David R. Bailes

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In many object recognition systems only geometric constraints on the boundaries of the objects are used. Many authors have shown the merit in determining the distinctiveness of boundary constraints, and using these to speed up and improve the robustness of object recognition algorithms. However, if the objects have variable shapes or the image is cluttered,(More)
A method of reducing respiratory artefact when using the spin warp technique of magnetic resonance imaging is described. A respiratory signal is used to determine the order in which the rows of the data matrix are measured. The aim is to make the respiratory signal at the time of each phase encoding gradient a slowly varying function of the time integral of(More)
A nuclear magnetic resonance (NMR) imaging system is described, and preliminary results from its clinical use are presented. The properties and detection of the magnetisation due to hydrogen protons are outlined, and a rotating frame is introduced to describe the motion of the magnetisation. Radiofrequency (RF) pulses are used to rotate the magnetisation,(More)
Eight normal volunteers and 32 patients with a variety of neurological disease were studied with a nuclear magnetic resonance (NMR) scanner using repeated free induction decay (RFID), inversion-recovery (IR) and spin-echo (SE) sequences. The results were compared with X-ray computed tomography (CT). RFID sequences which produce images that reflect changes(More)
A nuclear magnetic resonance (NMR) machine constructed by Thorn-EMI Ltd was used to produce tomographic images of the brain in eight volunteers and fourteen patients. The use of an inversion recovery technique designed to emphasise variations in the spin-lattice time constant (T1) resulted in remarkable differentiation between grey and white matter in all(More)
Enhancement of spin-lattice relaxation using oral ferric chloride and using inhaled oxygen is illustrated. A 0.06% solution of ferric chloride reduced the spin-lattice relaxation time in the fundus of the stomach from 730 ms to 285 ms. Ferric chloride may be useful as a bowel-labeling agent. In 5 volunteers inhalation of 100% oxygen decreased the mean(More)
The aim of this work is to find out whether the grey level symmetric axis transform (SAT) is a useful grey level shape description for finding the salient cavities in echocardiograms. The centres of the maximal discs of the grey level SAT are calculated using mathematical morphology as described by Peleg and Rosenfeld, and these centres are grouped to form(More)
The results of NMR examinations in 52 patients with histological or clinical diagnoses of cerebral tumor are reviewed. An increase in relaxation time was recognized in all tumors but problems were experienced in distinguishing the margin of tumors from surrounding edema. Mass effects were well demonstrated as a result of the high level of gray-white matter(More)
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