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Automated Image Detection of Retinal Pathology

ical morphology and curvature evaluation, IEEE Transactions on Image Processing, 10, 1010, 2001.

[11]Cesar, Jr., R.M. and Jelinek, H.F., Segmentation of retinal fundus vasculature in non-mydriatic camera images using wavelets, in Angiography and Plaque Imaging: Advanced Segmentation Techniques, J. Suri and T. Laxminarayan, eds., CRC Press, 193–224, 2003.

[12]McQuellin, C.P., Jelinek, H.F., and Joss, G., Characterisation of fluorescein angiograms of retinal fundus using mathematical morphology: A pilot study, in 5th International Conference on Ophthalmic Photography, Adelaide, 2002, 152.

[13]Wong, T.Y., Rosamond, W., Chang, P.P., et al., Retinopathy and risk of congestive heart failure, Journal of the American Medical Association, 293(1), 63, 2005.

[14]Pedersen, L., Ersbøll, B., Madsen, K., et al., Quantitative measurement of changes in retinal vessel diameter in ocular fundus images, Pattern Recognition Letters, 21(13-14), 1215, 2000.

[15]Hart, W.E., Goldbaum, M., Cotˆe,´ B., et al., Measurement and classification of retinal vascular tortuosity, International Journal of Medical Informatics, 53, 239, 1999.

[16]Jelinek, H.F., Leandro, J.J.G., Cesar, Jr., R.M., et al., Classification of pathology in diabetic eye disease, in WDIC2005 ARPS Workshop on Digital Image Computing, Brisbane, Australia, 2005, 9–13.

[17]Yang, G. and Stewart, C.V., Covariance-driven mosaic formation from sparsely-overlapping image sets with application to retinal image mosaicing, in IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR), 2004, vol. 1, 804–810.

[18]Zana, F. and Klein, J.C., A multimodal registration algorithm of eye fundus images using vessels detection and hough transform, IEEE Transactions on Medical Imaging, 18, 419, 1999.

[19]Hill, R., Retina identification, in Biometrics: Personal Identification in Networked Society, A.K. Jain, R. Bolle, and S. Pankanti, eds., Kluwer Academic Publishers, 123–141, 1998.

[20]Cree, M.J., Leandro, J.J.G., Soares, J.V.B., et al., Comparison of various methods to delineate blood vessels in retinal images, in Proc. of the 16th National Congress of the Australian Institute of Physics, Canberra, Australia, 2005, available from: http://aipcongress2005.anu.edu.au/index.php?req= CongressProceedings. Cited May 2006.

[21]Niemeijer, M., Staal, J.J., van Ginneken, B., et al., Comparative study of retinal vessel segmentation methods on a new publicly available database, in Medical

Segmentation of Retinal Vasculature Using Wavelets

263

Imaging 2004: Image Processing, J.M. Fitzpatrick and M. Sonka, eds., San Diego, CA, 2004, vol. 5370 of Proc. SPIE, 648–656.

[22]Soares, J.V.B., Leandro, J.J.G., Cesar, Jr., R.M., et al., Retinal vessel segmentation using the 2-D Gabor wavelet and supervised classification, IEEE Transactions on Medical Imaging, 25, 1214, 2006.

[23]Mart´ınez-Perez,´ M.E., Hughes, A.D., Stanton, A.V., et al., Retinal blood vessel segmentation by means of scale-space analysis and region growing, in Medical Image Computing and Computer-assisted Intervention (MICCAI), 1999, 90– 97.

[24]Chaudhuri, S., Chatterjee, S., Katz, N., et al., Detection of blood vessels in retinal images using two-dimensional matched filters, IEEE Transactions on Medical Imaging, 8, 263, 1989.

[25]Hoover, A., Kouznetsova, V., and Goldbaum, M., Locating blood vessels in retinal images by piecewise threshold probing of a matched filter response,

IEEE Transactions on Medical Imaging, 19, 203, 2000.

