The purpose of the research described in this dissertation is to develop new methods for automatic chromosome identification. In particular, I (1) develop a maximum likelihood hypothesis test that uses this multi-spectral information, together with conventional criteria, to select the best segmentation possibility, (2) use this likelihood function to combine chromosome segmentation and classification into a robust chromosome identification system, and (3) show that the proposed likelihood function can also be used as a reliable indicator of errors in segmentation, errors in classification, and the chromosomes anomalies that can be diagnosed with M-FISH imaging. I show that the proposed multispectral joint segmentation-classification method outperforms past grayscale segmentation methods in decomposing touching chromosomes. Furthermore, I show that it outperforms past M-FISH classification techniques that do not use segmentation information.
OBJECTIVESThis work investigated what improvements in chromosome analysis could be obtained by using M-FISH multi-spectral images. One aim of this work was to develop algorithms that could take full advantage of the multi-spectral information and to quantify their improvement over grayscale chromosome image analysis methods. In order to achieve effective segmentation and classification, I studied how to combine segmentation and classification to make both more accurate. Furthermore, this work examined how to use this multi-spectral information to detect automatically abnormalities in the chromosomes that could not be detected without such chromosome labeling.
CONTRIBUTIONSThe best approach for segmentation and classification of multi-spectral chromosome images is fundamentally different from the best approach for grayscale chromosome images. The additional information provided by multispectral chromosome images is useful for distinguishing touching and 2. This maximum likelihood test is used to propose a method that combines the task of locating and classifying chromosomes for improved performance in both tasks.3. The first two contributions in the dissertation are then used to achieve aberration scoring; that is, giving a score to each segment to indicate the likelihood of abnormalities in that image. 4
NOTATIONThis section gives the mathematical notation that is followed throughout the dissertation. I denote vectors with boldface and scalars with plain font. I use the function ( ) ⋅ p to denote a probability. Further, the functiondenotes the usual Gaussian probability density function. Thus the probability density function of a random vector x , with mean µ and covariance matrix Σ , is ( )
ORGANIZATIONThe structure of this dissertation is as follows. Chapter 2 introduces the features of chromosomes and chromosomes images and shows how these features
CHROMOSOMESChromosomes are the body's information carriers. They are the structures that contain genes, which store in strings of DNA all of the data necessary for an organism's development and maintenance. Chromosome...