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PubMed1988

The correction of ultrasonic image analysis features for their depth dependence.

Ultrasound has long been used for clinical imaging purposes and for estimating the properties of tissues. More recently image analysis techniques have been used for quantifying the image's texture. These techniques have had limited success due primarily to the dependence of the texture measures on the depth of the sample volume. A simple algorithm has been developed for deriving a correction for this effect; its efficacy is demonstrated on placental data.

Algorithms↗
PubMed2003

Computerized image analysis of Sirius Red-stained renal allograft biopsies as a surrogate marker to predict long-term allograft function.

Chronic allograft nephropathy (CAN) is a major problem in posttransplant management. The lack of a reliable and early surrogate marker of CAN has hampered patient care and research. In this study, the Cortical Fractional Interstitial Fibrosis Volume (V(IntFib)), quantitated with computerized image analysis of Sirius Red-stained protocol biopsies, was examined as a potential surrogate for time to graft failure (TTGF) in 68 renal allograft recipients. At 6 mo posttransplant, V(IntFib) was highly correlated with TTGF (r = 0.64, P < 0.001). Both the Banff Chronic Sum and the Acute Sum Scores were also correlated with TTGF, but less strongly (r = 0.28, P < 0.02; r = 0.35, P < 0.003, respectively). As V(IntFib) was not correlated with the Banff Chronic Score, a multivariate model was created that incorporated V(IntFib) and both Acute and Chronic Banff pathology. This model was highly correlated with TTGF (r = 0.7, P < 0.0001). These findings suggest that V(IntFib) determined by computerized image analysis of Sirius Red-stained protocol biopsies at 6 mo posttransplant, with or without incorporation of Banff acute and chronic scoring, may provide an early surrogate for time to graft failure in renal allograft recipients.

Adult↗
PubMed2006

Epifluorescence microscopy and image analysis of high-level polycyclic aromatic hydrocarbon contamination in soils.

Interactions between polycyclic aromatic hydrocarbons (PAHs) and soil are an important determinant of their chemical availability and transport. Laboratory examination of microscale PAH-soil interaction is limited by the availability of methods for particle-scale observation. Inverted epifluorescence microscopy, combined with digital photography and computer image analysis, was evaluated for specificity and linearity using dissolved PAHs. A pyrene filter (excitation wavelength, 360-400 nm; emission wavelength, 450-520 nm) gave nonspecific PAH fluorescence, and bias for fluoranthene, benzo[b]fluoranthene, benzo[g,h,i]perylene, and benz[a]anthracene was quantified in comparison to that for pyrene. Concentrations ranging from 1 to 10 mM for anthracene, fluoranthene, and pyrene and from 1 to 50 mM for naphthalene produced a linear response with low interpixel variability. Liquid-phase analyses validated use of the technique for the descriptive analysis of PAH distribution in solid samples, but liquid-phase calibration was not quantitative for spiked or field-contaminated soils. The mean luminance for three field soils was proportional to the values predicted from their chemically measured concentrations and to values from spiked, aged, uncontaminated materials. Image analysis of laboratory- and field-contaminated samples determined the area distribution of fluorescent intensity and the size of fluorescent areas exceeding a threshold luminance. These qualitative descriptions of the microscale spatial distribution of PAH contamination are presented as potential endpoints for future research on biogeochemical interactions in heavily contaminated solids.

Hydrogen-Ion Concentration↗
PubMed1989

The correlation between uptake of methyl green and Feulgen staining intensity of cell nuclei. An image analysis study.

