sazgar Burhan, Nicolas Detrez, Katharina Rewerts, Madita Göb, Christian Hagel, Matteo M. Bonsanto, Dirk Theisen-Kunde, Robert Huber, and Ralf Brinkmann,
Characterization of brain tumor tissue by time-resolved, phase-sensitive optical coherence elastography at 3.2 MHz line rate, in Advanced Biomedical and Clinical Diagnostic and Surgical Guidance Systems XXI , Caroline Boudoux and James W. Tunnell, Eds. SPIE, 032023. pp. 123680F.
DOI:10.1117/12.2648301
Bibtex: BibTeX
@inproceedings{10.1117/12.2648301,
author = {Sazgar Burhan and Nicolas Detrez and Katharina Rewerts and Madita G{\"o}b and Christian Hagel and Matteo Mario Bonsanto and Dirk Theisen-Kunde and Robert Huber and Ralf Brinkmann},
title = {{Characterization of brain tumor tissue by time-resolved, phase-sensitive optical coherence elastography at 3.2 MHz line rate}},
volume = {12368},
booktitle = {Advanced Biomedical and Clinical Diagnostic and Surgical Guidance Systems XXI},
editor = {Caroline Boudoux and James W. Tunnell},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {123680F},
abstract = {Optical coherence elastography (OCE) offers the possibility of obtaining the mechanical behavior of a tissue. When also  using a non-contact mechanical excitation, it mimics palpation without interobserver variability. One of the most frequently  used techniques is phase-sensitive OCE. Depending on the system, depth-resolved changes in the sub-µm to nm range can  be detected and visualized volumetrically. Such an approach is used in this work to investigate and detect transitions  between healthy and tumorous brain tissue as well as inhomogeneities in the tumor itself to assist the operating surgeon  during tumor resection in the future. We present time-resolved, phase-sensitive OCE measurements on various ex vivo brain tumor samples using an ultra-fast 3.2 MHz swept-source optical coherence tomography (SS-OCT) system with a frame rate of 2.45 kHz. 4 mm line scans are acquired which, in combination with the high imaging speed, allow monitoring and investigation of the sample's behavior in response to the mechanical load. Therefore, an air-jet system applies a 200 ms  short air pulse to the sample, whose non-contact property facilitates the possibility for future in vivo measurements. Since we can temporally resolve the response of the sample over the entire acquisition time, the mechanical properties are evaluated at different time points with depth resolution. This is done by unwrapping the phase data and performing subsequent assessment. Systematic ex vivo brain tumor measurements were conducted and visualized as distribution maps.  The study outcomes are supported by histological analyses and examined in detail.},
keywords = { Optical Coherence Tomography, Optical Coherence Elastography, Phase-sensitive OCT, Fourier Domain Mode Locking, Brain Tumor, Phase Unwrapping, Tissue Characterization, Biomechanics},
year = {2023},
doi = {10.1117/12.2648301},
URL = {https://doi.org/10.1117/12.2648301}
}
Madita Göb, Simon Lotz, Linh Ha-Wissel, Sazgar Burhan, Sven Böttger, Floris Ernst, Jennifer Hundt, and Robert Huber,
Large area robotically assisted optical coherence tomography (LARA-OCT) for skin imaging with MHz-OCT surface tracking, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXVII , Joseph A. Izatt and James G. Fujimoto, Eds. SPIE, 032023. pp. 123670C.
