Edward A. Ashton

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A n e w sub-pixel target detection algorithm is developed that integrates a linear mixing model (LMM) with the p o w e f i l "RX" anomaly detector of Reed and Y u (1990). RX i s applied to mixing model errors instead of to measured radiances, because they are more nearly multivariate Gaussian. The integrated method consistently outperforms spectral anomaly(More)
To obtain a three-dimensional reconstruction of the hippocampus from a volumetric MRI head study, it is necessary to separate that structure not only from the surrounding white matter, but also from contiguous areas of gray matter--the amygdala and cerebral cortex. At present it is necessary for a physician to manually segment the hippocampus on each slice(More)
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)
The QIBA initiative seeks to advance quantitative imaging and the use of imaging biomarkers in clinical trials and clinical practice by: 1) collaborating to identify needs and solutions to develop and test consistent, reliable, valid, and achievable quantitative imaging biomarker results across imaging platforms, clinical sites, and time, and 2)(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)
Rapid, accurate and reproducible delineation and measurement of arbitrary anatomical structures in medical images is a widely held goal, with important applications in both clinical diagnostics and, perhaps more significantly, pharmaceutical trial evaluation. This process requires the ability first to localize a structure within the body, and then to find a(More)