Biomedical subjects
K I Pearce
Publications and source records attributed to K I Pearce.
The latency period of carcinoma-in-situ of the cervix.
The age-specific incidence figures for gonorrhea and cervical carcinoma-in-situ in Alberta, Canada, have been correlated. The findings suggest that when reliable population-based data are available, changes in incidence and age distribution for gonorrhea can be regarded as predictive for comparable changes in incidence and age distribution for carcinoma-in-situ of the cervix with a delay in presentation of approximately five years. The latency period of carcinoma-in-situ of the cervix does not seem to vary considerably among different age groups. The results of the present study support the theory that a sexually transmitted infectious agent could be an etiologic factor in cervical cancer. Because gonorrhea rates in younger women indicate that they are engaging in earlier sexual activity with more partners, regular cervical screening should be encouraged to prevent a potential major increase of invasive cervical cancer.
Police negotiations. A new role for the community psychiatrist.
This paper reviews the type of individual who might be involved in a hostage situation and police negotations. It singles out those clinical characteristics which are important in determining the management of the negotiations, and in doing so adds a plea for psychiatrists to become involved in an advisory role. By pointing out the need for psychiatrists and police to review some of the problems and determine a common approach before the situations arise, an additional characteristic is added to the role description of the community psychiatrist.
A comparison of care given by family practitioners and psychiatrists in a teaching hospital psychiatric unit.
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Towards a completely computerized record system.
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The relationship of psychiatric psychosomatic and organic illness in a general practice.
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Toward quantitative characterization of the caudate nucleus through CT image enhancement.
Dilated lateral cerebral ventricles have been reported in association with psychiatric disorders. The dilatation is likely secondary to changes in anatomically related centers in the brain. Our attention is focused on the caudate nucleus and the need to develop quantitative characterization of it in psychiatric research. A computer method is described for accurately detecting the edges of the caudate nuclei in CT scans. The method consists of a two-dimensional filtering step to reduce image noise, followed by gradient computation for edge enhancement, and then an edge detection step to identify and record the caudate nuclei cross sections. Results from both head scans and synthetic images indicate that the method is successful even for low-contrast edges where the standard deviation of image noise approaches the difference in mean HU across the edge. The availability of an automated method of delineating the caudate nucleus permits the cross-sectional area and shape to be determined, the density to be estimated, and, from a set of closely spaced slices, volume information to be obtained.
Linearity and contrast scale control in computed tomography.
The aim of this paper is to present linearity studies and quality control charts for changes in the computed tomography (CT) number of water and contrast scales for two CT scanners over one year. Linear regression relates the attenuation coefficient to CT number. The CT number for water and the contrast scale values as obtained from the fit are: CT1 = (-0.13 +/- 1.3) Hounsfield units (HU), CT2 = (-1.8 +/- 1.6) HU and contrast scale (CS)1 = (1.80 +/- 0.03) 10(-4) cm-1 HU-1, CS2 = (1.82 +/- 0.02) 10(-4) cm-1 HU-1 for Picker International scanner models 600SE and 1200SX, respectively. Direct measurements of CT numbers are compared with fitted results, providing a necessary preliminary steps in the development of objective CT interpretation.