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Results for “Image analysis”

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PubMed1984

Keratoconus and normal cornea: a comparative study of the collagenous fibers of the corneal stroma by image analysis.

Using an automatic image analysis technique, we studied the characteristics of the collagenous fibers of the corneal stroma of keratoconus at different stages of development. The clear portions of keratoconus specimens were studied at three different levels: anterior, middle, and posterior. The parameters obtained were compared with those of a normal adult cornea with the purpose of determining which ultrastructural alterations were caused by the appearance and progression of keratoconus.

Adolescent↗

PubMedDate not supplied

The spinal cord development in guinea pig: a morphometric study on an image analysis system.

Using an image analysis system, the Authors carried out a morphometric study on guinea pig spinal cord in order to determine volumetric changes of white and gray matter during development. White and gray matter volumes were determined by measuring the area occupied by these matters in 10 micrograms sections of spinal cord in 1 day and 90 days old subjects. Several topographic correspondences in the localisation of the lowest and highest volumetric values were observed in the two groups of subjects. Such correspondences were more marked for white than gray matter. Moreover, during growth white matter volume showed an increase double that observed in gray matter.

Animals↗

PubMed1987

Quantitation of estrogen receptor content and Ki-67 staining in breast carcinoma by the microTICAS image analysis system.

The microTICAS image analysis system, originally designed for karyometry using Papanicolaou-stained or Feulgen-stained smears and tissue sections, has been adapted to assess tissue sections stained by immunohistochemical techniques. This system was used to quantitate growth fractions and the estrogen receptor (ER) content of breast carcinomas stained by immunoperoxidase techniques. The results were similar to those obtained with nonautomated methods of quantitating immunohistochemically stained tissue sections and, in the case of ER content, were similar to the results obtained with cytosol estrogen binding methods. The findings show that the microTICAS system provides an objective alternative to visual counting of labeled cells in tissue sections stained for growth fraction or for ER content by immunohistochemical methods.

Antibodies, Monoclonal↗

PubMed1991

Mapping of glial fibrillary acidic protein-immunoreactivity in the rat forebrain and mesencephalon by computerized image analysis.

Computer-assisted image analysis was used to map the regional distribution of glial fibrillary acidic protein-immunoreactive (GFAP-IR) astrocytes in the rat forebrain and mesencephalon. A complete survey of packing densities of GFAP-IR structures was performed. Computer maps revealed high values in the outer and inner layers of the cortex, some hippocampal and olfactory bulb layers, prepiriform cortex, dorsal part of the caudate-putamen, globus pallidus, lateral septum, reticular thalamic nucleus, lateral habenular nucleus, circumventricular organs, nuclei of the medial hypothalamus, substantia nigra, interpeduncular nucleus, and mamillary body. These correspond to regions of the embryonic pial and ventricular brain surfaces, which undergo developmental alterations including growth and various forms of internalization. From this we conclude that in the adult brain, astrocytes of high GFAP-IR are derivatives of surface-contact glia, whereas those located in areas having developed by the local thickening of the neural tube wall show reduced or no GFAP-IR.

Animals↗

PubMed2005

Quantification of vesicles in differentiating human SH-SY5Y neuroblastoma cells by automated image analysis.

A new automated image analysis method for quantification of fluorescent dots is presented. This method facilitates counting the number of fluorescent puncta in specific locations of individual cells and also enables estimation of the number of cells by detecting the labeled nuclei. The method is here used for counting the AM1-43 labeled fluorescent puncta in human SH-SY5Y neuroblastoma cells induced to differentiate with all-trans retinoic acid (RA), and further stimulated with high potassium (K+) containing solution. The automated quantification results correlate well with the results obtained manually through visual inspection. The manual method has the disadvantage of being slow, labor-intensive, and subjective, and the results may not be reproducible even in the intra-observer case. The automated method, however, has the advantage of allowing fast quantification with explicitly defined methods, with no user intervention. This ensures objectivity of the quantification. In addition to the number of fluorescent dots, further development of the method allows its use for quantification of several other parameters, such as intensity, size, and shape of the puncta, that are difficult to quantify manually.