DOI:10.1117/12.2652616
Bibtex: BibTeX
@inproceedings{10.1117/12.2652616,
author = {Madita G{\"o}b and Simon Lotz and Linh Ha-Wissel and Sazgar Burhan and Sven B{\"o}ttger and Floris Ernst and Jennifer Hundt and Robert Huber},
title = {{Large area robotically assisted optical coherence tomography (LARA-OCT) for skin imaging with MHz-OCT surface tracking}},
volume = {12367},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXVII},
editor = {Joseph A. Izatt and James G. Fujimoto},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {123670C},
abstract = {Optical coherence tomography (OCT) is a powerful imaging technique to non-invasively differentiate between healthy skin and pathological conditions. Unfortunately, commercially available OCT-systems are typically slow and not capable of scanning large areas at reasonable speed. Since skin lesions may extend over several square centimeters, potential inflammatory infiltrates remain undetected. Here, we present large area robotically assisted OCT (LARA-OCT) for skin imaging. Therefor a collaborative robot is combined with an existing, home-built 3.3 MHz-OCT-system and for surface tracking an online probe-to-surface control is implemented which is solely based on the OCT surface signal. It features a combined surface-distance and surface-orientation closed-loop control algorithm, which enables automatic positioning and alignment of the probe across the target while imaging. This allows to acquire coherent OCT images of skin areas beyond 10 cm<sup>2</sup>. },
keywords = {Optical Coherence Tomography, Fourier Domain Mode Locking, Robotically Assisted Imaging Systems, Three-dimensional image acquisition, Large Area Scanning, Skin Imaging , OCT, FDML},
year = {2023},
doi = {10.1117/12.2652616},
URL = {https://doi.org/10.1117/12.2652616}
}
Paul Strenge, Birgit Lange, Wolfgang Draxinger, Christian Hagel, Christin Grill, Veit Danicke, Dirk Theisen-Kunde, Sonja Spahr-Hess, Matteo M. Bonsanto, Robert Huber, Heinz Handels, and Ralf Brinkmann,
Dual wavelength analysis and classification of brain tumor tissue with optical coherence tomography, in Advanced Biomedical and Clinical Diagnostic and Surgical Guidance Systems XXI , Caroline Boudoux and James W. Tunnell, Eds. SPIE, 032023. pp. 1236805.
DOI:10.1117/12.2649963
Bibtex: BibTeX
@inproceedings{10.1117/12.2649963,
author = {Paul Strenge and Birgit Lange and Wolfgang Draxinger and Christian Hagel and Christin Grill and Veit Danicke and Dirk Theisen-Kunde and Sonja Spahr-Hess and Matteo M. Bonsanto and Robert Huber and Heinz Handels and Ralf Brinkmann},
title = {{Dual wavelength analysis and classification of brain tumor tissue with optical coherence tomography}},
volume = {12368},
booktitle = {Advanced Biomedical and Clinical Diagnostic and Surgical Guidance Systems XXI},
editor = {Caroline Boudoux and James W. Tunnell},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1236805},
abstract = {The ill-defined tumor borders of glioblastoma multiforme pose a major challenge for the surgeon during tumor resection,  since the goal of the tumor resection is the complete removal, while saving as much healthy brain tissue as possible. In  recent years, optical coherence tomography (OCT) was successfully used to classify white matter from tumor infiltrated  white matter by several research groups. Motivated by these results, a dataset was created, which consisted of sets of  corresponding ex vivo OCT images, which were acquired by two OCT-systems with different properties (e.g. wavelength  and resolution). Each image was annotated with semantic labels. The labels differentiate between white and gray matter  and three different stages of tumor infiltration. The data from both systems not only allowed a comparison of the ability of  a system to identify the different tissue types present during the tumor resection, but also enable a multimodal tissue  analysis evaluating corresponding OCT images of the two systems simultaneously. A convolutional neural network with  dirichlet prior was trained, which allowed to capture the uncertainty of a prediction. The approach increased the sensitivity  of identifying tumor infiltration from 58 % to 78 % for data with a low prediction uncertainty compared to a previous  monomodal approach. },
keywords = {optical coherence tomography, oct, brain, classification, tumor, dual wavelength, glioblastoma multiforme, tissue analysis},
year = {2023},
doi = {10.1117/12.2649963},
URL = {https://doi.org/10.1117/12.2649963}
}
Sazgar Burhan, Nicolas Detrez, Katharina Rewerts, Madita Göb, Steffen Buschschlüter, Christian Hagel, Matteo M. Bonsanto, Dirk Theisen-Kunde, Robert Huber, and Ralf Brinkmann,
Phase analysis strategies for MHz OCE in the large displacement regime, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXVII , Joseph A. Izatt and James G. Fujimoto, Eds. SPIE, 2023. pp. 123670Q.