Paraffin sections of rat tissue fixed in either formaldehyde solution (3.6% w/v) or in Carnoy's fluid were stained using standardized Methyl Green-Pyronin procedures with the dyes used either simultaneously or in sequence. The sections were evaluated for the uptake of the two dyes by cell nuclei, nucleoli and cytoplasm using colour TV-image analysis. The parameters measured were integrated optical density and the surface area of the object. The sections were then destained and a Feulgen reaction was performed. The coordinates of the cells measured after the simultaneous Methyl Green-Pyronin method were stored in the computer, making it possible to measure the same cells in the Feulgen-restained sections. Image analysis gave results which invalidate the sequential methods as opposed to the simultaneous method. Mean optical densities were significantly increased for both dyes with the simultaneous method after formaldehyde fixation as compared to Carnoy fixation. The quantitative correlation of Methyl Green and DNA in the simultaneous technique was found to parallel exactly that of the Feulgen stain. In conclusion, the simultaneous Methyl Green-Pyronin technique is recommended while the sequential methods seem to be of less value.

Animals↗
PubMed1990

Use of a touch sensitive screen and computer assisted image analysis for quantitation of developmental changes in pulmonary structure.

The extensive changes in pulmonary function occurring during early development may reflect variations in the anatomic structure of the respiratory apparatus during this period. Accurate definition of these alterations could yield important information concerning the structure-function correlations of the respiratory system. To facilitate the acquisition of morphometric data from histologic sections of pulmonary tissues, we propose the use of a computer assisted image analysis system with a touch sensitive screen as an interactive peripheral. This allows planimetric measurements and computation of the dimensions of areas of selected light intensities within an image. We present the description, design, and applications of such an image analysis system and report representative results regarding developmental changes in pulmonary structure. In addition, we correlate these results with previously published information regarding pulmonary mechanics during early development to help clarify the maturational changes in pulmonary structure-function relationships.

Animals↗
PubMed2005

The combination of the Zenon labeling technique and microscopic image analysis to study cell populations in normal and psoriatic epidermis.

BACKGROUND: In order to better characterize epidermal cell populations in psoriatic vs. normal skin, fluorescent immunohistochemical techniques were extended with a new labeling technique. The Zenon technique conjugates primary antibodies rapidly and quantitatively after which they are used in the same manner as covalently labeled primary antibodies. Digital microscopic images of epidermal expression of keratin 10 and keratin 6 (differentiation), Ki-67 antigen (proliferation), and keratin 15 and beta-1 integrin (basal layer) were analyzed in a standardized way. Co-expression of different proteins was demonstrated. METHODS: Sections of normal skin and psoriatic lesions were compared immunohistochemically. Antibodies against keratin 6, 10, and 15 were labeled with the Zenon technique. Antibodies against the Ki-67 antigen and beta-1 integrin were covalently fluorescein isothiocyanate-labeled. Using standardized image analysis, intensity and positive surface area of the different antibodies in the epidermis were measured. RESULTS: The number of Ki-67-antigen positive cells was significantly increased in lesional psoriatic skin. Intensity and positive surface area of keratin 10 and beta-1 integrin were significantly decreased in comparison to normal epidermis. Differential expression of keratin 6 and keratin 15 was demonstrated. CONCLUSIONS: Using Zenon technology and image analysis, a description of morphology, co-expression, and quantification of representative markers for epidermal cell populations is possible.

Biomarkers↗
PubMed1990

[Various activities of the nucleolus organizer region in normal and leukemic bone marrow cells: semiquantitative data and computer- assisted image analysis by silver staining].

A cytochemical technique with silver nitrate staining was used to study the nucleolar organizer activity in metaphase spread of bone marrow cells from 13 patients with acute lymphocytic leukemia (ALL), 11 patients with chronic myelogenous leukemia (CML), 7 patients with acute myelogenous leukemia (AML), and 4 normal persons. Additionally, computer-assisted image analysis was used to quantitate the amount of silver staining in interphase nuclei of bone marrow cells from 6 untreated ALL patients, 3 normal subjects and 1 bone-marrow-transplant recipient. The results obtained have indicated that the nucleolar organizer reactivity (NOR) is significantly lower in the control group than that in ALL patients. NOR activity level is significantly lower in both CML patients in chronic phase, and AML patients than in the ALL group, and is similar to that in the control group. When the data obtained for the interphase nuclei were compared with those obtained for the metaphase spread, a strong correlation was recorded between the fraction of bone-marrow metaphases stained positively with silver, the average number of silver-positive nucleolar organizer regions per metaphase, and the amount of silver staining in the interphase nuclei. Silver staining used for the detection of these disease-related differences in NOR activity can serve as a diagnostic procedure in evaluating human leukemias. The computer-assisted image analysis of bone marrow cell interphase nuclei would be useful for more accurate resolving biological and medical problems.

