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At least 1,297 records · Page 72Linked to original sources
PubMed2002

[Measurement of flow velocity in feeder vessels of choroidal neovascularization with a scanning laser ophthalmoscope and image analysis system].

PURPOSE: To measure flow velocities in feeder vessels of choroidal neovascularization(CNV) secondary to age-related macular degeneration(AMD). METHODS: We examined early images of indocyanine green(ICG) angiography in 29 eyes with CNV secondary to AMD, in which feeder vessels could be identified. ICG videoangiographic images recorded at 30 frames per second with a scanning laser ophthalmoscope were installed in a personal computer. With original software, optical density measurements made with an image analyzer were performed on ICG videoangiograms for determination of dye-dilution curves. The time(T50) from the beginning of a dye-dilution curve to the ascending parts of the curve at 50% of the peak intensity was calculated. Flow velocity in a feeder vessel was obtained by dividing the distance between two points by the circulation time between T50 s at the two points on the feeder vessel. RESULTS: The mean flow velocity in feeder vessels was 33.8 +/- 32.5 (mean +/- standard deviation) mm/sec. The mean velocity in the feeder vessels of large CNV with greatest linear diameter of 1 disc diameter(DD) or larger was 43.4 +/- 30.6 mm/sec; the mean velocity in the feeder vessels of small CNV with greatest linear diameter smaller than 1DD was 20.3 +/- 20.2 mm/sec. There was a significant difference between them. CONCLUSION: The flow velocity in feeder vessels of CNV could be measured with ICG angiography and a computer-based image analysis system. This system would be useful in evaluation of choroidal circulation.

Aged↗
PubMed1990

Digital image analysis of variations in the origin of the deep femoral artery in human foetuses.

Examination of vessels' radiograms with the use of microcomputer digital image analysis was adopted to the femoral artery in human foetuses. The system makes it possible to shorten the investigation time as compared with conventional methods and to obtain objective results. Investigations were performed on 100 human foetuses (72 males and 28 females) aged 4th to 8th month. The configuration in the radiograms of the deep femoral artery showed four main origination types.

Female↗
PubMedDate not supplied

[Assessment of angiogenesis expression and its relationship with prognosis of colorectal cancer by conventional and computer-assisted histopathological image analysis].

PURPOSE: To quantify the degree of angiogenesis by conventional method (microvessel density, MVD) and computerized method (endothelial area, EA), and to evaluate their relationships with the prognosis of patients operated on for colorectal adenocarcinoma. METHODS: Tumoral angiogenesis was studied by means of an immunohistochemical technique, using CD 34, on 126 patients; to quantify the angiogenesis, MVD (defined as number of microvessels per mm(2)) and EA measurement (defined as the area occupied by EA in the microscope field). A computerized method, IMAGELab software was utilized to quantify endothelial area. RESULTS: The mean number of microvessels was 128.6 MV/mm(2) (SD = 44.5) and the mean EA was 4.3% (SD = 2.1). The Pearson method demonstrated a low correlation coefficient between MVD and EA (r = 0.429). No relationship between MVD and EA was observed with regard to relapse-free interval and overall survival. CONCLUSION: The histological analysis of angiogenesis expression in patients with colorectal adenocarcinoma can be performed either by computer-assisted image analysis of endothelial area or by conventional microvessels counting. Both methods did not show any significant relationship between these angiogenesis parameters with relapse-free interval and overall survival.

Adenocarcinoma↗
PubMed1996

[Studies on Cnidium fruits by stereological method and computer image analysis].

The fruits, pollen grains, vascular bundles, stomata and endosperm cells of 4 Cnidium species were studied and determined by stereological method and computer image analysis technique. Statistical data were presented. In the volume of fruit and the area of vascular bundle, Cnidium dahuricum is the biggest, then C. salinum, C. japonicum and C. monnieri successively. In the volume of pollen grain,C. salinum is the biggest, followed by C. dahuricum, C. japonicum and C. monnieri in succession. In the volume of endosperm cell, C. dahuricum is also the biggest, and then C. japonicum, C. salinum and C. monnieri in order.

Fruit↗
PubMed2000

A novel approach based on computerized image analysis for traditional Chinese medical diagnosis of the tongue.

This research is aimed at building a computerized tongue examination system (CTES) based on computerized image analysis for the purpose of quantizing the tongue properties in traditional Chinese medical diagnosis. The chromatic algorithm is developed to identify the colors of the tongue and the thickness of its coating. The textural algorithm is used to detect the grimy coating. CTES is shown to be significantly consistent within itself with P > 0.05 using the Hotelling multivariate statistical test. The overall rate of correctness for CTES to identify the colors of tongue, verifying the thickness of its coating and detecting of any grimy coating exceeds 86%. Therefore, the CTES is helpful to provide the physicians a systematic and objective diagnostic standard for the tongue diagnosis in the clinical practice and research.