DOI:10.1117/12.2652847
Bibtex: BibTeX
@inproceedings{10.1117/12.2652847,
author = {Sazgar Burhan and Nicolas Detrez and Katharina Rewerts and Madita G{\"o}b and Steffen Buschschl{\"u}ter and Christian Hagel and Matteo Mario Bonsanto M.D. and Dirk Theisen-Kunde and Robert Huber and Ralf Brinkmann},
title = {{Phase analysis strategies for MHz OCE in the large displacement regime}},
volume = {12367},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXVII},
editor = {Joseph A. Izatt and James G. Fujimoto},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {123670Q},
abstract = {In neurosurgical tumor operations on the central nervous system, intraoperative haptic information often assists for discrimination between healthy and diseased tissue. Thus, it can provide the neurosurgeon with additional intraoperative source of information during resection, next to the visual information by the light microscope, fluorescent dyes and neuronavigation. One approach to obtain elastic and viscoelastic tissue characteristics non-subjectively is phase-sensitive optical coherence elastography (OCE), which is based on the principle of optical coherence tomography (OCT). While phase-sensitive OCE offers significantly higher displacement sensitivity inside a sample than commonly used intensity-based correlation methods, it requires a reliable algorithm to recover the phase signal, which is mathematically restricted in the -&pi; to &pi; range. This problem of phase wrapping is especially critical for inter-frame phase analysis since the time intervals between two referenced voxels is long. Here, we demonstrate a one-dimensional unwrapping algorithm capable of removing up to 4&pi;-ambiguities between two frames in the complex phase data obtained from a 3.2 MHz-OCT system. The high sampling rate allows us to resolve large sample displacements induced by a 200 ms air pulse and acquires pixel-precise detail information. The deformation behavior of the tissue can be monitored over the entire acquisition time, offering various subsequent mechanical analysis procedures. The reliability of the algorithm and imaging concept was initially evaluated using different brain tumor mimicking phantoms. Additionally, results from human ex vivo brain tumor samples are presented and correlated with histological findings supporting the robustness of the algorithm.},
keywords = {Optical Coherence Tomography, Megahertz OCT, Fourier Domain Mode Locking, Optical Coherence Elastography, Phase-sensitive OCT, Phase Unwrapping, Brain tumor, Biomechanics},
year = {2023},
doi = {10.1117/12.2652847},
URL = {https://doi.org/10.1117/12.2652847}
}

2022

Linh Ha-Wissel, Handan Yasak, Robert Huber, Detlef Zillikens, Ralf J. Ludwig, Diamant Thaci, and Jennifer E. Hundt,
Case report: Optical coherence tomography for monitoring biologic therapy in psoriasis and atopic dermatitis, Frontiers in Medicine , vol. 9, 09 2022.
DOI:10.3389/fmed.2022.995883
File: fmed.2022.995883
Bibtex: BibTeX
@article{RN5359,
   author = {Ha-Wissel, L.;Yasak, H.;Huber, R.;Zillikens, D.;Ludwig, R. J.;Thaçi, D. and Hundt, J. E.},
   title = {Case report: Optical coherence tomography for monitoring biologic therapy in psoriasis and atopic dermatitis},
   journal = {Front Med (Lausanne)},
   volume = {9},
   pages = {995883},
   ISSN = {2296-858X (Print)
2296-858x},
   DOI = {10.3389/fmed.2022.995883},
   year = {2022},
   type = {Journal Article}
}
Paul Strenge, Birgit Lange, Wolfgang Draxinger, Christin Grill, Veit Danicke, Dirk Theisen-Kunde, Christian Hagel, Sonja Spahr-Hess, Matteo M. Bonsanto, Heinz Handels, Ralf Brinkmann, and Robert Huber,
Differentiation of different stages of brain tumor infiltration using optical coherence tomography: Comparison of two systems and histology, Frontiers in Oncology , 08 2022.