[26]Jiang, X. and Mojon, D., Adaptive local thresholding by verification-based multithreshold probing with application to vessel detection in retinal images,

IEEE Transactions on Pattern Analysis and Machine Intelligence, 25(1), 131, 2003.

[27]Mendonc¸a, A.M. and Campilho, A., Segmentation of retinal blood vessels by combining the detection of centerlines and morphological reconstruction, IEEE Transactions on Medical Imaging, 25, 1200, 2006.

[28]Staal, J.J., Abramoff,` M.D., Niemeijer, M., et al., Ridge based vessel segmentation in color images of the retina, IEEE Transactions on Medical Imaging, 23(4), 501, 2004.

[29]Gabor, D., Theory of communication, Journal of the IEE, 93, 429, 1946.

[30]Rioul, O. and Vetterli, M., Wavelets and signal processing, IEEE Signal Processing Magazine, 8, 14, 1991.

[31]Goupillaud, P., Grossmann, A., and Morlet, J., Cycle-Octave and related transforms in seismic signal analysis, Geoexploration, 23, 85, 1984.

[32]Grossmann, A. and Morlet, J., Decomposition of hardy functions into square integrable wavelets of constant shape, SIAM Journal on Mathematical Analysis, 15, 723, 1984.

[33]Grossmann, A., Wavelet transforms and edge detection, in Stochastic Processes in Physics and Engineering, S. Albeverio, P. Blanchard, M. Hazewinkel, and L. Streit, eds., D. Reidel Publishing Company, 1988, 149–157.

[34]Mallat, S. and Hwang, W.L., Singularity detection and processing with wavelets, IEEE Transactions on Information Theory, 38(2), 617, 1992.

264

Automated Image Detection of Retinal Pathology

[35]Daubechies, I., Ten lectures on wavelets, Society for Industrial and Applied Mathematics, Philadelphia, PA, 1992.

[36]Costa, L.F. and Cesar, Jr., R.M., Shape analysis and classification: Theory and practice, CRC Press, 2001.

[37]Unser, M. and Aldroubi, A., A review of wavelets in biomedical applications,

Proceedings of the IEEE, 84, 626, 1996.

[38]Van De Ville, D., Blu, T., and Unser, M., Integrated wavelet processing and spatial statistical testing of fMRI data, NeuroImage, 23(4), 1472, 2004.

[39]Antoine, J.P., Carette, P., Murenzi, R., et al., Image analysis with twodimensional continuous wavelet transform, Signal Processing, 31, 241, 1993.

[40]Murenzi, R., Ondelettes multidimensionelles et application a` l’analyse d’images, PhD thesis, Universite´ Catholique de Louvain, 1990.

[41]Ferrari, R.J., Rangayyan, R.M., Desautels, J.E.L., et al., Analysis of asymmetry in mammograms via directional filtering with Gabor wavelets, IEEE Transactions on Medical Imaging, 20, 953, 2001.

[42]Manjunath, B.S. and Ma, W.Y., Texture features for browsing and retrieval of image data, IEEE Transactions on Pattern Analysis and Machine Intelligence, 18(8), 837, 1996.

[43]Mallat, S. and Zhong, S., Characterization of signals from multiscale edges,

IEEE Transactions on Pattern Analysis and Machine Intelligence, 14(7), 710, 1992.

[44]Marr, D. and Hildreth, E., Theory of edge detection, Proceedings of the Royal Society of London. Series B, Biological Sciences, 207, 187, 1980.

[45]Argoul, F., Arneodo,´ A., Elezgaray, J., et al., Wavelet analysis of the selfsimilarity of diffusion-limited aggregates and electrodeposition clusters, Physical Review A, 41(10), 5537, 1990.

[46]Arneodo,´ A., Decoster, N., and Roux, S.G., A wavelet-based method for multifractal image analysis. I. Methodology and test applications on isotropic and anisotropic random rough surfaces, The European Physical Journal B, 15, 567, 2000.

[47]Farge, M., Wavelet transforms and their applications to turbulence, Annual Review of Fluid Mechanics, 24, 395, 1992.

