Edward A. Ashton

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PURPOSE To evaluate the accuracy, reproducibility, and speed of two semiautomated methods for quantifying total white matter lesion burden in multiple sclerosis (MS) patients with respect to manual tracing and to other methods presented in recent literature. MATERIALS AND METHODS Two methods involving the use of MRI for semiautomated quantification of(More)
A semiautomated feature extraction algorithm is presented for the extraction and measurement of the hippocampus from volumetric magnetic resonance imaging (MRI) head scans. This algorithm makes use of elements of both deformable model and region growing techniques and allows incorporation of a priori operator knowledge of hippocampal location and shape.(More)
A novel method for the automated three-dimensional extraction and measurement of soft tissue lesions in CT imagery is presented. Extraction is carried out using a hybrid algorithm that incorporates elements from both competitive region growth and deformable template techniques. This algorithm is tested against manual tracing and shown to provide(More)
A method is presented for the calculation of perfusion parameters in dynamic contrast enhanced MRI. This method requires identification of enhancement curves for both tumor tissue and plasma. Inter-operator variability in the derived rate constant between plasma and extra-cellular extra-vascular space is assessed in both canine and human subjects using(More)
Three methods for extraction and quantitative measurement of features in CT and MR images are examined: hand tracing, semi-automated tracing using the livewire graph search algorithm, and extraction using a geometrically constrained region growth algorithm. Extracted structures are evaluated in terms of volume, cross-sectional area, and major axis in plane.(More)
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