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Accuracy of helical computed tomographic angiography for the diagnosis of colonic angiodysplasia

GASTROENTEROLOGY 2000年第2期119卷 293-299页

作者： Junquera, F Quiroga, S Saperas, E Pérez-Lafuente, M Videla, S Alvarez-Castells, A Miró, JRA Malagelada, JR Autonomous Univ Barcelona Digest Syst Res Unit Hosp Gen Vall dHebron E-08035 Barcelona Spain Autonomous Univ Barcelona Dept Radiol Hosp Gen Vall dHebron E-08035 Barcelona Spain

Background & Aims: The diagnosis of colonic angiodysplasia is often challenging and relies on endoscopy or catheter angiography. We investigated whether computed tomographic angiography (CTA) contributes to the diagnosis of colonic angiodysplasia. methods: Twenty-eight patients with suspected bleeding from colonic angiodysplasia were prospectively evaluated. Gastrointestinal bleeding was investigated by colonoscopy plus visceral angiography and by CTA. The level of agreement between CTA and the former procedures was determined. Results: CTA images of diagnostic quality were obtained in 26 patients. Eighteen patients were diagnosed with colonic angiodysplasia by colonoscopy plus visceral angiography, and 14 by CTA (kappa = 0.68;P < 0.001). Sensitivity, specificity, and positive predictive values of CTA for detection of colonic angiodysplasia were 70%, 100%, and 100%, respectively. CTA signs including accumulation of vessels in the colonic wall, early filling vein, and supplying enlarged artery were present in 55%, 50%, and 22% of cases, respectively. None of these signs were present in the 8 patients with obscure gastrointestinal bleeding and negative diagnostic investigation of the digestive tract. Conclusions: CTA is a sensitive, specific, well-tolerated, and minimally invasive tool for the diagnosis of colonic angiodysplasia.

关键词： Aged Aged, 80 and over Angiodysplasia/radiography Angiography/methods Angiography/standards Colon/blood supply Colonic Diseases/radiography Female Gastrointestinal Hemorrhage/radiography Humans image processing, computer-assisted/methods image processing, computer-assisted/standards Male Middle Aged Prospective Studies Reproducibility of Results Tomography, X-Ray Computed/standards

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image processing techniques applied to excitation waves in the chicken retina

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methods-A COMPANION TO methods IN ENZYMOLOGY 2000年第4期21卷 317-323页

作者： Dahlem, MA Müller, SC Univ Magdeburg Inst Phys Expt Biophys Abt D-39016 Magdeburg Germany

image processing techniques are described in detail that are used to gain information about the dynamics of wave propagation in excitable media. We focus on a phenomenon called spreading depression (SD) observed in the chicken retina, but the techniques described here concern a large variety of excitable systems. Despite the impressive progress both in SD research of the past 50 years and, during nearly the same period, in the theory of self-organization of wave patterns, there is still little mutual overlap. However, the increasing demands for understanding complex systems, like neuronal tissue, require such theoretical concepts. Arguments are given why the chicken retina is a nearly perfect experimental system for assessing and further developing these concepts. (C) 2000 Academic Press.

关键词： Animals Central Nervous System/physiology Chickens image processing, computer-assisted/methods Microscopy, Video/instrumentation Microscopy, Video/methods Retina/physiology

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2-D and 3-D reconstruction for tracheal stenosis

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ANAESTHESIA 2000年第5期55卷 513-514页

作者： Rajesh, A Aslam, M Jeyapalan, K Glenfield Gen Hosp Leicester LE3 9QP Leics England

Reports on two-dimensional and three-dimensional reconstruction technique for tracheal stenosis. Causes of tracheal stenosis; Treatment of the disease; Success rate of therapeutic procedures for tracheal stenosis.

关键词： Adult Humans image processing, computer-assisted/methods Male Tomography, X-Ray Computed/methods Tracheal Stenosis/radiography

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Tomographic 3D reconstruction of quick-frozen, Ca²⁺-activated contracting insect flight muscle

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CELL 1999年第4期99卷 421-431页

作者： Taylor, KA Schmitz, H Reedy, MC Goldman, YE Franzini-Armstrong, C Sasaki, H Tregear, RT Poole, K Lucaveche, C Edwards, RJ Chen, LF Winkler, H Reedy, MK Florida State Univ Inst Mol Biophys Tallahassee FL 32306 USA Univ Penn Penn Muscle Inst Philadelphia PA 19104 USA MRC Mol Biol Lab Cambridge CB2 2QH England Duke Univ Med Ctr Dept Cell Biol Durham NC 27710 USA Max Planck Inst Med Forsch Biophys Abt D-69120 Heidelberg Germany