Bone Marrow↗
PubMed1991

Image analysis microspectroscopy shows that neurons participate in the genesis of a subset of early primitive (diffuse) senile plaques.

Amyloid is a component of the senile plaques that characterize one of the major neuropathologic changes in patients with Alzheimer's disease (AD). The sequence of events leading to the accumulation of amyloid precursors in senile plaques is unknown. In previous studies, the authors have shown that congophilic deposits in a subset of mature amyloid plaques are angiocentric. In this study, the authors used image analysis microspectroscopy and an antibody directed against a synthetic beta-protein (beta) or A4 sequence to examine the distribution patterns of this protein in serial sections from brains of patients with AD and in normal aged brains after quantitative immunohistochemistry. Image analysis of early primitive plaques disclosed two main patterns of early beta/A4 deposition, which consisted of neurocentric and angiocentric decreasing concentration gradients. In most instances, these gradients were not recognizable by the naked eye but appeared strikingly conspicuous after image subtraction and pseudocoloring. The described neurocentric gradients suggest that deposition of this protein, in at least some early primitive plaques, is related to neurons and possibly originates from these cells. The opposite viewpoint, i.e., that peripherally synthesized beta/A4 protein would 'sink in' toward neurons, is not supported because in very early plaques the highest immunoreactivity within the gradient was the neuronal body itself. A hypothesis is offered to reconcile the presence of both neurocentric and angiocentric depositions of these substances.

Aged↗
PubMedDate not supplied

Computer image analysis of two-dimensional crystals of beef heart NADH: ubiquinone oxidoreductase fragments. I. Comparison of crystal structures in various negative stains.

We investigated the structure of two-dimensional crystals from bovine heart mitochondrial NADH: ubiquinone oxidoreductase. A detailed description of uranyl acetate-stained crystals demonstrated that they are composed of fragments in a spatial arrangement according to space group P4212 [J. Brink, S. Hovmöller, C.I. Ragan, M.W.J. Cleeter, E.J. Boekema and E.F.J. van Bruggen, European J. Biochem. 166 (1987) 287]. To gain more structural information on the crystal structure and to assess the effects of various negative stains on the structure preservation and appearance, we examined stained crystals by means of electron microscopy and image analysis. The space group P4212 appeared to be present for several stains tested, i.e. ammonium molybdate, uranyl acetate, uranyl nitrate and uranyl sulphate. Use of phosphotungstic acid and silicotungstate resulted in a reduction of symmetry to pseudo-P4212 or p4. Use of sodium tungstate led to a considerable loss of resolution to 3.8 nm at best, whereas otherwise 1.5 to 1.9 nm could be demonstrated. The lattice vectors were not affected by the stains; they were determined as a = b = 14.9 +/- 0.25 nm with gamma = 89.8 degrees +/- 0.6 degrees. Image analysis showed the presence of similar structures with the molybdate and uranyl compounds. Differences were observed in the case of the tungstate type of stains. Furthermore, the analysis revealed the complete absence of the four small pores of 2.0 nm diameter in the unit cell. This effect was observed irrespective of the type of stain and supporting film, and could be ascribed only to the glow-discharge treatment of the supporting film. The observed difference must be caused by changed interactions between the protein, stain and supporting film. Application of correspondence analysis and clustering algorithms to the various reconstructed images of the crystals showed that they could be separated into several clusters. Each of these clusters corresponded on the average to only one type of stain, whereas a further division according to the specific uranyl compounds was observed. This study therefore shows that under identical preparation conditions subtle differences between individual stains can be detected.

Animals↗
PubMed2005

Determination of an optimized conversion matrix for device independent skin color image analysis.