[48]Antoine, J.P., Murenzi, R., and Vandergheynst, P., Directional wavelets revisited: Cauchy wavelets and symmetry detection in patterns, Applied and Computational Harmonic Analysis, 6, 314, 1999.

[49]Gonzalez, R.C. and Woods, R.E., Digital Image Processing, Addison-Wesley, 2nd ed., 2002.

Segmentation of Retinal Vasculature Using Wavelets

265

[50]Antoine, J.P. and Murenzi, R., Two-dimensional directional wavelets and the scale-angle representation, Signal Processing, 52, 259, 1996.

[51]Lee, T.S., Image representation using 2D Gabor wavelets, IEEE Transactions on Pattern Analysis and Machine Intelligence, 18(10), 959, 1996.

[52]Daugman, J.G., Two-dimensional spectral analysis of cortical receptive field profiles, Vision Research, 20, 847, 1980.

[53]Marcelja,ˇ S., Mathematical description of the responses of simple cortical cells,

Journal of the Optical Society of America, 70(11), 1297, 1980.

[54]Daugman, J.G., Complete discrete 2-D Gabor transforms by neural networks for image analysis and compression, IEEE Transactions on Acoustics, Speech, and Signal Processing, 36(7), 1169, 1988.

[55]Krueger, V. and Sommer, G., Gabor wavelet networks for face processing, Journal of the Optical Society of America, 19, 1112, 2002.

[56]Feris, R.S., Krueger, V., and Cesar, Jr., R.M., A wavelet subspace method for real-time face tracking, Real-Time Imaging, 10, 339, 2004.

[57]Sagiv, C., Sochen, N.A., and Zeevi, Y.Y., Gabor features diffusion via the minimal weighted area method, in Energy Minimization Methods in Computer Vision and Pattern Recognition (EMMCVPR), 2002.

[58]Chen, J., Sato, Y., and Tamura, S., Orientation space filtering for multiple orientation line segmentation, IEEE Transactions on Pattern Analysis and Machine Intelligence, 22, 417, 2000.

[59]Ayres, F.J. and Rangayyan, R.M., Performance analysis of oriented feature detectors, in Proc. of the 18th Brazilian Symposium on Computer Graphics and Image Processing (SIBGRAPI), IEEE Computer Society, 2005, 147– 154.

[60]Harrop, J.D., Taraskin, S.N., and Elliott, S.R., Instantaneous frequency and amplitude identification using wavelets: Application to glass structure, Physical Review E, 66(2), 026703, 2002.

[61]Duda, R.O., Hart, P.E., and Stork, D.G., Pattern Classification, John Wiley and Sons, 2001.

[62]Theodoridis, S. and Koutroumbas, K., Pattern Recognition, Academic Press, San Diego, CA, 1st ed., 1999.

[63]Dempster, A.P., Laird, N.M., and Rubin, D.B., Maximum likelihood from incomplete data via the EM algorithm, Journal of the Royal Statistical Society, Series B, 39(1), 1, 1977.

[64]Figueiredo, M.A.T. and Jain, A.K., Unsupervised learning of finite mixture models, IEEE Transactions on Pattern Analysis and Machine Intelligence, 24, 381, 2002.

266

Automated Image Detection of Retinal Pathology

[65]Leandro, J.J.G., Cesar, Jr., R.M., and Jelinek, H.F., Blood vessels segmentation in retina: Preliminary assessment of the mathematical morphology and of the wavelet transform techniques, in Proc. of the 14th Brazilian Symposium on Computer Graphics and Image Processing (SIBGRAPI), IEEE Computer Society, 2001, 84–90.

[66]Leandro, J.J.G., Soares, J.V.B., Cesar, Jr., R.M., et al., Blood vessels segmentation in non-mydriatic images using wavelets and statistical classifiers, in Proc. of the 16th Brazilian Symposium on Computer Graphics and Image Processing (SIBGRAPI), IEEE Computer Society Press, 2003, 262–269.

