Showing papers by "Georgia College & State University published in 1990"
TL;DR: It was found that, when present in PMMA, several compounds of either bismuth or uranium or 35% of an organo-zirconium compound impart radiopacity equivalent to that of aluminum, indicating that a high level of biocompatibility can be expected.
49 citations
Journal Article•
TL;DR: Results indicated that youthful mentally retarded and nonretarded prison inmates did not adjust to incarceration in a similar manner and behavior in prison was significantly different across certain measures by group.
Abstract: Adaptation of young inmates with and without mental retardation to prison regime was examined The mean number of disciplinary reports received across five categories of infractions were compared Differences were evaluated with one-way analysis of variance and follow-up tests Results indicated that (a) youthful mentally retarded and nonretarded prison inmates did not adjust to incarceration in a similar manner and (b) behavior in prison was significantly different across certain measures by group Inmates with mental retardation demonstrated poor overall adjustment in prison
17 citations
15 citations
TL;DR: The volume of the encephalic ventricles was determined from computerized tomographic (CT) and magnetic resonance imaging (MRI) scans of seven subjects without apparent pathology and three subjects with enlarged venticles using a larger number of subjects using an MRI volumetric data base.
Abstract: The volume of the encephalic ventricles was determined from computerized tomographic (CT) and magnetic resonance imaging (MRI) scans of seven subjects without apparent pathology and three subjects with enlarged ventricles Since there are many conditions in which the encephalic ventricles become enlarged such as Alzheimer's disease and hydrocephalus, accurate measurement of these structures provides (1) a valuable and safe means of aiding in the diagnosis of such conditions and (2) important follow-up information on affected patients This paper presents the data obtained from the second phase of a three phase study The first phase demonstrated the possibility of measuring fluid filled spaces by MRI in three phantom preparations (small, medium, and large “ventricles”) The results were compared with those obtained from the computerized tomography (CT) scans of the same preparations This phase of the study compares the volumes obtained from CT scans with those obtained from MRI scans of the same individuals The volumetric calculations were done with the aid of a Calcomp 9000 digital analyser programmed to compensate for the scale factor and slice thickness of the images The results obtained from the MRI scans correlated closely with those obtained from the CT scans of the same subjects The third and final phase of the project is the development of an MRI volumetric data base for the encephalic ventricles using a larger number of subjects
10 citations
TL;DR: The phantom study showed that the results obtaining from the MRI scans were better than those obtained from the CT scans in measuring the volume of water-filled cavities (ventricles) in gelatin phantoms, and the average percent difference between volumes obtained by an imaging procedure compared to the actual volume as determined by water displacement was 15.8%.
Abstract: The volume of the encephalic ventricles was determined from magnetic resonance imaging (MRI) scans Since there are many conditions in which the encephalic ventricles become enlarged such as Alzheimer's disease and hydrocephalus, accurate measurement of the ventricles provides a valuable and safe means of aiding the diagnosis of such conditions and also provides important follow-up information in affected patients The objective was pursued in a three phase study This paper presents the data obtained from the first phase This first phase demonstrated the possibility of measuring fluid filled spaces by MRI in three phantom preparations (small, medium, and large “ventricles”) The results were compared with those obtained from computerized tomography (CT) scans of the same preparations These volumetric calculations were done with the aid of a Calcomp 9,000 digital analyzer programmed to compensate for the scale factor and slice thickness of the images The phantom study showed that the results obtained from the MRI scans were better than those obtained from the CT scans in measuring the volume of water-filled cavities (ventricles) in gelatin phantoms The average percent difference between volumes obtained by an imaging procedure compared to the actual volume as determined by water displacement was 158% for CT scanning and a more impressive 83% for MRI
10 citations
TL;DR: The MRI scans of 38 subjects found to have no apparent pathology were evaluated and the ventricular volume in each case was calculated by using methods previously developed in the laboratory, compared with published volumes determined from studies that used either ventricular casts or computerized tomographic scans.
Abstract: Accurate volume determination of the encephalic ventricles is of importance in several clinical conditions, including Alzheimer's presenile dementia, schizophrenia, and benign intracranial hypertension. Previous studies have investigated the accuracy with which magnetic resonance imaging (MRI) can be used in clinical practice to evaluate the encephalic ventricles. However, adequate evaluation of pathological conditions depends on a sufficient amount of morphometric data from normal subjects. To begin establishing this data base for “normal” subjects, we evaluated the MRI scans of 38 subjects found to have no apparent pathology and calculated the ventricular volume in each case by using methods previously developed in our laboratory. The results were then compared with published volumes determined from studies that used either ventricular casts or computerized tomographic scans. The average total ventricular volume for all 38 subjects was 17.4 cm3, while that for males was 16.3 cm3 and that for females was 18.0 cm3. A small but significant correlation was found between age of subject and ventricular volume, with ventricular size increasing with age.
10 citations
03 Apr 1990
TL;DR: Results show that algorithm 3 generates better interpolated objects than the segmented volumes arising from standard grayscale-based interpolation techniques in cases where the objects to interpolate are thin tube-like structures, such as the coronary arteries.
Abstract: The problem of interpolating a high-resolution binary-valued 3-D image given a lower-resolution grayscale 3-D image and a corresponding segmented 3-D image is addressed. Three algorithms for this problem are described. Algorithms 1 and 2 perform shape- and located-based binary interpolation. Algorithm 3, which subsumes algorithms 1 and 2, incorporates grayscale information as well as object shape and slice-to-slice object spatial relationships. Results show that algorithm 3 generates better interpolated objects than the segmented volumes arising from standard grayscale-based interpolation techniques. Algorithm 2, which subsumes algorithm 1, uses only the known presegmented volume to interpolate a new binary-valued volume. the methods show particular merit in cases where the objects to interpolate are thin tube-like structures, such as the coronary arteries. >
9 citations
TL;DR: From a social science perspective, however, the study suggesting that socioeconomic status accounts for more than one third of the mortality differential between blacks and whites is disappointing.
Abstract: To the Editor.— As a social scientist, I rejoiced when I read the study by Otten et al, 1 which suggested that socioeconomic status accounts for more than one third of the mortality differential between blacks and whites. From a social science perspective, however, their
1 citations