Motor actions of myosin were directly visualized by electron tomography of insect flight muscle quick-frozen during contraction. In 3D images, active crossbridges are usually single myosin heads, bound preferentially to actin target zones sited midway between troponins. Active attached bridges (similar to 30% of all heads) depart markedly in axial and azimuthal angles from Rayment's rigor acto-S1 model, one-third requiring motor domain (MD) tilting on actin, and two-thirds keeping rigor contact with actin while the light chain domain (LCD) tilts axially from similar to 105 degrees to similar to 70 degrees. The results suggest the MD tilts and slews on actin from weak to strong binding, followed by swinging of the LCD through an similar to 35 degrees axial angle, giving an similar to 13 nm interaction distance and an similar to 4-6 nm working stroke.

关键词： Actins/metabolism Animals Calcium Flight, Animal Flight, Animal Freezing Hemiptera/physiology image processing, computer-assisted/methods Microscopy, Electron/methods Models, Biological Muscle Contraction/physiology Muscle Fibers, Skeletal/metabolism Muscle Fibers, Skeletal/physiology Muscle Fibers, Skeletal/ultrastructure Myosin Light Chains/metabolism Time Factors Tomography/methods Troponin/metabolism

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Digital image processing for rapid analysis of differentially expressed transcripts on high-density cDNA arrays

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BIOTECHNIQUES 1999年第6期26卷 1174-+页

作者： Adryan, B Carlguth, V Decker, HJ Univ Mainz Med Clin 3 Dept Hematol Oncol Lab Tumorgenet & Mol Cytogenet D-55131 Mainz Germany

Usage of filter arrays is becoming increasingly attractive for many research laboratories involved indetermination of gene-expression profiles. However analysis of numerous spots, representing genes or partial gene sequences (ESTs), is still tedious work involving the ordered analysis of vast amounts of numerical tabular data. We present a vapid and efficient method for the visual identification of differentially expressed targets on high-density cDNA filter arrays using standard laboratory equipment and standard software, which is available for free. The method we introduce provides an inexpensive alternative, and no changes in the experimental set up are required. Our results were verified by densitometric analyses performed with an established system.

关键词： Autoradiography Autoradiography Cloning, Molecular/methods Color Densitometry/methods DNA, Complementary/analysis Gene Expression image processing, computer-assisted/methods Software Transcription, Genetic

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Imaging cortical dynamics at high spatial and temporal resolution with novel blue voltage-sensitive dyes

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NEURON 1999年第4期24卷 791-802页

作者： Shoham, D Glaser, DE Arieli, A Kenet, T Wijnbergen, C Toledo, Y Hildesheim, R Grinvald, A Weizmann Inst Sci Dept Neurobiol IL-76100 Rehovot Israel

Conventional imaging techniques have provided high-resolution imaging either in the spatial domain or in the temporal domain. Optical imaging utilizing voltage-sensitive dyes has long had the unrealized potential to achieve high resolution in both domains simultaneously, providing subcolumnar spatial detail with millisecond precision. Here, we present a series of developments in voltage-sensitive dyes and instrumentation that make functional imaging of cortical dynamics practical, in both anesthetized and awake behaving preparations, greatly facilitating exploration of the cortex. We illustrate this advance by analyzing the millisecond-by-millisecond emergence of orientation maps in cat visual cortex.

关键词： Animals Brain Mapping Brain Mapping Cats Cerebral Cortex/anatomy & histology Cerebral Cortex/physiology Coloring Agents/diagnostic use Electrophysiology Haplorhini Heart Rate/physiology image processing, computer-assisted/methods Orientation/physiology Photic Stimulation Rats

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Spatial extent of pigment epithelial detachments in age-related macular degeneration

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OPHTHALMOLOGY 1999年第9期106卷 1830-1840页

作者： Kunze, C Elsner, AE Beausencourt, E Moraes, L Hartnett, ME Trempe, CL Schepens Eye Res Inst Boston MA 02114 USA Schepens Retina Assoc Boston MA USA Harvard Univ Sch Med Boston MA USA Univ Klin Augenheilkunde & Optometrie Innsbruck Austria Augenklin Univ Regensburg Germany Univ Estadual Campinas Campinas Brazil