Algorithms↗
PubMed2004

Image analysis of the shape of granulated powder grains.

This study presents and evaluates two new form factors for the characterization of pharmaceutical microparticles using image analysis techniques. The first factor, denoted Vr, is mean percentage variation in radial chord length (for a large number of radial chords drawn at small angular intervals) with respect to mean radial chord length. The second factor, denoted Vp, is percentage deviation of measured perimeter from the perimeter of a circle with radius equal to the mean radial chord length of the particle. Considering both ideal shapes and real pharmaceutical particle populations, these factors are compared with other form factors widely used in pharmaceutical technology. Our results indicate that Vr and Vp allow effective assessment of whether the particles of a given population show pharmaceutically significant deviations from sphericity. The two factors additionally facilitate identification of the basic shapes of particle outlines (notably ellipsoid, rectangular, and irregular). These factors may thus be of value for the characterization and monitoring of pharmaceutical pelleting processes.

Image Enhancement↗
PubMed1996

[Functional mapping of the motor and primary sensorial cortex using magnetic resonance techniques. II. Image analysis techniques].

Functional Magnetic Resonance Imaging (fMRI) techniques to investigate brain function are now available on clinical MR systems. However, the software packages provided with the MR equipment to analyze the functional images are often inadequate. In the present study, two registration algorithms for correcting motion artifacts and three procedures of statistical analysis (t-test, correlation analysis, Kolmogorov-Smirnov test) were compared using programs implemented on a graphic workstation. For both registration algorithms, transformation parameters for in plane translations and rotation of images were significantly affected by the task, being higher during sequential finger movements than during the control (visual imagery) condition. Regions of interest were identified on the anatomical images and their boundaries automatically projected on functional images. The number of significantly activated pixels in the pre- and postcentral areas was not significantly different after the registration with the two procedures. The percentage of pixels of the pre- and postcentral areas whose signal intensity was significantly different between the two tasks decreased with respect to the adopted threshold of significance as a power function. For an area identified outside the brain, the same relation was linear: no activated pixel was found for p < 0.001. The application of the t-test or of the correlation analysis yielded similar results. The analysis of the profile of mean normalized signal intensity showed higher increases in signal intensities during the motor task in the precentral gyrus than in the postcentral gyrus. This appears to be due to a greater number of activated pixels during motor performance. The application of registration procedures, the identification of the regions of interest on the basis of the anatomical images and appropriate statistical analyses allow a more detailed characterization of task-related activation.

Adult↗
PubMed1996

Structure of recombinant rat UBF by electron image analysis and homology modelling.

We have studied the structure of recombinant rat UBF (rrUBF), an RNA polymerase I transcription factor, by electron microscopy and image analysis of single particles contrasted with methylamine tungstate. Recombinant rat UBF appeared to be a flat, U-shaped protein with a central region of low density. In the dominant projections, 2-fold mirror symmetry was seen, consistent with the dimerization properties of this molecule, and of dimensions in agreement with the length of DNA that rat UBF protects in footprinting studies. Electron microscopy of various rrUBF-DNA complexes confirmed that our recombinant protein was fully able to bind the 45S rDNA promoter, and that it caused substantial bends in the DNA. Upon extended incubation in a droplet covered by a lipid monolayer at the liquid-air interface, rrUBF formed long filamentous arrays with a railway track appearance. This structure was interpreted to consist of overlapping rrUBF dimers 3.5 nm apart, which value would represent the thickness of the protein. Our results show rrUBF to interact with and bend the promoter DNA into a roughly 10 nm diameter superhelix. Based on all these electron microscopical results, an atomic structure was predicted by homology modelling of the HMG fingers, and connected by energy minimized intervening segments.

Animals↗
PubMedDate not supplied

Paradoxic uptake of Gd-EOB-DTPA by hepatocellular carcinoma in mice: quantitative image analysis.

To determine whether paradoxic uptake of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) occurs only with highly differentiated hepatocellular carcinomas, quantitative image analysis was performed in 37 mice with 133 hepatocellular carcinomas. The results of lesion/ liver signal intensity measurement and relative enhancement calculation indicate that paradoxic positive enhancement occurs independently of cellular differentiation.

Animals↗
PubMed1996

DNA-ploidy studies on cytological preparations from breast cancers by image analysis: comparison with Feulgen staining performed in destained Papanicolaou slides.

Image cytometric analysis of DNA ploidy status of 40 fresh primary breast carcinomas was performed in a comparative study on cytologic preparations stained directly by the Feulgen method and smears from the same tumors Feulgen-stained after Papanicolaou staining. There was a 0.82 overall concordance in diploid and aneuploid tumor classification and a good correlation (r = 0.736, P < 0.001) between the DNA indices determined by the two methods. Discordances are probably due to tumor heterogeneity. This study demonstrates that image cytometric DNA analysis on previously routine-stained cytologic preparations is feasible and reliable for pretreatment DNA analysis and suggests potential applications in retrospective studies with cytologic material from archives.