[67]Sofka, M. and Stewart, C.V., Retinal vessel centerline extraction using multiscale matched filters, confidence and edge measures, IEEE Transactions on Medical Imaging, 25, 1531, 2006.

[68]Cornforth, D.J., Jelinek, H.F., Leandro, J.J.G., et al., Development of retinal blood vessel segmentation methodology using wavelet transforms for assessment of diabetic retinopathy, Complexity International, 11, 2005, cited May 2006, http://www.complexity.org.au/ci/vol11/.

[69]Fawcett, T., An introduction to ROC analysis, Pattern Recognition Letters, 27, 861, 2006.

[70]Provost, F. and Fawcett, T., Robust classification for imprecise environments, Machine Learning, 42(3), 203, 2001.

[71]Hanley, J.A. and McNeil, B.J., The meaning and use of the area under a receiver operating characteristic (ROC) curve, Radiology, 143, 29, 1982.

[72]MATLAB, MATLAB website at MathWorks, 2006, cited May 2006, http:// www.mathworks.com/products/matlab.

[73]Free Software Foundation, GNU general public license, 1991, cited July 2006, http://www.gnu.org/copyleft/gpl.html.

[74]Vandergheynst, P. and Gobbers, J.F., Directional dyadic wavelet transforms: design and algorithms, IEEE Transactions on Image Processing, 11(4), 363, 2002.

[75]Malladi, R., Sethian, J.A., and Vemuri, B.C., Shape modeling with front propagation: A level set approach, IEEE Transactions on Pattern Analysis and Machine Intelligence, 17(2), 158, 1995.

[76]McInerney, T. and Terzopoulos, D., T-snakes: Topology adaptive snakes, Medical Image Analysis, 4, 73, 2000.

[77]Bowyer, K.W. and Phillips, P.J., eds., Empirical Evaluation Techniques in Computer Vision, IEEE Computer Society, 1998.

Segmentation of Retinal Vasculature Using Wavelets

267

[78]Lowell, J., Hunter, A., Steel, D., et al., Measurement of retinal vessel widths from fundus images based on 2-D modeling, IEEE Transactions on Medical Imaging, 23(10), 1196, 2004.

9

Determining Retinal Vessel Widths and

Detection of Width Changes

Kenneth H. Fritzsche, Charles V. Stewart, and Bardrinath Roysam

CONTENTS

 

9.1

Identifying Blood Vessels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

270

9.2

Vessel Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

270

9.3

Vessel Extraction Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

271

9.4

Can’s Vessel Extraction Algorithm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

271

9.5

Measuring Vessel Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

276

9.6

Precise Boundary Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

278

9.7

Continuous Vessel Models with Spline-Based Ribbons . . . . . . . . . . . . . . . . . . . . .

279

9.8

Estimation of Vessel Boundaries Using Snakes. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

288

9.9

Vessel Width Change Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

294

9.10

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

298

 

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

299

Detection of width changes in blood vessels of the retina may be indicative of eye or systemic disease. However, all fundus images, even those taken during a single sitting, are acquired at different perspective geometries, have different scales, and are difficult to manually compare side by side. This problem is increased for images acquired over time and is in no way lessened when different cameras are used as technology improves or patients change doctors. Indeed, even the method of image recording media has changed. In order to compare two images acquired at different times, automated techniques must be used to detect vessels, register images, and identify potential regions of blood vessel width change.

In order to detect vessel width change, vessels must first be identified in available digital images. Several methods for automated vessel detection exist, and this chapter discusses several and presents a method for parameterizing blood vessels in ribbonlike objects that provide continuous boundaries along the entire length of a vessel.

Once blood vessels are identified, these vessels can then be used to identify vessel intersections and bifurcations that are the basis for performing image registration. Once two images are registered and the blood vessels are continuously defined in

269

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Automated Image Detection of Retinal Pathology

each, a method for finding common vessels in the image and performing change detection is presented.