Algorithms↗

PubMed1991

Morphonuclear relationship between prostatic intraepithelial neoplasia and cancers as assessed by digital cell image analysis.

Using digital cell image analysis performed on Feulgen-stained nuclei, the nuclear characteristics of prostatic neoplasia, ranging from benign (benign prostatic hyperplasia [BPH]), through dysplastic (prostatic intraepithelial neoplasia [PIN] 1-3), to carcinoma were studied. Four histopathologic groups were studied: group IA (18 samples) contained BPH, PIN 1, and PIN 2 lesions that were from 9 prostate samples free of cancer. Group IB (23 samples) was identical to group IA, contained also BPH, PIN 1, and PIN 2 lesions, but lesions that were from 7 prostate samples where malignant foci were detected elsewhere. Group II (11 samples) were PIN 3 specimens. Group III (24 samples) were carcinomas. Features of neoplastic nuclei were quantified objectively through morphometric (nuclear size), densitometric (nuclear DNA content), and textural (chromatin organization and heterogeneity) parameters. Cell kinetic parameter, i.e., cell proliferation index, was assessed from the densitometric measurement. The proliferation index was significantly higher in PIN 3 and cancers as compared to BPH, PIN 1, and PIN 2 tissues. Morphonuclear characteristics were also dramatically distinct among the four groups. Indeed, the nuclear size and the hyperchromatism of severe prostatic dysplasia were similar to those of carcinomas, these two lesion types showing mean parameter values that were higher as compared to BPH, PIN 1, and PIN 2 lesions. Finally, benign tissues related to mild or moderate dysplasia taken in histologic material in which cancer was present already share the morphonuclear characteristics of severe dysplasia, although they are nonproliferating.

Cell Nucleus↗

PubMed1995

Evaluation on blood platelets by the image analysis system VIDAS 2.5.

This paper introduces a program written on the image analysis system VIDAS 2.5. It enables the automatic quantification of high numbers of adhesion areas of vital human platelets, thus allowing statistical analysis. These adhesion areas were observed by reflection contrast microscopy (RCM), which generates images of an intense contrast and serves as a prerequisite for an evaluation by image analysis. However, RCM-photographs of the observed platelets have highly varying mean greyvalues and greyranges. These common problems for self-operating identification are excluded by two procedures within the program: 1. calibration of the scanning process for an optimal use of the available greyvalues provided by the negative, camera, and the image analysis system; and 2. relation of the threshold for discrimination of adhesion areas to the statistic parameters of the histogram within each individual digitized image. Images processed according to these prerequisites were transferred to the VIDAS implemented routines for identification and measurement of areas. Thus, image analysis combined with RCM offers a tool for basic and clinical platelet research, which is shown by an example of stimulation and inhibited stimulation of platelet activation.

Blood Platelets↗

PubMed1995

Fully automatic determination of soil bacterium numbers, cell volumes, and frequencies of dividing cells by confocal laser scanning microscopy and image analysis.

We describe a fully automatic image analysis system capable of measuring cell numbers, volumes, lengths, and widths of bacteria in soil smears. The system also determines the number of cells in agglomerates and thus provides the frequency of dividing cells (FDC). Images are acquired from a confocal laser scanning microscope. The grey images are smoothed by convolution and by morphological erosion and dilation to remove noise. The background is equalized by flooding holes in the image and is then subtracted by two top hat transforms. Finally, the grey image is sharpened by delineation, and all particles above a fixed threshold are detected. The number of cells in each detected particle is determined by counting the number of local grey-level maxima in the particle. Thus, up to 1,500 cells in 10 fields of view in a soil smear are analyzed in 30 min without human intervention. Automatic counts of cell numbers and FDC were similar to visual counts in field samples. In microcosms, automatic measurements showed significant increases in cell numbers, FDC, mean cell volume, and length-to-width ratio after amendment of the soil. Volumes of fluorescent microspheres were measured with good approximation, but the absolute values obtained were strongly affected by the settings of the detector sensitivity. Independent measurements of bacterial cell numbers and volumes by image analysis and of cell carbon by a total organic carbon analyzer yielded an average specific carbon content of 200 fg of C (mu)m(sup-3), which indicates that our volume estimates are reasonable.