Adult↗
PubMed2004

A comparison of Profile, Hero 642, and K3 instrumentation systems in teeth using digital imaging analysis.

OBJECTIVE: To evaluate the changes in cross-sectional area morphology of curved canals after instrumentation with Profile((R)), Hero 642((R)), and K3((R)) using digital imaging analysis. Study design Thirty mesial mandibular curved canals were used (25-40 degrees ). The molars were embedded in resin and the roots were sectioned transversely at three levels: apical, middle, and coronal. The canals were randomly distributed into 3 groups for instrumentation using Profile.04 and.06, Hero 642, and K3. The pre- and postinstrumentation sections were digitized and areas corresponding to the canals were measured with image-processing software. RESULTS: Hero eliminated significantly more dentine than K3 and Profile in all 3 sections (P <.01, ANOVA test), with no differences observed between the latter 2 systems (P >.05, Student-Newman-Keuls test). All 3 systems yielded a rounded canal morphology in the coronal, middle, and apical thirds. CONCLUSION: Hero rotary instruments produced more changes in cross-sectional area of the root canal.

Analysis of Variance↗
PubMed1989

Computer-assisted densitometric image analysis (CADIA) for the assessment of alveolar bone density changes in furcations.

The purpose of this study was to test the applicability of computer-assisted densitometric image analysis (CADIA) for the quantitative assessment of alveolar bone density changes in furcations of multirooted teeth. In 21 patients, standardized radiographs were obtained immediately after and at 1, 6 and 12 months after periodontal flap procedures. Digitized images were obtained by means of a video-camera combined with an image processor that was linked to a computer. Quantitative information regarding density changes within windows covering furcation areas was obtained after superimposition and grey-level correction of images to be compared. 1 month after flap reflection, significantly more density loss was obtained in test furcations exposed to periodontal surgery, compared to the density changes in control furcation exposed to scaling and root planing. At 12 months, however, significantly greater increase in density was measured in test furcations compared to the 1-month results. The radiographic data were compared to the clinical parameters. In test furcations, there was a negative correlation of r = -0.52 between the GI and the loss in density at 1 month, and a negative correlation of r = -0.61 between the loss in density at 6 months and the probing attachment level at 12 months. These results indicate that CADIA may give valuable additional diagnostic information regarding alveolar bone density changes in furcations in studies on periodontal therapy.

Alveolar Process↗
PubMed1979

Computer image analysis of kidney histopathological sections.

Human renal histological sections have been photographed on a black and white transparency and digitized. The digitizing camera, an image dissector, converts a 2 cm2 picture into 400 x 400 numbers each representing the grey level value of sampled point. The grey levels are represented in the computer by number ranging between 0-255. In this scale 'O' stands for black and 255, for white. The program provides 2 grey level thresholds, which outline a window through which the picture is scanned. Only structures, whose grey level value lies in the window range, are taken into consideration. The thresholds are set during digitization from the console switches. Image analysis is performed on-line in real time.

Color↗
PubMed1997

Image analysis of protein profiles from paired microvillous and basal syncytiotrophoblast plasma membranes from term human placenta and characterization of IgG binding to membrane vesicles.

Image analysis of SDS-PAGE profiles of highly purified, paired maternal-facing (microvillous; MVM) and fetal-facing (basal; BM) plasmalemma membrane vesicles from six term human placentae showed that, while individual MVM or BM profiles were extremely reproducible, the two membrane populations were substantially different--although all of the seven major bands of molecular mass, 98.4, 79.4, 71.1, 45.1, 40.9, 39.5 and 34.5 kDa found in MVM were present, albeit in differing amounts, in BM. BM were characterized by the presence of five low molecular weight bands which were not present in MVM. Despite this consistency of the membrane preparations, binding of 125I-IgG or its fragments showed marked variability in both MVM and BM. At pH 7.4, both MVM and BM bound similar amounts of 125I-IgG with Kd values of 5.2 +/- 1.9 x 10(-6) M (s.e., n = 8) and 2.9 +/- 0.4 x 10(-6) M respectively, (P > 0.05). There were 1.2-1.6 x 10(15) binding sites/mg protein. Affinity constants for Fc fragment binding to MVM and BM were similar to those for IgG, although the Bmax value for BM Fc binding was greatly reduced compared to that for IgG (P > 0.001). Fab binding to MVM and BM was also saturable but substantially lower than that of Fc, whereas binding of F(ab')2 was low and linear. Both MVM and BM bound marginally more IgG at pH 6.0 than at pH 7.4. These data provide further evidence for receptor-mediated transcytosis of maternal IgG across the placenta and confirm that the placental IgG transporter differs from classical Fc gamma receptors.

