Author
Georg Michelson
Other affiliations: Yunnan Agricultural University
Bio: Georg Michelson is an academic researcher from University of Erlangen-Nuremberg. The author has contributed to research in topics: Glaucoma & Retinal. The author has an hindex of 33, co-authored 175 publications receiving 4023 citations. Previous affiliations of Georg Michelson include Yunnan Agricultural University.
Topics: Glaucoma, Retinal, Optic nerve, Blood pressure, Fundus (eye)
Papers published on a yearly basis
Papers
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TL;DR: A method to reduce calculation time, achieve high accuracy, and increase sensitivity compared to the original Frangi method is presented and a new high resolution fundus database is proposed to compare it to the state-of-the-art algorithms.
Abstract: One of the most common modalities to examine the human eye is the eye-fundus photograph. The evaluation of fundus photographs is carried out by medical experts during time-consuming visual inspection. Our aim is to accelerate this process using computer aided diagnosis. As a first step, it is necessary to segment structures in the images for tissue differentiation. As the eye is the only organ, where the vasculature can be imaged in an in vivo and noninterventional way without using expensive scanners, the vessel tree is one of the most interesting and important structures to analyze. The quality and resolution of fundus images are rapidly increasing. Thus, segmentation methods need to be adapted to the new challenges of high resolutions. In this paper, we present a method to reduce calculation time, achieve high accuracy, and increase sensitivity compared to the original Frangi method. This method contains approaches to avoid potential problems like specular reflexes of thick vessels. The proposed method is evaluated using the STARE and DRIVE databases and we propose a new high resolution fundus database to compare it to the state-of-the-art algorithms. The results show an average accuracy above 94% and low computational needs. This outperforms state-of-the-art methods.
423 citations
TL;DR: SLDF enables the visualization of perfused vessels of the jux-tapapillary retina and the optic nerve head in high resolution by two-dimensional mapping of the optical Doppler shift and a reproducible evaluation of capillary blood flow.
Abstract: SUMMARYPurposeThe objective of this study is to present the reliability and validity of scanning laser Doppler flowmetry (SLDF) performing a high-definition topography of perfused vessels of the retina and the optic nerve head with simultaneous evaluation of blood flow.MethodsThe examination of bloo
259 citations
TL;DR: It could be shown that the approach presented is suitable for automated diagnosis and screening of glaucoma and is validated by comparing the performance of different classifiers on data from a case-control study with contours of the optic nerve head manually outlined by an experienced ophthalmologist.
181 citations
TL;DR: In POAG, optic nerve head blood flow and juxtapapillary blood flow were significantly decreased and the decrease of neuroretinal rim area blood flow did significantly correlate with C/D.
Abstract: PURPOSE The objective of this study is to evaluate capillary blood flow of the juxtapapillary retina and neuroretinal rim area in primary open angle glaucoma (POAG) by a new noninvasive method performing a high-definition topography of perfused vessels of the retina and the optic nerve head with simultaneous evaluation of blood flow. METHODS Juxtapapillary retinal and neuroretinal rim area blood flow were measured by scanning laser Doppler flowmetry (SLDF). This new technique is a combination of a laser Doppler flowmeter with a scanning laser system by which the retinal perfusion is simultaneously quantified in 16,000 sites of a retinal area of 2.7 x 0.7 mm. In study I, retinal and optic nerve head blood flow were evaluated by SLDF in 43 patients with POAG and 43 healthy individuals. The mean age of the POAG group was 56 +/- 12 years and of the control group 42 +/- 15 years. In study II, age-matched normals (n = 21) were compared with glaucoma eyes with topical therapy (n = 30) and with glaucoma eyes without topical therapy (n = 16). RESULTS In study I, the eyes with POAG had an average cup/disc ratio (C/D) of 0.75 +/- 0.20, with an average mean defect of the visual field of 5.3 +/- 5.4 dB. The actual intraocular pressure was 17.8 +/- 4.18 mm Hg in the POAG group and 15.45 +/- 1.82 mm Hg in the control group. For statistical analysis, two age-matched groups of 28 normal eyes of 28 persons with 27 glaucomatous eyes of 27 patients were compared. In normals the blood flow of the neuroretinal rim area was significantly higher than that of the juxtapapillary retinal area (+7.73%, p < 0.01). In POAG both juxtapapillary retinal blood flow and neuroretinal rim area blood flow were significantly decreased compared to an age-matched control group: neuroretinal rim area flow -71% and juxtapapillary retina flow -49%. The decrease of neuroretinal rim area blood flow did significantly correlate with C/D. We found no correlation between reduction of juxtapapillary retinal blood flow and C/D or mean defect. Both glaucoma eyes with and glaucoma eyes without topical therapy showed significant decreased juxtapapillary blood flow compared to normals. We found no significant difference in the juxtapapillary blood flow between glaucoma eyes with and without topical therapy. CONCLUSIONS In POAG, optic nerve head blood flow and juxtapapillary blood flow were significantly decreased.
