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At least 559 records · Page 31Linked to original sources
PubMed1994

Quantification of area percentage of immunohistochemical staining by true color image analysis with application of fixed thresholds.

Most image analysis systems (IAS) use black-and-white cameras. However, true color IASs are considered to be useful for quantification of immunohistologically stained structures. Using a true color IAS, we evaluated two methods of segmentation for quantification of area percentage of staining: one using fixed, preset thresholds and one using thresholds interactively set per image. Furthermore, the effect of shading correction was evaluated, and measurements in both color and black-and-white mode were compared. The results of segmentation with fixed thresholds did not differ significantly from those of control percentages, established by interactive morphometry using a grid, which served as reference. Interactive segmentation was significantly different from the reference (t test, P = .0001). The effect of shading correction was negligible. Measurements with and without this procedure correlated highly (r = .99, P < .001). Comparison of the results obtained in color and black-and-white mode showed a significant difference in the latter from the reference (t test, P = .005). We conclude that it is possible to quantify, in a reliable way, area percentage of positive staining using a true color IAS with application of a segmentation method with fixed thresholds.

Breast Neoplasms↗
PubMed1984

Image analysis of FITC-immunofluorescence histochemistry in perivascular substance P-positive nerves.

The ability of image analysis to quantify nerves labelled by FITC-immunofluorescence histochemistry has been tested on whole-mount stretch preparations of perivascular substance P-positive nerves. It has been shown that image analysis can make consistent measurements of nerves demonstrated by immunohistochemistry despite the fading of FITC-fluorescence which occurs during storage and on exposure to ultraviolet light.

Animals↗
PubMed1998

Image analysis of proliferating cell nuclear antigen expression and immunohistochemical profiles in renal cell carcinoma associated with acquired cystic kidney disease: comparison with classic renal cell carcinoma.

Renal cell carcinoma (RCC) arising in acquired cystic kidney disease (ACKD) is considered to be a tumor of low malignant potential, compared with classic RCC. The aim of the present study was to identify any significant differences in the antigenic profiles or tumor cell proliferative activity of ACKD-associated RCC and classic RCC that might be responsible for differences in their biologic behavior. We studied the immunohistochemical profiles and proliferative activity of 12 classic RCCs and 5 ACKD-associated RCCs with markers of proximal tubules (Leu M1, alpha-1 antitrypsin, CAM 5.2), markers of distal tubules (Arachis hypogaea lectin, AE1/AE3, epithelial membrane antigen [EMAJ, CAM 5.2), vimentin, and proliferating cell nuclear antigen (PCNA). We performed proliferation analysis with the CAS 200 image analysis system. For each case, 8 to 20 fields of tumor tissue in the areas of maximal PCNA staining were quantitated, and the percentage of PCNA-positive nuclear area for each individual tumor was calculated. All of the five ACKD-associated RCCs expressed AE1/AE3, EMA, and CAM 5.2 in more than 50% of the tumor cells. Arachis hypogaea lectin was significantly expressed in three of the five ACKD-associated RCCs. Leu M1 and alpha-1 antitrypsin reacted with fewer than 10% of the tumor cells in all of the five ACKD-associated RCCs. In contrast, the 12 classic RCCs showed expression of CAM 5.2 in 11 cases, alpha-1 antitrypsin in 10 cases, Leu M1 in 9, EMA in 8, and AE1/AE3 in 3 cases in more than 50% of the tumor cells and a totally negative reaction with Arachis hypogaea lectin in 8 cases, EMA in 4, AE1/AE3 in 4, and vimentin in 5 cases. Although coexpression of proximal and distal tubule markers was seen in some cases of RCC in either category, there was uniform and strong staining for distal tubule markers in ACKD-associated RCC and for proximal tubule markers in classic RCC. The mean percentage of PCNA-positive nuclear area for the ACKD-associated RCCs (2.41%) was significantly (P < .05) less than that of the classic RCCs (21.42%). The differences in expression of proximal and distal tubule markers and proliferative activity might be responsible for the differences in the biologic behavior of ACKD-associated RCC and classic RCC.

Adult↗
PubMed2002

Comparison of semi-automated image analysis and manual methods for tissue quantification in pancreatic carcinoma.

