Project Suggestions 2012/13 ___________________________ Here are some projects suggestions for this year. Have a look at my home page http://www.cs.ucl.ac.uk/staff/d.alexander or my group's website http://cmic.cs.ucl.ac.uk/mig to get an idea of other work going on; I am happy to discuss projects in any of those areas too. Models of dispersion in capillary networks ========================================== The project will construct and evaluate mathematical and computational models of the MRI signal from water molecules in blood flowing through capillary networks. It contributes to the broader research program of the Microstructure Imaging Group: cmic.cs.ucl.ac.uk/mig. Diffusion-weighted MRI holds great promise as a non-invasive diagnostic probe in cancer imaging. Blood flow in capillaries (the intra-voxel incoherent motion or IVIM effect) is a significant confound that complicates its practical application. However, modelling the effect potentially allows us to exploit diffusion-weighted imaging in cancer more effectively and may even provide additional information that is currently discarded. The project takes the first steps towards this by constructing candidate mathematical models and validating them against computer simulations. With Becky Shipley (UCL Dept. Mechanical Engineering) Cortical grey matter segmentation using diffusion MRI ===================================================== Segmenting the cortex of the brain in MRI images in a consistent and reliable way is a key challenge in neuroscience and neurology, because it enables meaningful comparisons of brain function across individuals. For example, to make statements about how two individuals execute a particular cognitive task, we need to be able to say with confidence which parts of the brain are active during the task. Recently we have derived new measurements from diffusion MRI that appear to separate the brain into functionally distinct areas. The aim of this project is to start to exploit this new information by combining those measurements with state of the art unsupervised learning and clustering algorithms to provide a brain segmentation with more precision and complexity than achievable by any existing approach. With Zoltan Nagy and Marty Sereno from UCL's Institute of Neurology Image-based diagnosis of multiple sclerosis =========================================== This project will use classification techniques from machine learning to make diagnoses of multiple sclerosis from brain images. UCL's institue of neurology has large databases of images from multiple-sclerosis patients and normal controls that we can use to train classifiers. More accurate diagnosis from imaging will have a direct impact on quality of life of these patients by expediting decisions about which treatments they should receive. Previous work has managed to get around 80% correct diagnosis using machine learning techniques, but the features the algorithms learn from are manually defined so expensive to obtain. This project will look at learning from much more directly obtainable image features aiming for a truly automated computer assisted diagnosis system. With Olga Ciccarelli from UCL's Institute of Neurology Stochastic optimization inspired by biological foraging models ============================================================== Stochastic optimization techniques, such as simulated annealing, genetic algorithms, self-organizing migratory algorithms (SOMA), and differential evolution, avoid problems of local minima that confound gradient descent algorithms. They are often the only viable techniques for minimizing high dimensional functions with complex topology. Many of these algorithms maintain a population of candidate solutions, which migrate over the search space in various ways. For example, the SOMA algorithm uses an analogy of herding cattle, which migrate towards rich areas of pasture. The precise mechanism of the migration determines the efficiency of the algorithm and the SOMA strategy proves consistently effective in a diverse range of problems. The aim of this project is to test a range of alternative biologically inspired migration strategies to improve the efficiency of the search. Cancer grading from histology ============================= This project aims to automate the process of cancer grading using image processing, computer vision and machine learning techniques. The standard way to diagnose cancer, and to determine how malignant a particular tumour is, is through biopsy and histology: a small piece of tumour is extracted from the patient; a pathologist looks at it under a microscope and decides, from the cellular make-up of the tissue, the nature of the tumour and thus the appropriate treatment. We will aim here to automate the pathologist's process of grading the cancer from the microscope image. We have lots of data to train and test classifiers. A key part of the project however will be to determine what are the most important image features required to maximize classification performance. With Laura Panagiotaki from UCL's Centre for Medical Image Computing