DOI:10.3389/fonc.2022.896060
Bibtex: BibTeX
@article{Strenge-2022,
   author = {Strenge, P.;Lange, B.;Grill,C.;Danicke,V.;Theisen-Kunde, D.;Hagel, C.;Spahr-Hess, S.;;Bonsanto, Matteo M.;Handels, H.; and Huber, R.;Brinkmann, R.},
   title = {Differentiation of different stages of brain tumor infiltration using optical coherence tomography: Comparison of two systems and histology},
   journal = {Frontiers in Oncology},
Keywords = {AG-Huber_FDML, AG-Huber_OCT, brain, tumor, glioblastoma multiforme, OCT, neural network, attenuation (absorption)
coefficient, optical coherence tomography},
   DOI = {https://doi.org/10.3389/fonc.2022.896060},
   url = {https://www.frontiersin.org/articles/10.3389/fonc.2022.896060/full},
   year = {2022},
   type = {Journal Article}
}
Paul Strenge, Birgit Lange, Christin Grill, Wolfgang Draxinger, Veit Danicke, Dirk Theisen-Kunde, Christian Hagel, Sonja Spahr-Hess, Matteo M. Bonsanto, Robert Huber, Heinz Handels, and Ralf Brinkmann,
Registration of histological brain images onto optical coherence tomography images based on shape information, Physics in Medicine & Biology , 06 2022.
DOI:10.1088/1361-6560/ac6d9d
Bibtex: BibTeX
@article{Strenge2022,
   author = {Strenge, P;Lange, B;Grill, C;Draxinger, W;Danicke, V;Theisen-Kunde, D;Hagel, C;Spahr-Hess, S;Bonsanto, Matteo M.;Huber, R;Handels, H and Brinkmann, R},
   title = {Registration of histological brain images onto optical coherence tomography images based on shape information},
keywords = {brain, glioblastoma multiforme, shape, OCT, optical coherence tomography, AG-Huber_OCT,},
   journal = {Physics in Medicine & Biology},
   ISSN = {0031-9155},
   url = {http://iopscience.iop.org/article/10.1088/1361-6560/ac6d9d},
   year = {2022},
   type = {Journal Article}
}
Madita Göb, Sazgar Burhan, Simon Lotz, and Robert Huber,
Towards ultra-large area vascular contrast skin imaging using multi-MHz-OCT, in Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXVI , Joseph A. Izatt and James G. Fujimoto, Eds. SPIE, 032022. pp. 27 -- 31.
DOI:10.1117/12.2612171
Bibtex: BibTeX
@inproceedings{10.1117/12.2612171,
author = {Madita G{\"o}b and Sazgar Burhan and Simon Lotz and Robert Huber},
title = {{Towards ultra-large area vascular contrast skin imaging using multi-MHz-OCT}},
volume = {11948},
booktitle = {Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXVI},
editor = {Joseph A. Izatt and James G. Fujimoto},
organization = {International Society for Optics and Photonics},
publisher = {SPIE},
pages = {1194807},
abstract = {We demonstrate ultra-large field of view OCT scanning using standard optics, a X-Y-galvanometer scanner and a synchronously driven motorized XYZ-positioning stage. The integration of a movable stage into our self-built 3.3 MHz- OCT system allows acquiring coherent ultra-large area images, fully leveraging the high speed potential of our system. For fast OCT-angiography, one galvanometer axis scanner is driven in a repetitive sawtooth pattern, fully synchronized to the movement of the linear stage, to obtain multiple measurements at each position. This technique requires exact synchronization, precise repositioning, and uniform movements with low tolerances to ensure a minimum revisitation error. We analyze error and performance of our setup and demonstrate angiographic imaging.},
keywords = {Optical Coherence Tomography, Fourier Domain Mode Locking, FDML, Optical Coherence Angiography, OCTA, Medical optics and biotechnology, Medical imaging, Three-dimensional image acquisition, Scanners, Microscopy},
year = {2022},
doi = {10.1117/12.2612171},
URL = {https://doi.org/10.1117/12.2612171}
}
Madita Göb, Tom Pfeiffer, Wolfgang Draxinger, Simon Lotz, Jan Philip Kolb, and Robert Huber,
Continuous spectral zooming for in vivo live 4D-OCT with MHz A-scan rates and long coherence, Biomed. Opt. Express , vol. 13, no. 2, pp. 713--727, 02 2022. OSA.