BACKGROUND AND OBJECTIVE: A cross-polarized diffuse reflectance (CDR) color imaging system was developed for quantitative evaluation of port wine stain (PWS) response to laser therapy. To obtain calibrated Commission International de l'Eclairage (CIE) color space images from RGB (red, green, and blue) images, it was necessary to derive an optimized conversion matrix specific to our imaging system. STUDY DESIGN/MATERIALS AND METHODS: A chromameter (CR-200, Minolta) and CDR imaging system were used to acquire CIELAB (CIE L*, a*, and b*) tristimulus values and RGB image values, respectively. A cost function was defined using these sample data sets and then a minimization algorithm was applied to obtain an optimized conversion matrix for our imaging system and illumination conditions. CIELAB color space values (L*, a*, and b*) obtained with the chromameter and CDR color images were compared to assess the accuracy of the derived matrix. RESULTS: In measurements using in vitro standard color patch or in vivo human skin samples, use of the optimized conversion matrix resulted in a good correlation with standard chromameter values for PWS human skin sites. CONCLUSIONS: The cost function minimization algorithm resulted in an optimized conversion matrix for our CDR imaging system. Use of the optimized matrix improved the utility of CDR color image analysis as a simple non-contact measurement technique to monitor quantitatively PWS response to laser therapy.

Color↗
PubMed1994

Ultrasound structure and digital image analysis of the subepidermal low echogenic band in aged human skin: diurnal changes and interindividual variability.

Subepidermal low-echogenic band is a consistent echostructural finding in aged and photodamaged skin. The thickness of subepidermal low-echogenic band is considered to closely reflect the degree of cutaneous aging and its use for the monitoring of the severity of photoaging and the efficacy of drugs is rapidly expanding. We investigated subepidermal low-echogenic band structure in 23 old healthy volunteers (ages 75-100) with a high-frequency ultrasound scanner (B-mode, 20 MHz). Images were collected from the volar fore-arm twice daily: in the morning before getting up and 12 h later. To assess the severity of subepidermal low-echogenic band, echogenicity of the subepidermal region was determined by the image analysis and compared with visual scoring and subepidermal low-echogenic band thickness. All three methods gave consistent results, image analysis being the most sensitive, reliable, and bias-free. Significant interindividual variability of subepidermal low-echogenic band echostructure was revealed. Moreover, circadian variability of subepidermal low-echogenic band echogenicity was observed. These major interindividual and diurnal variations of subepidermal low-echogenic band suggest that this band does not only represent an irreversible structural change but also a redistribution of fluid in the aged dermis. Diurnal variations in the subepidermal low-echogenic band would limit the use of this parameter in studies of skin aging, photoaging, and efficiency of medication.

Aged↗
PubMed1998

Identification of early apoptosis in feulgen-stained cultured cells in situ by computerized image analysis.

A method is presented in which Feulgen-stained apoptotic cells are identified among cultured cells in situ using computerized image analysis of their nuclei. Images of either control (untreated) human lymphoblastoid cell nuclei or of similar cells treated with 3mM methyl methanesulfonate for 1 h, which induces apoptosis in 100% of the cells, were converted to a standard size (80 x 80 pixels) and Fourier transforms and boundary images based on 21 proportional mean gray-level thresholds obtained. The perimeter and the mean fractal dimension of the latter and 39 selected coefficients of the former were then obtained from which data were chosen heuristically and subjected to multivariate linear discrimination analysis. Eighty-two percent of a teaching set of 50 nuclei and 69% of a test set of 29 nuclei were correctly identified as apoptotic versus nonapoptotic by the computer, compared with 57% identified correctly by a panel of 7 pathologists. This study shows the feasibility of using this type of analysis to directly identify apoptotic cells in culture, and probably also in tissues, by direct observation using computerized imaging technology.

Apoptosis↗
PubMed1998

Epiluminescence microscopy-based classification of pigmented skin lesions using computerized image analysis and an artificial neural network.