Objective measurements of tissue area during histological examination of carcinoma can yield valuable prognostic information. However, such measurements are not made routinely because the current manual approach is time consuming and subject to large statistical sampling error. In this paper, a semi-automated image analysis method for measuring tissue area in histological samples is applied to the measurement of stromal tissue, cell cytoplasm and lumen in samples of pancreatic carcinoma and compared with the standard manual point counting method. Histological samples from 26 cases of pancreatic carcinoma were stained using the sirius red, light-green method. Images from each sample were captured using two magnifications. Image segmentation based on colour cluster analysis was used to subdivide each image into representative colours which were classified manually into one of three tissue components. Area measurements made using this technique were compared to corresponding manual measurements and used to establish the comparative accuracy of the semi-automated image analysis technique, with a quality assurance study to measure the repeatability of the new technique. For both magnifications and for each tissue component, the quality assurance study showed that the semi-automated image analysis algorithm had better repeatability than its manual equivalent. No significant bias was detected between the measurement techniques for any of the comparisons made using the 26 cases of pancreatic carcinoma. The ratio of manual to semi-automatic repeatability errors varied from 2.0 to 3.6. Point counting would need to be increased to be between 400 and 1400 points to achieve the same repeatability as for the semi-automated technique. The results demonstrate that semi-automated image analysis is suitable for measuring tissue fractions in histological samples prepared with coloured stains and is a practical alternative to manual point counting.

Algorithms↗
PubMed2004

Statistical image analysis of high-sensitivity neutron images obtained by cooled CCD systems.

Neutron sensitivity and noise characteristics of cooled CCD NR systems were investigated. Eighteen species of neutron sensitive scintillators were tested by the use of two types of cooled CCD devices. The statistical analysis of the S/N ratio of the neutron images showed that the ZnS+LiF type was the highest sensitivity scintillator. The generation rate of the CCD noises increased with increasing exposure time, temperature of the device and dose rate of the environmental radiation. The generation rate and the pulse height distribution of the noise were quite different between the two CCD devices. Thus, the origin of the noise is considered to be strongly related to the internal structure of the CCD devices.

Journal Article↗
PubMed1989

[Evaluation of the anti-ulcer drugs using image analysis technology: effect of aldioxa containing preparation on the experimental gastric ulcer in rats].

Direct measurements under a microscope have been employed to evaluate experimental gastric ulcers, but the following problems have been left unsettled: it takes too much time, and much experience is required to perform accurate, objective measurements. The present study demonstrates the usefulness of image analysis technology for evaluating anti-ulcer drugs. With this newly developed method, the region of gastric mucosal injury can be automatically and/or mechanically chosen on the basis of three different factors: intensity, hue and purity. Consequently, this method can be used to rapidly obtain analytical data such as the number, area and length of gastric ulcers. Effect of NNP, a preparation containing aldioxa, on three different types of experimental ulcer formation (stress-induced, ethanol-induced, and pylorus-ligation) was studied by image analysis technology. In all cases, NNP (2,562 mg/kg, p.o.) almost completely inhibited the formation of rat gastric ulcer. From the finding that image analysis technology is very useful for evaluating anti-ulcer drugs, we conclude that this method will help further the development of anti-ulcer drugs.

Allantoin↗
PubMed1985

An inexpensive microcomputer-based image-analysis system: novel applications to quantitative autoradiography.

We describe a relatively inexpensive, yet versatile and powerful microcomputer-based image-analysis system, and its applications to processing of deoxyglucose autoradiographic data. Images are acquired via a video camera mounted on a light microscope or a light box, and digitized in 40 ms to 512 X 512 picture elements with 8-bit resolution (256 gray levels). The bit-mapped image analysis hardware can provide up to 256 colors for pseudo-color coding, and virtually instantaneous readout of brightness values for densitometry. The system is controlled by an 8-bit S-100 bus microcomputer, providing flexibility and ease of expansion. In addition to pseudo-color coding and densitometry, we have developed programs for averaging of successive sections, image subtraction and quantitative reconstruction of different planes of section from serial autoradiograms.

Animals↗
PubMed1988

Microcomputer-based digital image analysis system for quantitative autoradiography.