DOI:10.1364/BOE.448353
Bibtex: BibTeX
@article{Gob:22,
author = {Madita G\"{o}b and Tom Pfeiffer and Wolfgang Draxinger and Simon Lotz and Jan Philip Kolb and Robert Huber},
journal = {Biomed. Opt. Express},
keywords = {High speed imaging; Image processing; Image quality; In vivo imaging; Range imaging; Vertical cavity surface emitting lasers},
number = {2},
pages = {713--727},
publisher = {Optica Publishing Group},
title = {Continuous spectral zooming for in vivo live 4D-OCT with MHz A-scan rates and long coherence},
volume = {13},
month = {Feb},
year = {2022},
url = {https://opg.optica.org/boe/abstract.cfm?URI=boe-13-2-713},
doi = {10.1364/BOE.448353},
abstract = {We present continuous three-dimensional spectral zooming in live 4D-OCT using a home-built FDML based OCT system with 3.28 MHz A-scan rate. Improved coherence characteristics of the FDML laser allow for imaging ranges up to 10 cm. For the axial spectral zoom feature, we switch between high resolution and long imaging range by adjusting the sweep range of our laser. We present a new imaging setup allowing for synchronized adjustments of the imaging range and lateral field of view during live OCT imaging. For this, a novel inline recalibration algorithm was implemented that enables numerical k-linearization of the raw OCT fringes for every frame instead of every volume. This is realized by acquiring recalibration data within the dead time of the raster scan at the turning points of the fast axis scanner. We demonstrate in vivo OCT images of fingers and hands at different resolution modes and show real three-dimensional zooming during live 4D-OCT. A three-dimensional spectral zooming feature for live 4D-OCT is expected to be a useful tool for a wide range of biomedical, scientific and research applications, especially in OCT guided surgery.},
}
Konstantin Yashin, Matteo Mario Bonsanto, Ksenia Achkasova, Anna Zolotova, Al-Madhaji Wael, Elena Kiseleva, Alexander Moiseev, Igor Medyanik, Leonid Kravets, Robert Huber, Ralf Brinkmann, and Natalia Gladkova,
OCT-Guided Surgery for Gliomas: Current Concept and Future Perspectives, Diagnostics , vol. 12, no. 2, pp. 335, 01 2022.
DOI:10.3390/diagnostics12020335
File: 335
Bibtex: BibTeX
@article{Yashin-2022,
   author = {Yashin, K;Bonsanto, M M;Achkasova, K;Zolotova, A;Wael, Al-M;Kiseleva, E;Moiseev, A;Medyanik, I;Kravets, L;Huber, R;Brinkmann, R and Gladkova, N},
   title = {OCT-Guided Surgery for Gliomas: Current Concept and Future Perspectives},
   journal = {Diagnostics},
   volume = {12},
   number = {2},
   pages = {335},
   ISSN = {2075-4418},
keywords = {AG-Huber; optical coherence tomography; brain imaging; neurosurgical guidance; brain tumor; minimally invasive theranostics; intraoperative imaging},
   url = {https://www.mdpi.com/2075-4418/12/2/335},
   year = {2022},
   type = {Journal Article}
}

2021

Madita Göb, Sazgar Burhan, Wolfgang Draxinger, Jan Philip Kolb, and Robert Huber,
Towards densely sampled ultra-large area multi-MHz-OCT for in vivo skin measurements beyond 1 cm2/sec, in European Conferences on Biomedical Optics 2021 (ECBO) , Optical Society of America, Dec.2021. pp. EW3C.4.