Objective: To quantify the spatial extent of pigment epithelial detachment (PED) associated with age-related macular degeneration (AMD) using a rapid, noninvasive method. Design: Prospective, cross-sectional study. Participants: The authors tested 32 eyes of 21 patients (13 women and 8 men) with AMD 56 to 91 years of age (mean = 72.8 years). The authors retested seven eyes of six patients. Intervention: Three-dimensional imaging and quantification of FED were performed in each subject using confocal infrared imaging (790 nm) with a Topographic Scanning System (TopSS), The data consisted of a series of 32 images within a 3-mm-depth range requiring 0.9 second. Three-dimensional calculations were made from the series. Main Outcome Measure: Height, diameter, area, volume, and slope of each FED were obtained with two calculation methods. The Ellipse Method used a graphics tool to draw elliptical borders circumscribing the region of interest in the image. The software automatically calculated the values for all parameters for the region inside the ellipse, with the retinal reference plane adjusted to match the height of the surrounding retina. The User-Defined Region Method differed in that the region of interest was drawn manually. Results: PEDs were easily detected in all patients using the TopSS. Maximum height of all PEDs above the reference plane ranged from 0.204 to 1.818 mm (mean = 0.57 mm). The diameter was 0.501 to 5.151 mm (mean = 2.711 mm), area was 0.179 to 20.402 mm(2) (mean = 6.585 mm2), and volume was 0.012 to 13.981 mm(3) (mean = 2.173 mm(3)). Intraobserver variability was low, with correlations between first and second measurements for the first visit ranging from r = 0.906 to 0.997 for slope and diameter, respectively. Conclusions: Three-dimensional analysis with the TopSS provides objective outcome measures not obtainable with typical clinical methods such as fundus photography and angiography. Height and volume are crucial in determining whether neovas

关键词： Aged Aged, 80 and over Cross-Sectional Studies Diagnostic Techniques, Ophthalmological Female Fluorescein Angiography Fundus Oculi Humans image processing, computer-assisted/methods Macular Degeneration/complications Male Middle Aged Pigment Epithelium of Eye/pathology Prospective Studies Retinal Detachment/diagnosis Retinal Detachment/etiology Tomography/methods

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methods for evaluation of retinal microvascular abnormalities associated with hypertension/sclerosis in the atherosclerosis risk in communities study

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OPHTHALMOLOGY 1999年第12期106卷 2269-2280页

作者： Hubbard, LD Brothers, RJ King, WN Clegg, LX Klein, R Cooper, LS Sharrett, AR Davis, MD Cai, JW Univ Wisconsin Dept Ophthalmol & Visual Sci ARIC Retinal Reading Ctr Madison WI 53705 USA NCI NIH Bethesda MD 20892 USA NHLBI ARIC Project Off NIH Bethesda MD 20892 USA Univ N Carolina Dept Biostat ARIC Coordinating Ctr Chapel Hill NC USA

Objective: To develop protocols to photograph and evaluate retinal vascular abnormalities in the Atherosclerosis Risk in Communities (ARIC) Study;to test reproducibility of the grading system;and to explore the relationship of these microvascular changes with blood pressure. Design: Population-based, cross-sectional study. Participants: Among 4 examination centers, 11,114 participants (48-73 years of age) at their third triennial examination, after excluding persons with diabetes from this analysis. methods: One eye of each participant was photographed by technicians with nonmydriatic fundus cameras. Reading center graders evaluated focal arteriolar narrowing, arteriovenous (AV) nicking, and retinopathy by examining slides on a light box and measured diameters of all vessels in a zone surrounding the optic disc on enhanced digitized images. To gauge generalized narrowing, vessel diameters were combined into central arteriolar and venular equivalents with formulas adjusting for branching, and the ratio of equivalents (AAI ratio) was calculated. Main Outcome Measures Retinal vascular abnormalities, mean arteriolar blood pressure (MABP). Results: Among 11,114 participants, photographs were obtained of 99%, with quality sufficient to perform retinal evaluations in 81%. In the 9040 subjects with usable photographs, A/V ratio (lower Values indicate generalized arteriolar narrowing) ranged from 0.57 to 1.22 (median = 0.84, interquartile range = 0,10), focal arteriolar narrowing was found in 7%, AV nicking in 6%, and retinopathy in 4%. Because of attrition of subjects and limitation of methods, prevalence of abnormality was likely underestimated. Controlling for gender, race, age, and smoking status, these retinal changes were associated with higher brood pressure. For every 10-mmHg increase in MABP, A/V ratio decreased by 0.02 unit (P < 0.0001), focal arteriolar narrowing had an odds ratio (OR) of 2.00 (95% confidence interval [CI] = 1.87-2.14), AV nicking had an OR of 1.2

关键词： Aged Blood Pressure Capillaries/pathology Coronary Artery Disease/complications Coronary Artery Disease/epidemiology Cross-Sectional Studies Diagnostic Techniques, Ophthalmological Female Fundus Oculi Humans Hypertension/complications image processing, computer-assisted/methods Male Middle Aged Photography/methods Reproducibility of Results Retinal Diseases/classification Retinal Diseases/diagnosis Retinal Diseases/etiology Retinal Vessels/pathology Risk Factors Sclerosis/complications United States/epidemiology

