An approach to the use of infrared digitized thermal imaging in clinical diagnosis is described. It is based on the temporal analysis of hundreds of consecutive digitized thermal images (thermograms). Like any thermos...
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ISBN:
(纸本)0818620390
An approach to the use of infrared digitized thermal imaging in clinical diagnosis is described. It is based on the temporal analysis of hundreds of consecutive digitized thermal images (thermograms). Like any thermostated system local skin temperature oscillates as it is driven by systemic and local nervous factors. The oscillations, which may be of diagnostic value, can be derived only from dynamic studies. The average temperatures of small areas of the skin on the human back (12 to 25 cm2) were used to determine the primary regulatory frequencies using fast Fourier transformation analysis. Both asymptomatic subjects and people with back problems of neurological origin were studied. Preliminary findings show regulatory frequencies which may be associated with pathology.
Methods of reducing the amount of data required to determine a clinical impression of a patient's condition are presented. The visualization of cardiac magnetic resonance images with color encoded 2-D and 3-D func...
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ISBN:
(纸本)0818620390
Methods of reducing the amount of data required to determine a clinical impression of a patient's condition are presented. The visualization of cardiac magnetic resonance images with color encoded 2-D and 3-D functional images is discussed. Color functional images, calculated from quantitative analysis of the image sequences, are created to direct the physician to areas of abnormality. These images indicate regions of hyper- or hypokinesis, abnormal ejection fractions and wall thickening. By selection of a region of abnormality from the functional images the actual image data and quantitative measurements of that particular area can be observed. This approach, going from data compressed into visual representations toward the original scans, provides an efficient method for reviewing large data sets of information without obscuring the original data or inhibiting access to information.
The quality of different shading algorithms for use in tomographic volume visualization (z-buffer gradient, gray-level gradient, adaptive gray-level gradient, marching cubes, marching cubes segmentation with Phong int...
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ISBN:
(纸本)0818620390
The quality of different shading algorithms for use in tomographic volume visualization (z-buffer gradient, gray-level gradient, adaptive gray-level gradient, marching cubes, marching cubes segmentation with Phong interpolation, transparent gray-level gradient), using simulated and clinical data, is investigated. Error images are used to visualize deviations of the calculated surface normal vectors from the ideal values. For the assessment of transparent rendering, reflection maps are used. The best results are obtained with adaptive gray-level gradient shading and marching cubes segmentation with Phong interpolation. The first method is based on the voxel model and thus is especially suitable for interactive data exploration. The second creates a polygon structure, which may be manipulated with methods developed in computer graphics. Transparent gray-level gradient shading should only be used if no binary segmentation can be done.
Successful treatment planning in radiation therapy depends in part on understanding the spatial relationship between patient anatomy and the distribution of radiation dose. Several visualizations based on volume rende...
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ISBN:
(纸本)0818620390
Successful treatment planning in radiation therapy depends in part on understanding the spatial relationship between patient anatomy and the distribution of radiation dose. Several visualizations based on volume rendering that offer potential solutions to this problem are presented. The visualizations use region boundary surfaces to display anatomy, polygonal meshes to display treatment beams, and isovalue contour surfaces to display dose. To improve perception of spatial relationships, metallic shading, surface and solid texturing, synthetic fog, shadows, and other artistic devices are used. Also outlined is a method based on 3-D mip maps for efficiently generating perspective volume renderings and beam's-eye views.
The authors describe a PC AT-based workstation that allows stereotactic neurosurgery to be planned using stereoscopic digital subtraction angiography (DSA) projections in conjunction with computed tomography (CT) and/...
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ISBN:
(纸本)0818620390
The authors describe a PC AT-based workstation that allows stereotactic neurosurgery to be planned using stereoscopic digital subtraction angiography (DSA) projections in conjunction with computed tomography (CT) and/or magnetic resonance (MR) image data. Techniques for correlating the positions of targets and for performing measurements in images acquired from different modalities (i.e., CT, MR and DSA) are presented. The stereoscopic approach is discussed and compared with conventional methods of planning stereotactic neurosurgery. This method is found to be enlightening in terms of its ability to provide the observer with a 3-D appreciation of the imaged structure. The ability to perform quantitative measurements, as well as view projection image data in 3-D, is an attractive feature of the stereoscopic workstation and is considered crucial to planning many stereotactic procedures.
A totally automated rule-based expert system developed for interpreting three-dimensional myocardial perfusion distributions obtained from thallium-201 tomographic images is described. Over 200 heuristic rules have be...
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ISBN:
(纸本)0818620390
A totally automated rule-based expert system developed for interpreting three-dimensional myocardial perfusion distributions obtained from thallium-201 tomographic images is described. Over 200 heuristic rules have been generated for interpreting stress perfusion defects and their characteristics. Perfusion defects are identified in terms of pixels below gender-matched normal patient distributions. Perfusion defects which reversed with time are identified in terms of pixels above gender-matched normal patient distributions. The expert system automatically calculates certainty factors from each perfusion defect to provide the relative certainty associated with the location and shape of each myocardial perfusion defect, as well as with the presence, location, and character of each coronary lesion. Results from a test using a pilot group of 20 patients are given.
The author presents an overview of the state of the art in biomedicalvisualization and simulation and provides a brief tutorial on the various computer graphics modeling representations, with pointers toward more in-...
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The author presents an overview of the state of the art in biomedicalvisualization and simulation and provides a brief tutorial on the various computer graphics modeling representations, with pointers toward more in-depth information. A set of properties based on empirical knowledge of the properties of the structures and organisms concerned, yet sensitive to the current limitations of the ability of computers to model the physical world, is put forth. A brief discussion of many biological phenomena whose study would be well served by utilization of the graphics and stimulation techniques discussed is presented.< >
The use of images of a patient's internal anatomy as the basis for the design and optimization of radiation treatment plans, the precise identification of the target disease volume and normal surrounding organs, t...
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The use of images of a patient's internal anatomy as the basis for the design and optimization of radiation treatment plans, the precise identification of the target disease volume and normal surrounding organs, the importance of verifying the delivery of presented therapy, and the visualization and correlation of computer tomography and magnetic resonance imaging volumes to facilitate treatment are discussed.< >
A representation of image intensity structure, the multiscale orientation field (MOF), is described, and its application to biomedical image segmentation is discussed. The MOF is composed of orientation vectors at eve...
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A representation of image intensity structure, the multiscale orientation field (MOF), is described, and its application to biomedical image segmentation is discussed. The MOF is composed of orientation vectors at every pixel and at multiple scales. The vectors are computed from the outputs of an artificial visual system composed of spatial filters whose design is described. An abstract feature space for orientation measurement is defined, and a filter sensitivity function that yields a desirable mapping into the feature space is described.< >
The authors discuss the implementation of a method of image registration that uses the edges of common features and is suited to the coarse grain parallel model of communicating sequential processes. Results are given...
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The authors discuss the implementation of a method of image registration that uses the edges of common features and is suited to the coarse grain parallel model of communicating sequential processes. Results are given for performance of sections of the algorithms on a small network of transputers. Some of the factors which must be considered in using a parallel system are discussed.< >
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