DOI:10.1117/12.2616054
Bibtex: BibTeX
@inproceedings{Gob:21,
author = {Madita G\"{o}b and Sazgar Burhan and Wolfgang Draxinger and Jan Philip Kolb and Robert Huber},
booktitle = {European Conferences on Biomedical Optics 2021 (ECBO)},
journal = {European Conferences on Biomedical Optics 2021 (ECBO)},
keywords = {AG-Huber_OCT;Fourier domain mode locking; Image processing; Image quality; Optical coherence tomography; Temporal resolution; Three dimensional imaging},
pages = {EW3C.4},
publisher = {Optical Society of America},
title = {Towards densely sampled ultra-large area multi-MHz-OCT for in vivo skin measurements beyond 1 cm$^2$/sec},
year = {2021},
url = {http://www.osapublishing.org/abstract.cfm?URI=ECBO-2021-EW3C.4},
abstract = {We demonstrate a 3.3 MHz A-scan rate OCT for rapid scanning of large areas of human skin. The mosaicking performance and different OCT imaging modalities including intervolume speckle contrast are evaluated.},
}
Paul Strenge, Birgit Lange, Christin Grill, Wolfgang Draxinger, Veit Danicke, Dirk Theisen-Kunde, Heinz Handels, Matteo M. Bonsanto, Christian Hagel, Robert Huber, and Ralf Brinkmann,
Comparison of two optical coherence tomography systems to identify human brain tumor, Optical Society of America, Dec.2021. pp. EW1C.7.
DOI:10.1117/12.2616044
Bibtex: BibTeX
@inproceedings{Strenge:21,
author = {P. Strenge, B. Lange, C. Grill, W. Draxinger, V. Danicke, D. Theisen-Kunde, H. Handels, M. M. Bonsanto, C. Hagel, R. Huber and R. Brinkmann},
journal = {European Conferences on Biomedical Optics 2021 (ECBO)},
keywords = {AG-Huber_OCT; Absorption coefficient; Attenuation coefficient; Fourier domain mode locking; Multiple scattering; Optical coherence tomography; Spectral domain optical coherence tomography},
pages = {EW1C.7},
publisher = {Optical Society of America},
title = {Comparison of two optical coherence tomography systems to identify human brain tumor},
year = {2021},
url = {https://doi.org/10.1117/12.2616044},
abstract = {The identification of ex vivo brain tumor tissue was investigated with two different optical coherence tomography systems exploiting two optical parameters. The optical parameters were calculated from semantically labelled OCT B-scans.},
}
Nicolas Detrez, Katharina Rewerts, Moritz Matthiae, Steffen Buschschlüter, Matteo M. Bonsanto, Dirk Theisen-Kunde, and Ralf Brinkmann,
Flow Controlled Air Puff Generator Towards In Situ Brain Tumor Detection Based on MHz Optical Coherence Elastography, in ECBO , Optical Society of America, Dec.2021. pp. EW4A.10.
Weblink: https://opg.optica.org/abstract.cfm?uri=ECBO-2021-EW4A.10
Bibtex: BibTeX
@inproceedings{Detrez:21,
author = {N. Detrez, K. Rewerts, M. Matthiae, S. Buschschlueter, M.M. Bonsanto, D. Theisen-Kunde and R. Brinkmann},
journal = {European Conferences on Biomedical Optics 2021 (ECBO)},
keywords = {AG-Huber_OCT},
pages = {EW4A.10},
publisher = {Optical Society of America},
title = {Flow Controlled Air Puff Generator Towards In Situ Brain Tumor Detection Based on MHz Optical Coherence Elastography},
year = {2021},
url = {https://doi.org/10.1117/12.2615022},
abstract = {A precision air puff excitation system for MHz Optical Coherence Elastography in neurosurgery was developed. It enables non-contact soft-tissue excitation down to {\textmu}N, with direct, noncontact force determination via gas flow measurement.},
}