Journal Article↗

PubMed1994

Reproducibility study of posterior subcapsular opacities on the NEI retroillumination image analysis system.

We developed a semi-automated retroillumination image analysis system which combines speed, ease of operation and interactive analysis. The system measures cataract area and integral of cataract density (ID). For system reproducibility evaluation, 20 eyes with posterior subcapsular opacities were captured twice by two photographers. Variability was estimated under a random effects analysis of variance model. Measurement errors for area and for ID were each small contributors to total variability (the sum of variability between study eyes plus measurement error), being 0.4% and 0.1% respectively. The largest contributor to area measurement error was image analysis variability (97%). For ID measurement error, the variability in images (44%) and in image analysis (46%) were major contributors. The reproducibility is comparable to previously described retroillumination analysis systems. This easy to use system may therefore be useful in clinical research studies including possible clinical trials of anti-cataract drugs.

Adolescent↗

PubMed1993

Phase image analysis of anomalous ventricular activation in pediatric patients with preexcitation syndromes or ventricular tachycardia.

This prospective study evaluated the accuracy of phase analysis of scintigraphic imaging in defining the site of earliest ventricular activation in pediatric patients with electrophysiologic disorders. Twenty patients (10.8 +/- 5.5 years) with preexcitation (n = 16) or ventricular tachycardia (VT) (n = 4) were independently evaluated by phase image analysis and endocardial catheter mapping. The earliest phase angle (contraction), which was common to three scintigraphic imaging planes during preexcited sinus rhythm or VT, was compared with the earliest retrograde atrial activation during reciprocating tachycardia or the origin of VT, as defined by catheter mapping. Phase analysis of earliest contraction was concordant with catheter mapping of electrical activation in all 13 free-wall accessory connections and in three of four patients with VT. Inconclusive definition of activation occurred only in paraseptal accessory connections or VT. In conclusion, phase analysis accurately defines anomalous ventricular activation that is due to free-wall accessory connections or VT. In patients with complex anatomy or small size, phase analysis allows noninvasive localization of the anatomic substrates of tachycardia.

Adolescent↗

PubMed2002

On the development of a novel image analysis technique to distinguish between flocs and filaments in activated sludge images.

The ratio of flocs to filaments in activated sludge wastewater treatment plants is of extreme importance for the overall performance of the plant. In order to control this ratio the individual concentrations of flocs and filaments need to be measurable. However, no sensors which can measure these concentrations are currently available. In this paper it is outlined how a distinction can be made between flocs and filaments by means of image analysis techniques. Combination of this information with the total biomass concentration results in the individual floc and filament concentrations. The distinction of objects of interest from the background is a crucial step in the image analysis procedure. An automatic thresholding algorithm is proposed which selects two thresholds in images with one fraction darker than the background and the other fraction brighter than the background. Once the objects are separated from the background, they are classified as either flocs or filaments by means of the reduced radius of gyration.

Algorithms↗

PubMed1994

Quantification of superantigen induced IFN-gamma production by computerised image analysis--inhibition of cytokine production and blast transformation by pooled human IgG.

A quantitative image analysis technique was developed to assess the cytokine content of immunocytochemically stained cytokine producing cells. Peripheral blood mononuclear cells were stimulated to induce cytokine production with the superantigen streptococcal pyrogenic exotoxin-A. We have developed a method based on indirect immunocytochemistry which identifies IFN-gamma producing cells by a characteristic morphology generated by the accumulation of IFN-gamma in the Golgi organelle. An image analysis technique permitted discrimination between these producer cells and IFN-gamma binding target cells, which showed a different appearance, with staining restricted to the cell surface membrane. A semi-automated routine programme allowed the signal from a video camera to be processed by computerised image analysis methodology. This enabled us to measure the number of cytokine producing cells, the cytokine staining intensity in individual cells and the cell size expressed in actual cell area. The incidence of IFN-gamma producing cells determined by image analysis measurement was compared to results obtained using manual microscopy. Cell size was assessed by the image analysis system as well as by flow cytometry. Administration of pooled human IgG for intravenous use (IVIg) to the superantigen stimulated cells significantly down-regulated IFN-gamma production, both in terms of the numbers of producer cells and in terms of cytokine staining intensity in individual cells. In addition blast transformation of cells was substantially reduced. These effects, mediated by IVIg, were also evident following delayed IVIg administration 24 h after the initial cell stimulation.