9.1Identifying Blood Vessels

The processes of separating the portions of a retinal image that are vessels from the rest of the image are known as vessel extraction (or tracing) and vessel segmentation. These processes are similar in goal but typically are distinct in process. Each have complications due to such factors as poor contrast between vessels and background; presence of noise; varying levels of illumination and contrast across the image; physical inconsistencies of vessels such as central reflex [1–5]; and the presence of pathologies. All these factors yield different results, both in terms of how the results are modeled and the actual regions identified. Different methods yield distinctly different results and even the same method will yield different results for images taken from the same patient in a single session. These differences become significant for images taken at different points in time as they could be mistaken as change. Methods used to determine the vessel boundaries should strive to lessen the frequency and severity of these inconsistencies.

9.2Vessel Models

Many models are used to describe and identify vessels in images. Most are based on detectable image features such as edges, cross-sectional profiles, or regions of uniform intensity. Edge models use algorithms that work by identifying vessel boundaries typically by applying an edge detection operator such as differential or gradient operators [6–8]; Sobel operators [9; 10]; Kirsch operators [11]; or first order Gaussian filters [12]. Cross-sectional models employ algorithms that attempt to find regions of the image that closely approximate a predetermined shape such as a half ellipse [13]; Gaussian [1; 14–19]; or 6th degree polynomial [20]. Algorithms that use local areas of uniform intensity generally employ thresholding [21; 22], relaxation [23], morphological operators [16; 24–26], or affine convex sets to identify ridges and valleys [27].

Blood vessel models can more generally be characterized as those that are boundary detection (or edge detection) based or those that are cross section or matchedfilter based. Depending on the intended application for the vessels detected, different aspects of the model may be more important. For vessel change detection, we decided that the most important aspect of the vessel model is the accurate and precise location of vessel boundaries.

Determining Retinal Vessel Widths and Detection of Width Changes

271

9.3Vessel Extraction Methods

Algorithms for identifying blood vessels in a retina image generally fall into two classes — those that segment vessel pixels and those that extract vessel information. Generally, segmentation is referred to as a process in which, for all pixels, certain characteristics of each pixel and its neighbors are examined. Then, based on some criteria, each pixel is determined to belong to one of several groups or categories. In retinal image segmentation, the simplest set of categories is binary — vessel or nonvessel (background). This is what we refer to as “vessel segmentation.” Techniques for segmentation include thresholding [21], morphological operations [16; 24–26; 28], matched filters [9; 15–17; 22; 29; 30], neural nets [31–33], FFTs [34], and edge detectors [6; 9; 11; 35; 36]. Segmentation algorithms generally produce binary segmentations, are computationally expensive and typically require further analysis to calculate morphometric information such as vessel width.

Extraction algorithms [1; 8; 12; 14; 18; 36–39] on the other hand, generally use exploratory techniques. They are faster computationally and usually determine useful morphometric information as part of the discovery process. They work by starting on known vessel points and “tracing” or “tracking” the vasculature structure in the image based on probing for certain vessel characteristics such as the vessel boundaries. Since the vessel boundaries are part of the discovery process, these algorithms generally contain information such as vessel widths, center points, and local orientation that can be used later in the change detection process. Many of these methods employ edge-centric models and are well suited for vessel change detection. For these reasons, we selected the exploratory algorithm in Section 9.4 as the basis for the change detection algorithm described in Section 9.9.

9.4Can’s Vessel Extraction Algorithm

Can’s vessel extraction (or “tracing”) algorithm [8] uses an iterative process of tracing the vasculature based on a localized model. The model is based on two physical properties of vessels — that vessels are locally straight and consist of two parallel sides. As such, it works by searching for two parallel vessel boundaries, found based on detection of two parallel, locally straight edges. The entire algorithm consists of two stages.

Stage 1 (seed point initialization): The algorithm analyzes the image along a coarse grid to gather samples for determining greyscale statistics (contrast and brightness levels) and to detect initial locations of blood vessels using greyscale minima. These minima are considered as “seed points” at which a tracing algorithm will be initiated. False seed points are filtered out by testing for the existence of a pair of sufficiently strong parallel edges around the minima. A seed point is filtered out if