A computerized image processing system utilizing an IBM-XT personal microcomputer with the capability of performing quantitative cerebral autoradiography is described. All of the system components are standard computer and optical hardware that can be easily assembled. The system has 512 horizontal by 512 vertical axis resolution with 8 bits per pixel (256 gray levels). Unlike other dedicated image processing systems, the IBM-XT permits the assembly of an efficient, low-cost image analysis system without sacrificing other capabilities of the IBM personal computer. The application of this system in both qualitative and quantitative autoradiography has been the principal factor in developing a new radiopharmaceutical to measure regional cerebral blood flow.

Animals↗
PubMed1984

Fully automated and fast image analysis of autoradiographs with a TAS-Leitz. Determination of size, Feulgen fluorescence and grain counts of individual nuclei and their evaluation by a simplified cluster analysis.

A fully automatic analysis system based on television image analysis was developed to measure simultaneously three parameters in individual nuclei of microscopic autoradiographs prepared from mouse jejunal crypt cell squashes and ascites tumor cell smears: size, Feulgen fluorescence and reflection from silver grains. A dark light camera with an image intensified silicon tube (RCA-ISIT), an automatic scanning stage and an autofocus device were fitted to a Leitz-TAS microscope. The camera permitted localization of Feulgen stained nuclei and measurement of area and light intensity by means of incident of light fluorescence in the red. After automatic changes of the Opak-illuminator silver grains were determined by means of polarized incident light reflected from the grains in the blue. A 25 X oil objective (aperture 0.75) yielded sufficient resolution for measurements. The nadir between the proportions of labeled and unlabeled nuclei was calculated from the data of one specimen on a PDP-computer using a new algorithm based on the minimal variance of the logarithm of reflected light per nucleus. Labeling indices determined by visual grain counting and by automatic analysis of the autoradiographs were well correlated (r = 0.87 to 0.92). Visual grain counts/nucleus and reflected light/nucleus correlated well when individual nuclei were compared (r = 0.92 to 0.97) or means of labeled nuclei of various specimens prepared during a 5 year period (r = 0.90 to 0.93). Quenching of nuclear Feulgen fluorescence was minimal. The optimal labeling range is 30-100 grain counts/nucleus. The time interval between measurements of two specimens was 25 min for a squash of approximately 350 crypt cells within a 3 mm X 3 mm field, and 20 min for a meandering scan with 1,000 ascites tumor cells.

Animals↗
PubMed2002

Image analysis of Transwell assays in the assessment of invasion by malignant cell lines.

This study aims to determine if layering of extracellular matrix (ECM) can achieve a physiological basement membrane thickness of 8 microm and to assess the use of paraffin wax-embedded Transwell plates coupled with digital image analysis as a means of determining invasion by malignant cell lines. Layers of Matrigel, a sarcoma-derived ECM was built to a concentration of 7.4 microg/mm2 in the upper chamber of a Transwell plate invasion assay. Two cell lines from extrahepatic bile duct adenocarcinoma were tested in serum-free growth medium. Conditioned medium was added to the lower chamber to act as a chemoattractant. Following attachment, cells were incubated for 48 h and the Matrigel-coated insert cut from its holder and fixed in 10% unbuffered formalin saline. Each insert was bisected and processed to paraffin wax. Serial levels were stained by haematoxylin and eosin. A Kontron image analysis system was used to measure the mean thickness of Matrigel for each cell line and the degree of invasion was assessed by measuring the depth to which cells had degraded the Matrigel. A mean thickness of 8 microm was achieved using 5.0 microg/mm2 for the OCUCh-LM1 cell line and 7.4 microg/mm2 for the SKChA-1 cell line. No significant difference was seen in the ability of either cell line to degrade Matrigel. Immunocytochemistry for laminin and cytokeratin helped to identify ECM components and cells, respectively. In conclusion, digital image analysis of paraffin wax-embedded inserts can be used to determine the invasive capacity of various cell lines; immunocytochemistry may help to identify ECM components and cells; and the assay used to assess different cell lines and their ability to degrade Matrigel.

Adenocarcinoma↗
PubMed1986

A microcomputer system for video image analysis and diagnostic microdensitometry.

