PREMATURE INFANT BLOOD VESSEL SEGMENTATION OF RETINAL IMAGES BASED ON HYBRID METHOD FOR THE DETERMINATION OF TORTUOSITY

For the retinal blood vessels segmentation, we used a method, which is based on the morphological operations. The output of this process is extracted retinal binary image, where is situated main blood vessels. In this paper is used dataset of images (2800 images) from device RetCam3. Before applying the image processing, it was selected 30 images with diagnosed pre-plus diseases, and it is divided into two groups with low contrast and good contrast images. In the next part of the analysis, it was analyzing and showing blood vessels with tortuosity. Tortuosity is a symptom of ROP (retinopathy of prematurity). The clinical physicians evaluate tortuosity by visual comparison of the retinal images images. For this reason, it was suggested model which can automatically indicate the tortuosity of the retinal blood vessels by setting a threshold of the blood vessels curvature

The Algorithm for Automatic Detection and Tortuosity Assessment of Retinal Blood Vessels

Import 03/11/2016Cílem této bakalářské práce je vytvořit algoritmus pro automatizovanou detekci cévního řečiště a algoritmus pro výpočet a hodnocení tortuozity. Klíčovými místy této práce jsou návrh a realizace již zmíněných algoritmů a návrh algoritmu pro výpočet objemu cév. Vytvořené algoritmy byly testovány na datasetu snímků sítnice nedonošených dětí, který byl poskytnut v anonymní podobě Centrem pro děti s vadami zraku Oční kliniky Fakultní nemocnice v Ostravě. Výstupem této práce je grafické uživatelské rozhraní vytvořené v MATLABU.TThe aim of this thesis is created algorithm for automatic detection of blood vessels and algorithm for calculation and evaluation of tortuosity. The key area of this aim are design and implementation the previous algorithms and design of algorithm for calculation volume of blood vessels. The algorithms were tested at the dataset of retinal image of the prematurity which is provided in anonymous form by Ophthalmologic clinic in Ostrava. Output of the thesis is graphic user interface. It was created at MATLAB.450 - Katedra kybernetiky a biomedicínského inženýrstvívýborn

Automatic Vessel Segmentation in Wide-field Retina Images of Infants with Retinopathy of Prematurity

The earliest signs of Retinopathy of Prematurity (ROP) are tortuosity and dilation of retinal vessels. Such vascular changes are considered of primary importance for the diagnosis and the follow-up of the disease. However, a widely accepted computerized system for their quantitative measurement is still missing. Images taken from a preterm baby's eye are often low-contrast, noisy, and blurred. Algorithms that have been successfully applied to analyze adult retinal images do not work well in ROP images. We propose here a novel method for the automatic extraction of vessel centerline in wide-field ROP retinal images, based on a sparse tracking scheme. After a set of seed points is identified all over the image, vessels are traced by connecting those seeds by means of minimum cost paths, whose weights depend on similarity features and alignment evaluated by a custom line operator. The performance of the method was assessed on a dataset of 20 images acquired with the RetCam fundus camera. A sensitivity of 0.78 and a false detection rate of 0.15 were obtained with respect to manual ground truth reference

Incidenza di forma e dimensione delle immagini nella stima della tortuosità dei vasi in immagini retiniche

Lo scopo della mia tesi è stato quello di valutare l'incidenza della forma (circolare o rettangolare) e della dimensione di ROI al fine di stimare la tortuosità dei vasi retinici di neonati prematuri. Infatti, un aumento di tale parametro è indice che il soggetto è a rischio ROP. Per diagnosticare in maniera corretta la patologia, sebbene richieda più tempo e più fatica, è necessario l'utilizzo del tracciamento manuale preferibilmente con finestre rettangolari e aventi grande estension