Adult↗

PubMed1998

Image analysis assessment of testicular touch preparation cytologies effectively quantifies human spermatogenesis.

PURPOSE: We have recently demonstrated that computer assisted image analysis of paraffin embedded testicular tissue based on deoxyribonucleic acid content and morphology characteristics is an effective method for the quantitative assessment of spermatogenesis. We assess the use of testicular touch preparation image analysis as a technique for quantification of spermatogenesis. MATERIALS AND METHODS: Air dried, touch imprints of testicular tissue from obstructed azoospermic and severely oligozoospermic patients were obtained at the time of biopsy. Image analysis using a filter based on deoxyribonucleic acid content and cellular morphological characteristics was performed on Feulgen stained touch preparation imprints as well as paraffin embedded sections. RESULTS: Image analysis of 52 testicular touch preparations from 48 azoospermic or severely oligozoospermic men revealed significant differences (p < 0.05) in the percentages of spermatid and spermatozoa, and 2N and 4N cells among seminiferous tubules exhibiting the 5 diagnostic categories of obstruction with normal spermatogenesis, maturation arrest at the spermatocyte stage, maturation arrest at spermatid stage, hypospermatogenesis and Sertoli cell only. Similar differences were observed in the image analysis data of the corresponding paraffin embedded testicular sections. CONCLUSIONS: Computer assisted image analysis of testicular touch preparation is an effective quantitative method of spermatogenesis evaluation.

Adult↗

PubMed1989

Assessment of hormone receptors in breast carcinoma by immunocytochemistry and image analysis. II. Estrogen receptors.

Frozen sections of 30 invasive breast carcinomas were stained for estrogen receptors (ERs) and the tumor cell proliferative rate by an immunoalkaline phosphatase technique. The stained sections were evaluated for ER by the microTICAS image analysis system. Seventeen tumors were ER positive and 13 were ER negative by image analysis. There was 93% concordance between the ER results obtained by image analysis and those obtained by biochemical methods. One case that was ER negative by image analysis was weakly positive by biochemical assay; a second case was ER positive by image analysis but ER negative by biochemical assay. Twelve of the 17 ER-positive tumors were diffusely positive while 5 displayed considerable intratumoral heterogeneity, with tumor cells exhibiting a broad range of intensity of receptor expression. In most cases, the image analysis ER status coincided with the progesterone receptor (PR) status, but in a large minority of cases (41%) the ER status and the PR status differed. Tumors with a high growth fraction (greater than 30%), as measured by Ki-67 immunostaining, were uniformly ER negative. The results of this investigation suggest that immunohistochemical staining of frozen sections for ER aided by automated image analysis (1) reliably detects the receptor in breast carcinoma, (2) allows for the assessment of heterogeneity within tumors and (3) may be used as part of a panel of antibodies to markers of potential prognostic importance in a single small tissue sample.

Breast Neoplasms↗

PubMed1989

[Objective estimation of the motility of deep frozen cattle sperm by videomicrography and computer image analysis].

It was examined whether computerized image analysis (system "Brunner") is suitable for the objective evaluation of the quality of deep-frozen bull sperm obtained from the routine of breeding stations. Egg yolk particles similar in size to sperm heads were classified as immotile sperm. Thus, motility was significantly underestimated with the degree of underestimation depending on the thawing solution employed. The use of two different thawing solutions, CUE and Citrat-Glucose, resulted in significantly different sperm motion characteristics immediately after thawing as well as at the end of a 2 hour incubation period at 37 degrees C. Deep-frozen semen samples from seven bulls were compared with respect to their swimming activities. The rank order of the bulls based on the values for motility and mean velocity measured two hours post-thaw corresponded with the rank order of Non-Return-Rates with respect to bulls from the same breeding station. It appears that the combination of videomicrography and computerized image analysis is well suited for the objective evaluation of frozen-thawed bull sperm if the extender is pretreated to exclude an underestimation of motility caused by egg yolk particles.

