Hinnerk Schulz-Hildebrandt

@article{Kohlfaerber:22,

title = {Dynamic microscopic optical coherence tomography to visualize the morphological and functional micro-anatomy of the airways},

author = {Tabea Kohlfaerber and Mario Pieper and Michael M\"{u}nter and Cornelia Holzhausen and Martin Ahrens and Christian Idel and Karl-Ludwig Bruchhage and Anke Leichtle and Peter K\"{o}nig and Gereon H\"{u}ttmann and Hinnerk Schulz-Hildebrandt},

url = {http://opg.optica.org/boe/abstract.cfm?URI=boe-13-6-3211},

doi = {10.1364/BOE.456104},

year  = {2022},

date = {2022-06-01},

urldate = {2022-06-01},

journal = {Biomed. Opt. Express},

volume = {13},

number = {6},

pages = {3211--3223},

publisher = {OSA},

abstract = {In the imaging of airway tissue, optical coherence tomography (OCT) provides cross-sectional images of tissue structures, shows cilia movement and mucus secretion, but does not provide sufficient contrast to differentiate individual cells. By using fast sequences of microscopic resolution OCT (mOCT) images, OCT can use small signal fluctuations to overcome lack in contrast and speckle noise. In this way, OCT visualizes airway morphology on a cellular level and allows the tracking of the dynamic behavior of immune cells, as well as mucus transport and secretion. Here, we demonstrate that mOCT, by using temporal tissue fluctuation as contrast (dynamic mOCT), provides the possibility to study physiological and pathological tissue processes in\ vivo.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{10.1167/tvst.11.5.28,

title = {Dynamic Contrast Microscopic Optical Coherence Tomography As a Novel Method for Assessing Corneal Epithelium During Exposure to Benzalkonium Chloride},

author = {Gwen Musial and Tabea Kohlfaerber and Martin Ahrens and Hinnerk Schulz-Hildebrandt and Philipp Steven and Gereon H\"{u}ttmann},

url = {https://doi.org/10.1167/tvst.11.5.28},

doi = {10.1167/tvst.11.5.28},

issn = {2164-2591},

year  = {2022},

date = {2022-01-01},

urldate = {2022-01-01},

journal = {Translational Vision Science \& Technology},

volume = {11},

number = {5},

pages = {28-28},

abstract = { Microscopic optical coherence tomography (mOCT) has an imaging resolution of 1 µm in all voxel dimensions, but individual epithelial cells are difficult to resolve due to lack of scattering contrast. Adding dynamic contrast processing to mOCT (dmOCT) results in color images that enable visualization of individual cells and possibly give information on cellular function via the calculation of a motility coefficient. We propose this technique as a novel method of evaluating the ocular surface after exposure to a toxic chemical, benzalkonium chloride (BAK). Ex vivo cross-section images were acquired with a custom-built, frequency-domain mOCT system. Eyes were explanted from healthy adult C57BL/6 mice and imaged every 30 minutes with five sets of dmOCT scans at each imaging time. Total epithelium and stroma thicknesses were measured from a single mOCT B-scan, and measures of color changes (hue) and the motility coefficient were acquired from dmOCT scans. After 30-minute exposures to 0.005% BAK, local motility decreased and total epithelium thickness increased compared to controls. For basal epithelium cells, local motility decreased after 60-minute exposures, and the hue shifted red after 90-minute exposures. Stroma thickness did not significantly swell until 150-minute exposures to BAK. dmOCT allows us to view the behavior of the cornea epithelium under toxic stress due to BAK, revealing parallel swelling of the extracellular matrix and changes in local subcellular motion. The evaluation of the cornea epithelium using dmOCT is helpful to our understanding of the toxic effects of BAK. },

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Munter:21,

title = {Microscopic optical coherence tomography (mOCT) at 600 kHz for 4D volumetric imaging and dynamic contrast},

author = {Michael M\"{u}nter and Mario Pieper and Tabea Kohlfaerber and Ernst Bodenstorfer and Martin Ahrens and Christian Winter and Robert Huber and Peter K\"{o}nig and Gereon H\"{u}ttmann and Hinnerk Schulz-Hildebrandt},

url = {http://www.osapublishing.org/boe/abstract.cfm?URI=boe-12-10-6024},

doi = {10.1364/BOE.425001},

year  = {2021},

date = {2021-10-01},

urldate = {2021-10-01},

journal = {Biomed. Opt. Express},

volume = {12},

number = {10},

pages = {6024--6039},

publisher = {OSA},

abstract = {Volumetric imaging of dynamic processes with microscopic resolution holds a huge potential in biomedical research and clinical diagnosis. Using supercontinuum light sources and high numerical aperture (NA) objectives, optical coherence tomography (OCT) achieves microscopic resolution and is well suited for imaging cellular and subcellular structures of biological tissues. Currently, the imaging speed of microscopic OCT (mOCT) is limited by the line-scan rate of the spectrometer camera and ranges from 30 to 250 kHz. This is not fast enough for volumetric imaging of dynamic processes in vivo and limits endoscopic application. Using a novel CMOS camera, we demonstrate fast 3-dimensional OCT imaging with 600,000 A-scans/s at 1.8\ textmum axial and 1.1 textmum lateral resolution. The improved speed is used for imaging of ciliary motion and particle transport in ex vivo mouse trachea. Furthermore, we demonstrate dynamic contrast OCT by evaluating the recorded volumes rather than en face planes or B-scans. High-speed volumetric mOCT will enable the correction of global tissue motion and is a prerequisite for applying dynamic contrast mOCT in vivo. With further increase in imaging speed and integration in flexible endoscopes, volumetric mOCT may be used to complement or partly replace biopsies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/rcs.2327,

title = {Instrument Localization for Endovascular Aneurysm Repair \textendash Comparison of two methods based on Tracking Systems or using Imaging},

author = {Sonja J\"{a}ckle and Annkristin Lange and Ver\'{o}nica Garc\'{i}a-V\'{a}zquez and Tim Eixmann and Florian Matysiak and Malte Maria Sieren and Marco Horn and Hinnerk Schulz-Hildebrandt and Gereon H\"{u}ttmann and Floris Ernst and Stefan Heldmann and Torben P\"{a}tz and Tobias Preusser},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/rcs.2327},

doi = {https://doi.org/10.1002/rcs.2327},

year  = {2021},

date = {2021-09-04},

journal = {The International Journal of Medical Robotics and Computer Assisted Surgery},

volume = {n/a},

number = {n/a},

pages = {e2327},

abstract = {Abstract Background In endovascular aortic repair (EVAR) procedures, medical instruments are currently navigated with a two-dimensional imaging based guidance requiring X-rays and contrast agent. Methods Novel approaches for obtaining the three-dimensional instrument positions are introduced. First, a method based on fiber optical shape sensing, one electromagnetic sensor and a preoperative computed tomography (CT) scan is described. Second, an approach based on image processing using one 2D fluoroscopic image and a preoperative CT scan is introduced. Results For the tracking based method, average errors from 1.81 to 3.13 mm and maximum errors from 3.21 to 5.46 mm were measured. For the image-based approach, average errors from 3.07 to 6.02 mm and maximum errors from 8.05 to 15.75 mm were measured. Conclusion The tracking based method is promising for usage in EVAR procedures. For the image-based approach are applications in smaller vessels more suitable, since its errors increase with the vessel diameter. This article is protected by copyright. All rights reserved.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}