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Characterization of changes in placental ultrasonic images using digital techniques
ABSTRACTS, ULTRASONIC IMAGING AND TISSUE CBARACTERIZATION SYMPOSIUM
using peak detect, minimum detect, integrate and average reconstruction algorithms. Peak detect shows good grey scale display of parenchymal echoes and also gives highlights from specular echoes. This highlight effect can be a disadvantage as beamwidth and multiple reflection or reverberration artifacts tend to write from only one direction and are highAveraged reconstruction reduces lighted by the peak detect reconstruction. It tends highlights from a single direction and thereby reduces artifact. to give a more even texture to parenchymal echoes and the resolution is However, the highlights improved due to reduction of beamwidth artifact. due to specular echoes from vessels, etc., are reduced. With some echo pre-processing some of the highlight effect of peak detect can be restored without losing the other advantages. The use of minimum detect has been suggested to emphasize omni-directional reflectors compared with specular ones. Progress results indicate that in certain areas, features and structures are recoanized in the minimum detect reconstruction which are not visible in the peak of averaged reconstructions. Examples of the various reconstructions and their different properties will be presented with clinical material from the abdomen, fetus, placenta, and breast. CHARACTERIZATION OF CHANGES IN PLACENTAL ULTRASONIC IMAGES USING DIGITAL TECHNIQUES. D. C. Almond', B. Ginzz, and W. I. J. Prycel. IDepartment of Medical Physics and Clinical Engineering, Northern General Hospital, ?-Department of Obstetrics and Gynecology, Northern General Hospital, Sheffield, u. f-z. A computer based signal processing system has been built for digital In vivo tissue data are collected analysis of clinical ultrasound data. via purpose-built electronic processing equipment and storage of the digitized video waveform is software controlled. Features seen in B-scan images have been quantitated by operating a variety of statistical and texture analysis techniques on the digitized A-scan information. A brief description of data collection system and method will be presented. A series of antenatal patients at different stages of pregnancy were first studied and parameters derived from the ultrasonic investigation were assessed for correlation with fetal age and visual description of the B-scan image. Those parameters relating to features in the ultrasonic image are now being used to monitor placental aging during gestation. Some preliminary results will be presented. IMAGE QUANTITATION OF ULTRASONIC SECTOR B-SCANS. D. Nicholas, D. 0. Cosgrove, P. Garbutt, D. K. Nassiri, and S. Pussell, Institute of Cancer Research/ Royal Marsden Hospital, Sutton, Surrey, U.K. A system is described for the retrospective analysis of ultrasonic information displayed in conventional sector B-scan images. Recent diagnostic machines utilize analog or digital scan-converters as temporary storage devices for the ultrasonic images. This enables us to generate specific readout rasters and select portions of image for digitization and storage on a magnetic cartridge device. Subsequent transfer to a DEC PDPB/e mini-computer allows the images to be analyzed by simple pattern recognition and image enhancement techniques. The former have been applied to disorders where a noticeable change occurs in the spatial distribution of the parenchymal echoes, while the latter aid the differentiation between focal abnormalities and small blood vessels or ducts. Our present computational set up involves applications of both techniques for a variety of clinical abnormalities. Our novel off-line data collection system allows us to digitize sector B-scan imaaes to a-bit resolution (usina an analoa scan-converter) with a pixel sepa;ation of 0.5 mm. Our digitized matrices can vary in size from 64 x 64 pixel images to 256 x 256; the latter effectively encompass the whole B-scan image. The magnetic cartridge storage device is file structured and is capable of accepting up to 400, 64 x 64 matrices on a single tape. The versatility and ease of use of this system means it has high clinical acceptance. This paper reports on our off-line instrumentation and will present results of the computational techniques applied to images depicting a
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using peak detect, minimum detect, integrate and average reconstruction algorithms. Peak detect shows good grey scale display of parenchymal echoes and also gives highlights from specular echoes. This highlight effect can be a disadvantage as beamwidth and multiple reflection or reverberration artifacts tend to write from only one direction and are highAveraged reconstruction reduces lighted by the peak detect reconstruction. It tends highlights from a single direction and thereby reduces artifact. to give a more even texture to parenchymal echoes and the resolution is However, the highlights improved due to reduction of beamwidth artifact. due to specular echoes from vessels, etc., are reduced. With some echo pre-processing some of the highlight effect of peak detect can be restored without losing the other advantages. The use of minimum detect has been suggested to emphasize omni-directional reflectors compared with specular ones. Progress results indicate that in certain areas, features and structures are recoanized in the minimum detect reconstruction which are not visible in the peak of averaged reconstructions. Examples of the various reconstructions and their different properties will be presented with clinical material from the abdomen, fetus, placenta, and breast. CHARACTERIZATION OF CHANGES IN PLACENTAL ULTRASONIC IMAGES USING DIGITAL TECHNIQUES. D. C. Almond', B. Ginzz, and W. I. J. Prycel. IDepartment of Medical Physics and Clinical Engineering, Northern General Hospital, ?-Department of Obstetrics and Gynecology, Northern General Hospital, Sheffield, u. f-z. A computer based signal processing system has been built for digital In vivo tissue data are collected analysis of clinical ultrasound data. via purpose-built electronic processing equipment and storage of the digitized video waveform is software controlled. Features seen in B-scan images have been quantitated by operating a variety of statistical and texture analysis techniques on the digitized A-scan information. A brief description of data collection system and method will be presented. A series of antenatal patients at different stages of pregnancy were first studied and parameters derived from the ultrasonic investigation were assessed for correlation with fetal age and visual description of the B-scan image. Those parameters relating to features in the ultrasonic image are now being used to monitor placental aging during gestation. Some preliminary results will be presented. IMAGE QUANTITATION OF ULTRASONIC SECTOR B-SCANS. D. Nicholas, D. 0. Cosgrove, P. Garbutt, D. K. Nassiri, and S. Pussell, Institute of Cancer Research/ Royal Marsden Hospital, Sutton, Surrey, U.K. A system is described for the retrospective analysis of ultrasonic information displayed in conventional sector B-scan images. Recent diagnostic machines utilize analog or digital scan-converters as temporary storage devices for the ultrasonic images. This enables us to generate specific readout rasters and select portions of image for digitization and storage on a magnetic cartridge device. Subsequent transfer to a DEC PDPB/e mini-computer allows the images to be analyzed by simple pattern recognition and image enhancement techniques. The former have been applied to disorders where a noticeable change occurs in the spatial distribution of the parenchymal echoes, while the latter aid the differentiation between focal abnormalities and small blood vessels or ducts. Our present computational set up involves applications of both techniques for a variety of clinical abnormalities. Our novel off-line data collection system allows us to digitize sector B-scan imaaes to a-bit resolution (usina an analoa scan-converter) with a pixel sepa;ation of 0.5 mm. Our digitized matrices can vary in size from 64 x 64 pixel images to 256 x 256; the latter effectively encompass the whole B-scan image. The magnetic cartridge storage device is file structured and is capable of accepting up to 400, 64 x 64 matrices on a single tape. The versatility and ease of use of this system means it has high clinical acceptance. This paper reports on our off-line instrumentation and will present results of the computational techniques applied to images depicting a
176