A system for microdensitometry based on a microcomputer, video digitizer and solid-state camera has been developed. Image analysis and densitometry are achieved with convenient control over image editing and calibration. The linear photometric properties of the imaging device enable measurements of high accuracy. The system has proven to give rapid and repeatable performance for determining DNA content distribution from measurements of Feulgen-stained cell nuclei. The results show that a practical image analysis microdensitometer can be designed using a readily available microcomputer. The low cost and simple operation are of benefit for diagnostic applications in which flow cytometry is not possible, the time required for microscope photometry is too great or an automated image analyzer and support staff are not available.

Animals↗
PubMed1995

Nucleolar organizer regions and image analysis nuclear morphometry of small cell (nevoid) melanoma.

Small cell (nevoid) melanomas may provide difficulties in diagnosis as their constituent cell type resembles a benign nevoid melanocyte. In the present study, 10 small cell melanomas were analyzed for the silver staining of their nucleolar organizing regions (AgNORs), and their nuclear area and perimeter were measured by computerized digital image analysis and compared with 10 superficial spreading melanomas lacking small cell differentiation and 10 dermal nevi. The average number of AgNORs per nucleus was 5.83 (SD +/- 1.69) for small cell melanomas and was significantly different when compared with 8.49 (SD +/- 1.58) for superficial spreading melanomas (p < 0.05) and 2.71 (SD +/- 0.50) for dermal nevi (p < 0.05). Digital image analysis confirmed that the nuclear perimeter and nuclear area of cells in nevoid melanomas did not significantly differ from those of ordinary dermal nevi (p > 0.05), but both group were significantly different from superficial spreading melanomas lacking a small cell morphology (p < 0.05). Counting AgNOR numbers may be useful in evaluating small cell (nevoid) melanomas and provides a technique for differentiating their constituent cell from ordinary nevus cells. Nuclear morphometry determined by digital image analysis may help better define the nuclear size in small cell melanomas.

Adolescent↗
PubMed1993

Quantitative evaluation of mRNAs by in situ hybridization and image analysis: principles and applications.

We describe an image analysis (IA) program that has been developed for the quantitative evaluation of mRNA evidenced by in situ hybridization (ISH) with radiolabeled probes in cultured cells and tissue sections. ISH-IA allowed the detection and quantitative evaluation of mRNA expressed by heterogeneous in vitro cultured cells. This method, when combined with dot-blot analysis, allowed the evaluation of the approximate number of mRNA molecules expressed by single cells. IA permitted the evaluation of cultured cells' morphological parameters (such as cytoplasm and nucleus areas) modifications in relation to specific mRNAs expression, which can vary during cell cycle, development, aging, and in different pathologies and treatment with drugs. ISH-IA was applied for the evaluation of mRNA isoforms generated by alternative splicing in single cells. This methodology was also applied for the semiquantitative evaluation and comparison of mRNA levels expressed by different cell types in human normal and tumor tissue sections.

Alternative Splicing↗
PubMed1987

High resolution scanning of absorbing and fluorescent electrophoresis gels using video image analysis.

A low cost, microcomputer-controlled image analysis system is described which scans electrophoresis gels or photographic negatives with high resolution. Absorbing gels (e.g. with stained proteins) are analyzed using broadband or monochromatic visible light. The gel is scanned by a video camera with a macro objective; the gray level of each pixel is digitized sequentially and the values are stored in the computer memory. Repetitive scanning is used to average the absorption values before plotting on a digital plotter. Photographic negatives of gels and autoradiograms are scanned using the same technique. Fluorescent, non-absorbing gels (e.g. nucleic acids stained with ethidium bromide) are analyzed on a transilluminator with u.v. excitation radiation. The fluorescence intensity of each pixel is digitized and processed as described above.

Autoradiography↗
PubMed2003

A cross-platform public domain PC image-analysis program for the comet assay.