Animals↗

PubMed1994

Image analysis quantification of the Miles assay.

The Miles assay for vascular permeability has high intra- and interassay coefficients of variation (CVs). Quantification, usually by dye extraction and spectrophotometry, is time consuming. In this study, quantification by this means was compared with image analysis using the Olympus CUE-2 Image Analyzer (version 4). The test substance was recombinant human vascular permeability factor (rhVPF). The quantification process took approximately 10 min with image analysis. Formamide extraction and spectrophotometry required 1 hr of preparation, 4-6 days of incubation, and 1 hr for filtration and spectrophotometry. Between assay CVs ranged from 0 to 30% for spectrophotometry, but were all < 10% for image analysis. The sensitivity (2SD above the negative control mean) of the image analysis approach was 64 +/- 25 ng/mL, whereas for spectrophotometry it was 65 +/- 29 ng/mL. Interanimal CVs for rhVPF at 200 and 1000 ng/mL were 15% and 26% when assessed by spectrophotometry and 7% and 22%, respectively, by image analysis. The R2 value for the correlation of image analysis with spectrophotometry was 81.4%. Test substances injected close to the spine evoked a greater permeability response than those injected laterally: at 200 ng/mL p = 0.005, at 1000 ng/mL p = 0.1 (unpaired t tests).

Animals↗

PubMed1994

Computer image analysis in the diagnosis of melanoma.

BACKGROUND: It is often difficult to differentiate early melanoma from benign pigmented lesions of similar clinical appearance. OBJECTIVE: Our purpose was to develop a computer image analysis system that has the potential for use as an adjunct to the clinical distinction of melanoma from less serious pigmented lesions. METHODS: The system, consisting of a hand-held device incorporating a color video camera and color frame grabber mounted in a microcomputer, was used in a pigmented lesion clinic. Analysis software extracted features relevant to the size, color, shape, and boundary of each lesion, and these features were correlated with clinical and histologic characteristics on which standard diagnoses of skin tumors are based. For discriminant analysis based on image analysis measurements, equal prior probabilities were assigned to two specified diagnostic groups, namely melanoma and "other pigmented lesions," most of which were melanocytic nevi. RESULTS: In a 20-month period, video images of 164 unselected pigmented lesions for which complete diagnostic data were available were successfully captured using the camera. Sixteen of 18 melanomas, and 89% of pigmented lesions overall, were correctly classified by the image analysis system, compared with 83% based on clinical gradings of lesion characteristics. CONCLUSION: Computer image analysis has the potential to provide a valuable diagnostic aid that could enable clinicians to make highly sensitive and specific diagnoses of early, curable melanoma.

Adolescent↗

PubMed1989

Comparison of stains for image segmentation and measurement of nuclear parameters by computerised image analysis using IBAS 2000.

Nuclear measurements using image analysis largely depend upon the quality of the image presented for digitization. To investigate the effects of nuclear stains on image segmentation of nuclei, serial sections of kidney were stained by eleven different methods and presented to an IBAS 2000 interactive image analysis system (Kontron Bildanalyse) via a Zeiss IIIRS microscope at x 800 magnification and a Siemens K30 video camera. Digitised grey level images of each field were processed by an interactive technique and by an automatic segmentation procedure (thresholding). Nuclear areas were measured by each method and the results compared. We conclude that of the stains assessed the uncounterstained haematoxylins offer the best image segmentation for nuclear measurements. Thresholding techniques are suitable for performing measurements using these stains, particularly when additional interactive techniques are used to reject unwanted structures and to separate overlapping nuclei after segmentation. Comparable areas stained with five of the stains were studied to see if the staining techniques themselves affected nuclear area. Our results show that the use of different stains will substantially affect measurements of nuclear dimensions.

Cell Nucleus↗