170 citations
20 Jun 2013
TL;DR: A no-reference quality metric to quantify image noise and blur and its application to fundus image quality assessment is presented, which correlates reasonable to a human observer, indicating high agreement to human visual perception.
Abstract: Fundus imaging is the most commonly used modality to collect information about the human eye background. Objective and quantitative assessment of quality for the acquired images is essential for manual, computer-aided and fully automatic diagnosis. In this paper, we present a no-reference quality metric to quantify image noise and blur and its application to fundus image quality assessment. The proposed metric takes the vessel tree visible on the retina as guidance to determine an image quality score. In our experiments, the performance of this approach is demonstrated by correlation analysis with the established full-reference metrics peak-signal-to-noise ratio (PSNR) and structural similarity (SSIM). We found a Spearman rank correlation for PSNR and SSIM of 0.89 and 0.91. For real data, our metric correlates reasonable to a human observer, indicating high agreement to human visual perception.
155 citations
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TL;DR: This scientific statement provides an overview of the evidence on vascular contributions to cognitive impairment and dementia and provides evidence that subcortical forms of VCI with white matter hyperintensities and small deep infarcts are common and risk markers for VCI are the same as traditional risk factors for stroke.
Abstract: Background and Purpose—This scientific statement provides an overview of the evidence on vascular contributions to cognitive impairment and dementia. Vascular contributions to cognitive impairment ...
2,731 citations
TL;DR: The potential role of OBf in glaucoma is discussed and how a disturbance of OBF could increase the optic nerve's sensitivity to IOP is discussed.
1,525 citations
TL;DR: This review will examine how vascular damage disrupts vital homeostatic interactions in brain health, focusing on the hemispheric white matter, a region at heightened risk for vascular damage, and on the interplay between vascular factors and Alzheimer's disease.
1,284 citations
TL;DR: A review of recent advances in medical imaging using the adversarial training scheme with the hope of benefiting researchers interested in this technique.
1,053 citations
University of Milano-Bicocca1, University of Paris2, University of Brescia3, University of Bologna4, University of Lausanne5, Queen Mary University of London6, Ghent University7, University of Barcelona8, University of Glasgow9, Istanbul University10, Katholieke Universiteit Leuven11, Hannover Medical School12, University of Manchester13, University of Oslo14, Joseph Fourier University15, Gdańsk Medical University16, University of Copenhagen17, University of Münster18, University of Valencia19, Complutense University of Madrid20, University of Erlangen-Nuremberg21, Maastricht University22, University of Amsterdam23, University of Milan24
TL;DR: The objective of this study was to establish a baseline for the design of a systematic literature review of this type of treatment for high blood pressure using a simple, straightforward, and scalable procedure.
Abstract: Abbreviations ACE: angiotensin-converting enzyme; BP: blood pressure; DBP: diastolic blood pressure; eGFR: estimated glomerular filtration rate; ESC: European Society of Cardiology; ESH: European Society of Hypertension; ET: endothelin; IMT: carotid intima-media thickness; JNC: Joint National Commit
976 citations