The single-cell gel electrophoresis, also known as the comet assay, has gained wide-spread popularity as a simple and reliable method to measure genotoxic and cytotoxic effects of physical and chemical agents as well as kinetics of DNA repair. Cells are generally stained with fluorescent dyes. The analysis of comets--damaged cells which form a typical comet-shaped pattern--is greatly facilitated by the use of a computer image-analysis program. Although several image-analysis programs are available commercially, they are expensive and their source codes are not provided. For Macintosh computers a cost-free public domain macro is available on the Internet. No ready for use, cost-free program exists for the PC platform. We have, therefore, developed such a public domain program under the GNU license for PC computers. The program is called CASP and can be run on a variety of hardware and software platforms. Its practical merit was tested on human lymphocytes exposed to gamma-rays and found to yield reproducible results. The binaries for Windows 95 and Linux, together with the source code can be obtained from: http://www.casp.of.pl.

Algorithms↗
PubMed2004

Computerized image analysis vs semiquantitative scoring in evaluation of kidney allograft fibrosis and prognosis.

BACKGROUND: Chronic morphological changes in the kidney allograft predict long-term graft function, but there are few studies comparing different methods in assessing chronic lesions. In the present study, we evaluated allograft cortical interstitial fibrosis, and compared semiquantitative assessment with computerized image analysis of Sirius red-stained collagen in prediction of graft prognosis. METHODS: Sections were obtained from a series of 1-year protocol living donor kidney graft biopsies (n = 33) and their corresponding baseline specimens (n = 32). At light microscopy, the biopsies were scored for interstitial fibrosis as a percentage of involved tubulointerstitium according to the Banff schema. Quantitation of cortical fractional interstitial fibrosis volume (Vint) was performed with computerized image analysis on coded sections stained with Sirius red. The results were correlated with kidney function at 8-10 years after transplantation, and with late graft loss. RESULTS: There was a significant correlation between the semiquantitative and quantitative methods for measuring cortical interstitial fibrosis in all the biopsies (n = 65, percentage area vs Vint: R = 0.439, P = 0.0003). The correlation further improved when analysing the baseline specimens separately (n = 32, R = 0.704, P<0.0001) and was still significant, but less precise for the 1-year biopsies (n = 33, R = 0.384, P = 0.0274). One-year semiquantitative fibrosis (percentage area) was correlated to serum creatinine at 8-10 years (P = 0.010) and to late graft loss (P = 0.0445). The 1-year Vint values for interstitial fibrosis showed a similar trend but did not reach statistical significance in prediction of long-term graft function. CONCLUSIONS: Image analysis quantitation of interstitial collagen with Sirius red corresponded well to light microscopic semiquantitative assessment of interstitial fibrosis. In prediction of long-term graft function, the semiquantitative method was superior, indicating that accumulation of matrix molecules other than fibrillary collagens, oedema and inflammation are also important in graft prognosis.

Adult↗
PubMed1999

Optic nerve morphology may reveal adverse events during prenatal and perinatal life--digital image analysis.

OBJECTIVE: To evaluate optic nerve morphology in children with various conditions caused by adverse events during prenatal and/or perinatal life and to investigate whether optic nerve morphology can reveal brain lesions associated with these conditions, as well as provide insight into the etiology and timing of the prenatal and perinatal damage. METHODS AND PATIENTS: A digital image analysis technique was used to analyze fundus photographs. One hundred healthy Swedish individuals of various ages from childhood to adolescence constituted a reference group. The following patient groups were chosen to represent various clinical conditions affecting the newborn or fetus at different stages of development: children born preterm (N = 39), children with fetal alcohol syndrome (FAS [N = 16]), children with periventricular leukomalacia (PVL [N = 17]), and children with septo-optic dysplasia (SOD [N = 6]). RESULTS: Preterm children without known brain lesions demonstrated normal optic disk morphology but abnormal retinal vascular pattern; children born preterm with an acquired brain lesion late in gestation (PVL) demonstrated normal disk size with enlarged cups in addition to the abnormal vascular pattern. Children with prenatal alcohol exposure (FAS) had a subnormal optic disk area with increased tortuosity of both arteries and veins, whereas children born at term with an early acquired brain lesion (SOD) had a markedly reduced optic disk area with isolated tortuosity of the retinal veins. CONCLUSIONS: Evaluation of optic nerve morphology, by digital image analysis, demonstrated that differences in ocular fundus morphology were correlated with differences in etiology and timing of the adverse event occurring in prenatal and perinatal life. In addition, digital image analysis may be a helpful tool for understanding variations in optic nerve and retinal vessel morphology and their relationship with central nervous pathology.

Adolescent↗