Epiluminescence microscopy (ELM) is a non-invasive technique for in vivo examination which can provide additional criteria for the clinical diagnosis of pigmented skin lesions (PSLs). In the present study we attempt to determine whether PSLs can be automatically diagnosed by an integrated computerized system. This system should recognize the PSL, automatically extract features and use these features in training an artificial neural network, which should--if sufficiently trained--be capable of recognizing and classifying a new PSL without human aid. One hundred and twenty images of randomly selected histologically proven PSLs (33 common naevi, 48 dysplastic naevi and 39 malignant melanomas) were used in this study. The images were digitally obtained and the morphological features of the PSLs were extracted electronically without human assistance. The numerical data were then divided into learning and testing cases and linked to an artificial neural network for training and for further classification of lesions that the system had not been trained on. Our results show that the computerized system was able to automatically identify 95% of the PSLs presented. The sensitivity and specificity of the computerized system were 90% and 74% respectively. In contrast, when differentiating between individual types of lesions, the system performed at true positive rates of only 38% for malignant melanoma, 62% for dysplastic naevi and 33% for common naevi. Our data indicate that (1) ELM images of PSLs provide an excellent source for digital image analysis; (2) the vast majority of PSLs can be correctly identified by a relatively simple (and thus not "intelligent") application of digital image analysis; (3) automatic feature extraction based mainly on ABCD rules provides reliable data on the distinction between benign and malignant PSLs; and (4) there is evidence that artificial neural networks can be trained to adequately discriminate between benign and malignant PSLs.

Dysplastic Nevus Syndrome↗
PubMed2003

Use of image analysis to determine algal and bacterial biomass in a high rate algal pond following Percoll fractionation.

This paper reports the results of work to allow a more accurate enumeration, and gravimetric determination, of the relative proportions of algae and bacteria within the floccular matrix present in a High Rate Algal Pond (HRAP). Methodology involving a combination of physical and chemical treatments was used and the resulting material was separated using density gradient centrifugation. The "fractions" were analysed using microscopical image analysis. Each "fraction" was categorised as containing bacteria only, algae only or an association of bacteria and algae, the relative proportions of which were then determined by image analysis to enable a "true" gravimetric determination of the algal and bacterial components of HRAP biomass for the first time. The biomass from HRAPs operated both outdoors and in a glasshouse was examined over complete operational seasons to investigate environmental effects as well as possible effects of variation in COD loading rate and retention time on cell biovolumes and cell quotients. In this study, the accurate assessment of both algal and bacterial biomass, determined as cell volume or dry matter, in addition to measurement of carbon and nitrogen has enabled the calculation of cell quotients. This allows a direct comparison between these values obtained from a nutrient-rich system and those published values obtained from systems with various nutrient status. Conversion factors obtained may also be of value for deriving inputs for computer models for the design and operation of high rate algal ponds.

Bacteria↗
PubMed2000

Quantitative assessment of angiogenesis and tumor vessel architecture by computer-assisted digital image analysis: effects of VEGF-toxin conjugate on tumor microvessel density.

Tumor growth is angiogenesis dependent. As a consequence, strategies aimed at disrupting this mechanism are heavily investigated. Several angiogenesis assays are used to directly compare the efficacy of anti-angiogenic compounds. However, objective assessment of new vascular growth has been difficult to achieve. The aim of this study was to test and develop a computer-assisted image analysis method that would give an unbiased quantification of the microvessel density. Human tumors were grown in athymic mice and tumor biopsies were taken after a weeklong treatment with VEGF-toxin conjugate. Frozen tumor sections were prepared and stained with PE-conjugated anti-CD-31 antibodies and vessels were imaged with a fluorescence microscope. Vessel density was analyzed by quantifying PE-positive pixels per recorded field. In addition, images were further processed to investigate morphological differences by an automated binarization and skeletonization protocol. This procedure allowed the computer-assisted estimation of important angiogenic parameters such as total vessel number, length, and branch points. Based on these indices, differences in the angiogenic response between control tumors and those treated with VEGF-toxin conjugate were readily detected (P < 0.007 for all parameters). More importantly, computer-generated measurements correlated well with manual microvessel counts and showed significantly less variation. Our results suggest that computer-assisted image analysis represents a rapid, objective, and alternative method for the quantitative assessment of tumor angiogenesis and vessel architecture.