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computer-vision-enabled augmented reality fundus biomicroscopy

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OPHTHALMOLOGY 1999年第10期106卷 1935-1941页

作者： Berger, JW Shin, DS Univ Penn Scheie Eye Inst Comp Vis Lab Philadelphia PA 19104 USA Univ Penn Scheie Eye Inst Dept Ophthalmol Philadelphia PA 19104 USA

Purpose: To guide treatment for macular diseases and to facilitate real-time image measurement and comparison, investigations were initiated to permit overlay of previously stored photographic and angiographic images directly onto the real-time slit-lamp biomicroscopic fundus image. Design: Experimental study in model eyes, and preliminary observations in human subjects. methods: A modified, binocular video slit lamp interfaced to a personal computer and framegrabber allows for image acquisition and rendering of stored images overlaid onto the real-time slit-lamp biomicroscopic fundus image. Development proceeds with rendering on a computer monitor, while construction is completed on a miniature display interfaced directly with one of the slit-lamp oculars. Registration and tracking are performed with in-house-developed software. Main Outcome Measures: Tracking speed and accuracy, ergonomic acceptability. Results: computer-vision algorithms permit robust montaging, tracking, registration, and rendering of previously stored photographic and angiographic images onto the real-time slit-lamp fundus biomicroscopic image. In model eyes and in preliminary studies in a human eye, optimized registration permits near-video-rate image overlay with updates at 3 to 10 Hz and misregistration errors on the order of 1 to 5 pixels. Conclusions: A prototype for ophthalmic augmented reality (image overlay) is presented. The current hardware/software implementation allows for robust performance.

关键词： Algorithms Choroidal Neovascularization/pathology Fluorescein Angiography Fundus Oculi Humans image processing, computer-assisted/instrumentation image processing, computer-assisted/methods Macular Degeneration/pathology Microscopy Models, Anatomic

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Cup-to-disc ratio: Ophthalmoscopy versus automated measurement in a general population - The Rotterdam Study

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OPHTHALMOLOGY 1999年第8期106卷 1597-1601页

作者： Wolfs, RCW Ramrattan, RS Hofman, A de Jong, PTVM Netherlands Ophthalm Res Inst NL-1100 AC Amsterdam Netherlands Erasmus Univ Dept Ophthalmol Rotterdam Netherlands Erasmus Univ Dept Epidemiol & Biostat NL-3000 DR Rotterdam Netherlands Univ Amsterdam Acad Med Ctr Dept Ophthalmol NL-1105 AZ Amsterdam Netherlands

Objective: To determine the correlations between ophthalmoscopic estimations and the measurements with a semiautomated image-analysis device of the vertical cup-to-disc ratio (VCDR) in the human optic disc. Designs Population-based, cross-sectional study. Participants: All subjects 55 years of age and older from the population-based sample of 6777 ophthalmologically examined subjects from The Rotterdam Study of whom gradable optic disc transparencies of at least 1 eye and ophthalmoscopic data of the same eye were available. Main Outcome Measures: Ophthalmoscopic assessment of the VCDR and semiautomated measurement of the VCDR. methods: Indirect and direct ophthalmoscopy were performed in mydriasis to assess the VCDR, Optic disc transparencies made with a simultaneous stereoscopic telecentric fundus camera were analyzed with a semiautomated measurement system (Topcon imagenet). Results: In 5143 subjects, the mean ophthalmoscopic VCDR was 0.30 (standard error [SE], 0.0021;range, 0.00, 1.00) compared with a semiautomatically measured VCDR of 0.49 (SE, 0.0019;range, 0.04, 0.86;difference, 0.19;P < 0.0001). The overall correlation between both methods was moderate (correlation coefficient, 0.61;SE, 0.11) and lower in small optic discs. Semiautomated optic disc measurements correctly identified 76% of the glaucoma cases las defined using visual field data and ophthalmoscopic data about the optic disc). Conclusion: Semiautomated measurements of the VCDR are larger than the ophthalmoscopic VCDR estimate with a moderate correlation. The interobserver variability using imagenet was smaller compared with the ophthalmoscopic assessments, and imagenet was better standardized, which is important for epidemiologic surveys and follow-up studies.

关键词： Aged Aged, 80 and over Cohort Studies Cross-Sectional Studies Female Glaucoma, Open-Angle/diagnosis Humans image processing, computer-assisted/methods Male Middle Aged Netherlands Observer Variation Ophthalmoscopy/methods Optic Disk/pathology Photography Reproducibility of Results

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