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1

Retinal vasculature segmentation and measurement framework for color fundus and SLO images

Pachade Samiksha, Porwal Prasanna, Kokare Manesh, Giancardo Luca, Meriaudeau Fabrice

Biocybernetics and Biomedical Engineering

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2020

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Vol. 40, no. 3

865--900

EN

The change in vascular geometry is an indicator of various health issues linked with vision and cardiovascular risk factors. Early detection and diagnosis of these changes can help patients to select an appropriate treatment option when the disease is in its primary phase. Automatic segmentation and quantification of these vessels would decrease the cost and eliminate inconsistency related to manual grading. However, automatic detection of the vessels is challenging in the presence of retinal pathologies and non-uniform illumination, two common occurrences in clinical settings. This paper presents a novel framework to address the issue of retinal blood vessel detection and width measurement under these challenging circumstances and also on two different imaging modalities: color fundus imaging and Scanning Laser Ophthalmoscopy (SLO). In this framework, initially, vessel enhancement is done using linear recursive filtering. Then, a unique combination of morphological operations, background estimation, and iterative thresholding are applied to segment the blood vessels. Further, vessel diameter is estimated in two steps: firstly, vessel centerlines are extracted using the graph-based algorithm. Then, vessel edges are localized from the image profiles, by utilizing spline fitting to obtain vascular orientations and then finding the zero-crossings. Extensive experiments have been carried out on several publicly accessible datasets for vessel segmentation and diameter measurement, i.e., DRIVE, STARE, IOSTAR, RC-SLO and REVIEW dataset. Results demonstrate the competitive and comparable performance than earlier methods. The encouraging quantitative and visual performance of the proposed framework makes it an important component of a decision support system for retinal images.

2

Polynomial modeling of retinal vessels for tortuosity measurement

Chetia Sanyukta, Nirmala S. R.

Biocybernetics and Biomedical Engineering

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2019

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Vol. 39, no. 2

512--525

EN

Tortuosity is one of the micro vascular change that is observed in many retinopathies. Its early detection can prevent the progression of various retinopathies to a critical stage at which a person may become blind. Here, we propose a novel method for the measurement of tortuosity by polynomial modeling of retinal vessels for the analysis of hypertensive retinopathy. The proposed method is tested on a set of 30 arteries and 30 veins vessel images collected from the Retinal Vessel Tortuosity Dataset (RET-TORT). Also, 90 vessel segments from Digital Retinal Images for Vessel Extraction (DRIVE) and 149 vessel segments from High Resolution Fundus (HRF) databases are used for tortuosity evaluation. The experimental results demonstrate that the order of the polynomial increases with the increase in the tortuosity of the blood vessels. Hence, the order of the polynomial can be used as a parameter to classify vessels as non-tortuous and tortuous. The results of the method are also evaluated subjectively and the inter-rater agreement analysis is made by using Fleiss Kappa index. The Spearman's rank order correlation coefficient is used to analyze the correlation between the ranking provided by the expert in the RET-TORT database and the ranking obtained by the proposed method. The results demonstrate that this method is capable of evaluating the tortuosity and classify vessel segments into non-tortuous or tortuous effectively.

3

Modeling of temperature field inside the tissue with a blood vessel using the BEM-FDM algorithm

Majchrzak E., Borowska J., Klekot J., Tarasek D.

Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej

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2012

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Vol. 11, nr 4

85-92

EN

The thermal interactions between the blood vessel and surrounding biological tissue are analyzed. The tissue temperature is described by the Pennes equation, while the equation determining the change of blood temperature along the blood vessel is formulated on the basis of adequate energy balance. These equations are coupled by a boundary condition given at the blood vessel wall. The problem is solved using the hybrid algorithm, this means the temperature field in biological tissue is determined by means of the boundary element method (BEM), while the blood temperature is determined by means of the finite difference method (FDM). In the final part the examples of computations are presented.

4

Automatic graph cut based segmentation of retinal optic disc by incorporating blood vessel compensation

Salazar-Gonzalez A., Li Y, Liu X.

Journal of Artificial Intelligence and Soft Computing Research

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2012

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Vol. 2, No. 3

235--245

EN

Glaucoma is one of the main causes of blindness worldwide. Periodical retinal screening is highly recommended in order to detect any sign of the disease and apply the appropriated treatment. Different systems for the analysis of retinal images have been designed in order to assist this process. The segmentation of the optic disc is an important step in the development of a retinal screening system. In this paper we present an unsupervised method for the segmentation of the optic disc. The main obstruction in the optic disc segmentation process is the presence of blood vessels breaking the continuity of the object. While many other methods have addressed this problem trying to eliminate the vessels, we have incorporated the blood vessel information into our formulation. The blood vessels inside of the optic disc are used to give continuity to the object to segment. Our approach is based on the graph cut technique, where the graph is constructed by considering the relationship between neighbouring pixels and by the likelihood of them belonging to the foreground and background from prior information. Our method was tested on two public datasets, DIARETDB1 and DRIVE. The performance of our method was measured by calculating the overlapping ratio (Oratio), sensitivity and the mean absolute distance (MAD) with respect to the manually labeled images.

5

Numerical modeling of heat transfer in a single blood vessel and surrounding biological tissue

Majchrzak E., Tarasek D.

Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej

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2010

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Vol. 9, nr 2

145-152

EN

The thermal interactions between the single blood vessel and surrounding biological tissue are analyzed. The temperature in the tissue is described by the Pennes equation, while the equation determining the change of blood temperature along the blood vessel is formulated on the basis of adequate energy balance. These equations are coupled by boundary condition given at the blood vessel wall. There are two models considered here in terms of blood vessel types. First is the supplying vessel model and the other one is traversing vessel model. Both are distinguished in the computations. The solution of the problem has been provided by means of finite difference method.

6

Ocena metody zbiorów poziomicowych stosowanych do segmentacji trójwymiarowych obrazów fantomów cyfrowych oraz obrazów naczyń krwionośnych mózgu TOF-SWI rezonansu magnetycznego

Strzelecki M., Materka A., Kociński M., Szczypiński P., Deistung A., Reichenbach J.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

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2010

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Vol. 16, nr 2

167-172

PL

W pracy zbadano dokładność metody segmentacji level set stosowanej do analizy trójwymiarowych obrazów fantomów przedstawiających fragmenty naczyń oraz układ drzew krwionośnych. Badano przydatność metody do detekcji cienkich naczyń (o średnicy mniejszej niż rozmiar woksela obrazu) oraz jej odporność na zakłócenia. Oceny metody dokonano za pomocą obiektywnej miary ilościowej opisującej dokładność segmentacji. Metodę level set wykorzystano również do segmentacji rzeczywistych trójwymiarowych obrazów TOF-SWI (Time Of Flight and Susceptibility Weighted Imaging) rezonansu magnetycznego naczyń krwionośnych mózgu wraz z metodą Sato, wykorzystującą filtrację wieloskalową. Wstępne wyniki, w postaci trójwymiarowych modeli naczyń krwionośnych, są obiecujące. W pracy przedstawiono kierunki dalszych badań prowadzących do uzyskania dokładniejszych modeli układu krwionośnego, zwłaszcza dla naczyń o małych średnicach.

EN

The objective of this work is to evaluate performance of the level set approach applied to segmentation of 3D images of computer-simulated blood-vessel phantoms and artificial vascular trees. The segmentation of thin vessels with diameter smaller than voxel size and influence of noise on segmentation results, were studied. Quantitative measures of segmentation accuracy were used for the methods evaluation. The level set technique was also used for segmentation of 3D TOF-SWI MR (Time Of Flight and Susceptibility Weighted Magnetic Resonance Imaging) brain vessels images. Also, the multiscale filtering approach was applied. Preliminary results in the form of 3D vein and artery models are promising. Further work aimed at more accurate modeling of brain vasculature, focused on thin vessels detection is also addressed.

7

Wpływ ładunku elektrycznego na potencjał elektrokinetyczny na granicy faz: proteza naczyń krwionośnych-krew

Łowkis B., Zboromirska-Wnukiewicz B., Gryzło K.

Przegląd Elektrotechniczny

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2008

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R. 84, nr 10

108-111

PL

W pracy przedstawiono wpływ ładunku elektrycznego na adhezję krwinek płytkowych i poziom białka całkowitego. Wyznaczono potencjał zeta protez nieelektryzowanych i elektretów w roztworach o różnych pH. Zbadano wpływ czasu na potencjał zeta krwi ludzkiej. Określono zachowanie się potencjału zeta na granicy proteza naczyń krwionośnych-krew w funkcji czasu.

EN

Presented work describes influence of charge on blood platelets adhesion and complete protein level. Zeta potential of prostheses and electrets in solutions with different pH was determined. The influence of time on zeta potential of human blood was examined. Also behavior of zeta potential in function of time between blood vessel prosthesis – blood was described.

8

Numerical simulation of pulsating blood flow through stenosed vessel

Kohge K., Minemura K.

International Journal of Applied Mechanics and Engineering

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2003

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Vol. 8, no. spec.

155-161

EN

In connection with blood flow in stenosed blood vessels, Ojha and his co-workers have been measured pulsating flows in rigged pipes with a contraction using kerosene. The experiment, however, leaves something to be desired, for example, the pressure fluctuation relevant to the pulsating flow velocity is entirely unknown. To make clear the mechanism of the pulsating flow in the stenosed pipes, the flow is numerically simulated, in this paper, using a finite difference method with CIP scheme. Obtained axial velocity distributions and thickness of separation region are confirmed with Ojha's experimental results. Resultant flow brings about large periodical change of wall stress in the downstream and of pressure at the contraction, respectively, suggesting that the flow behaviour relates closely with arterial diseases.

9

Numerical model of heat transfer between blood vessel and biological tissue

Majchrzak E., Mochnacki B.

Computer Assisted Mechanics and Engineering Sciences

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1999

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Vol. 6, No. 3-4

439--447

EN

The thermal processes proceeding within a perfused tissue in the presence of a vessel are considered. The Pennes bio-heat transfer equation determines the steady state temperature field in tissue sub-domain, while the ordinary differential equation resulting from the energy balance describes the change of blood temperature along the vessel. The coupling of above equations results from the boundary condition given on the blood vessel wall. The problem is solved using the combined numerical algorithm, in particular the boundary element method (for the tissue sub-domain) and the finite differences method (for blood vessel sub-domain).