Adenocarcinoma↗
PubMed1993

Subclinical human immunodeficiency virus-related changes in oral mucosa shown by image analysis of tongue smears.

There is evidence that certain lesions of the oral mucosa, such as hairy leukoplakia (HL), in patients seropositive for human immunodeficiency virus correlate with the subsequent development of acquired immune deficiency syndrome. The authors suggest that HL is a final manifestation of alterations that gradually develop after HIV infection. To recognize inapparent early subclinical changes in oral mucosa, the authors applied methods of digital image analysis to investigate tongue smears from healthy control subjects and immunosuppressed patients after chemotherapy and HIV infection. Their studies concentrated on nuclear morphologic features and chromatin structure. The results obtained with a large set of subvisual parameters indicated significant differences in nuclear and chromatin features between the smear patterns of investigated groups. One important implication of these studies is that computerized image analysis of simply prepared tongue smears enables one to recognize subvisual HIV-related changes before clinical evidence of HL appears.

Adult↗
PubMed1995

Image analysis DNA densitometry measurements on complete and partial hydatidiform mole and nonmolar products of conception.

Most spontaneous first trimester abortions have an abnormal karyotype, some being triploid; the latter are said to show characteristic histological changes, including focal villous hydropic change, focal trophoblast hyperplasia, cisternal cavitation of larger villi, irregular outline to villi, and trophoblast inclusions. To date, DNA-ploidy profiles have been derived from flow cytometry and cytogenetic karyotyping, both methods being time-consuming and expensive. This study has assessed DNA ploidy on products of conception using a simple video image analysis system. It is concluded that diploid, triploid, aneuploid, and hyperdiploid states can be ascertained on archival paraffin-embedded material using interactive image analysis morphometry. However, the stated histological criteria for triploidy (which has previously been equated with partial mole) appear to be unreliable, with only three of eight histological partial moles having this DNA pattern. In addition, there were six diploid, five triploid, seven hyperdiploid, and two aneuploid DNA ploidy profiles in the spontaneous nonmolar pregnancies. We found that of the 11 complete moles, five were aneuploid and six were hyperdiploid, with none being either diploid or triploid. This finding is contrary to the commonly held view that all complete moles have a diploid DNA profile.

Abortion, Missed↗
PubMed2000

Quantitative cytological assessment of Ki67 and AgNORs using computer-digitized image analysis of four clinicopathological breast lesions.

Analysis of silver-stained proteins associated with nucleolar organiser regions (AgNORs) is proposed as a marker of cellular proliferation. This study describes the application of AgNORs and Ki67 in breast lesions. Sixty-one cases including fibroadenoma (FA), fibrocystic disease (FCD), ductal carcinoma in situ (DCIS) and invasive carcinoma (IC) were studied by image analysis to evaluate quantitative changes in AgNORs in both Ki67-positive, and Ki67-negative smears. The Ki67 index was assessed. Morphometric features of cell nuclei and AgNORs were determined by digitized computer image analysis (Prodit 5.2). The growth fraction was 5.08 for FA, 5.71 for FCD, 16.75 for DCIS and 23.26 for IC. The mean nuclear area was significantly higher in malignant cells than those of fibroadenoma and fibrocystic disease. In Ki67-positive cells the total area, long axis and number of AgNORs increased progressively across disease groups. Eccentricity of AgNORs and AgNORs: nuclear area ratios were significantly increased in malignant breast lesion in comparison with benign lesion in Ki67 positive cells. In Ki67 negative cells, the highest value of AgNORs was observed in DCIS. The AgNORs: nuclear area ratio demonstrated a statistically significant trend across the disease groups. This study demonstrates that the growth fraction, mean nuclear area and selected AgNORs features have potential for differentiating benign from malignant breast tumours.

Breast Neoplasms↗