Binding Sites, Antibody↗
PubMedDate not supplied

Fractal-assisted EUS image-analysis in the evaluation of variceal eradication after elastic band ligation.

BACKGROUND/AIMS: Endoscopic ultrasonography (EUS) is a strongly operator-dependent method. Mathematical algorithms in image-analysis are likely to enhance diagnostic accuracy. Incomplete eradication of esophageal varices can be demonstrated with EUS. The presence of paraesophageal varices, visible only with EUS, has been recently identified as a predictor of recurrence. The object of this study was to evaluate the usefulness of fractal-geometry-algorithms for the interpretation of EUS images and their impact on treatment decisions. METHODOLOGY: EUS was performed in 5 consecutive patients in order to detect the presence of paraesophageal varices after complete eradication of esophageal varices with elastic banding. Static images were analyzed and the fractal dimension was calculated. Follow-up ranged from 8-12 months. RESULTS: Fractal dimension was related to a) the presence and size of paraesophageal varices b) Child-Pugh Score c) rebleeding rate. Patients with a fractal dimension > 1.5 rebled. CONCLUSIONS: The use of mathematical algorithms derived from fractal geometry enhances interpretation in endosonographic imaging, increases the diagnostic yield and may prove helpful in making individual-tailored treatment decisions.

Adult↗
PubMed1997

Bone histomorphometry using interactive image analysis. A methodological study with application on the human temporomandibular joint.

The aim was to develop a reproducible method for bone histomorphometry with the aid of a computerized image analysis program, and to examine the variation when assessing the total and the trabecular bone volume. Histologic sections of 18 temporomandibular joint autopsy specimens were read interactively using a cursor. The two parameters total bone volume and trabecular bone volume, of the condyle and the temporal component respectively, were estimated 2 x by 1 observer using 3 different threshold settings: an automatic, a semi-automatic and a manual technique. The threshold was based on the gray-scale distribution of the image. 2 observers read the same sections with the aid of the semi-automatic technique. The intra-observer variation expressed as coefficient of variation ranged between 1.9% and 7.1% for the different parameters, when the automatic threshold setting technique was employed, and between 2.8% and 8.7% with the semi-automatic technique. The manual technique resulted in a high intra-observer variation with a coefficient of variation between 5.2% and 19.9%. There was a systematic difference between the estimates of the 2 observers. In general, intra- and inter-observer variation was higher in the temporal component than in the condyle. The inter-section variation was moderate, the coefficient of variation ranging from 3.8% to 11.1%. The automatic and semi-automatic techniques resulted in comparable intra-observer variation, with a lower bias in the estimates of the semi-automatic technique. By letting one observer apply the semi-automatic technique, it was possible to achieve fast and reproducible analysis of the total and trabecular bone volume.

Aged↗
PubMed1995

Estimation of motility of subgingival microflora using high speed shutter camera and image analysis system.

This paper reports on the development of a motility measuring system for human subgingival microflora using a high speed shutter camera and an image analysis system. The paper first presents the method for estimating the motility of subgingival microflora by the total number of pixels and then describes the evaluation of the total number of pixels as an indicator of bacterial motility. Our results with this system demonstrate that the motility of subgingival microflora can be expressed as the total number of pixels.

Bacterial Physiological Phenomena↗
PubMedDate not supplied

Quantification of masseter muscle deformation during palpation using MRI and image-analysis procedure.

PURPOSE: The aim of this study was to quantify masseter muscle deformation during palpation and to discuss the clinical significance of muscle palpation using magnetic resonance imaging (MRI) and the image-analysis procedure. MATERIALS AND METHODS: Subjects were 10 male volunteers with a mean age of 26.8 years. MRIs were taken under two muscle conditions: compressed and noncompressed (control). By superimposing a compressed image on a noncompressed image, muscle deformation (the cross-sectional area, length of the surrounding area, thickness, circular convolution, compressed point, and anterior and posterior extension) was measured. RESULTS: The cross-sectional area of the masseter muscle was diminished by 14%, circular convolution of the muscle was reduced by 31%, the length of the surrounding area was enlarged by 11%, and the thickness of the muscle was reduced by 6.7 mm because of compressing. Thus, the masseter muscle was compressed. An uneven stretch of the muscle caused by compression was observed at the same time. The anterior portion of the masseter muscles extended on average 10%, with great individual differences. On the other hand, posterior extension (3%) and its individual differences were small. CONCLUSION: The method used made it possible to quantify masseter muscle deformation. By compressing, the masseter muscles were deformed especially in the anterior direction but with great individual differences.

Adult↗