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PubMed1998

Morphometric analysis of pancreatic carcinoma by computer-assisted image analysis.

This report describes the results of applying the interactive image analysis system for the measurement of some cytological parameters corresponding to features of adenocarcinoma of the pancreas. The present experiments were carried out by means of the digital cell image analysis of haematoxilyn and eosin stained archival standard glass slides of cancer bearing and healthy patients. Four different parameters describing the morphology of nuclei and nucleoli were selected to quantitate the differences between control and malignant tissues: area, perimeter, elongation, and extension. The parameters that showed the greatest differences between cancerous and normal pancreas were: area and elongation in the case of nuclei as well as area and perimeter for nucleoli. However, the results of this study suggest that none of the four analysed parameters can be selected alone to discriminate neoplastic from normal cells, but could be used all together in diagnosis of pancreatic cancer.

Adenocarcinoma↗

PubMed2004

Incremental nature of anterior eye grading scales determined by objective image analysis.

AIM: To use previously validated image analysis techniques to determine the incremental nature of printed subjective anterior eye grading scales. METHODS: A purpose designed computer program was written to detect edges using a 3 x 3 kernal and to extract colour planes in the selected area of an image. Annunziato and Efron pictorial, and CCLRU and Vistakon-Synoptik photographic grades of bulbar hyperaemia, palpebral hyperaemia roughness, and corneal staining were analysed. RESULTS: The increments of the grading scales were best described by a quadratic rather than a linear function. Edge detection and colour extraction image analysis for bulbar hyperaemia (r2 = 0.35-0.99), palpebral hyperaemia (r2 = 0.71-0.99), palpebral roughness (r2 = 0.30-0.94), and corneal staining (r2 = 0.57-0.99) correlated well with scale grades, although the increments varied in magnitude and direction between different scales. Repeated image analysis measures had a 95% confidence interval of between 0.02 (colour extraction) and 0.10 (edge detection) scale units (on a 0-4 scale). CONCLUSION: The printed grading scales were more sensitive for grading features of low severity, but grades were not comparable between grading scales. Palpebral hyperaemia and staining grading is complicated by the variable presentations possible. Image analysis techniques are 6-35 times more repeatable than subjective grading, with a sensitivity of 1.2-2.8% of the scale.

Analysis of Variance↗

PubMed2001

Computerized image analysis as a tool to quantify infiltrating leukocytes: a comparison between high- and low-magnification images.

The purpose of the present study was to establish a rapid and reproducible method for quantification of tissue-infiltrating leukocytes using computerized image analysis. To achieve this, the staining procedure, the image acquisition, and the image analysis method were optimized. Because of the adaptive features of the human eye, computerized image analysis is more sensitive to variations in staining compared with manual image analysis. To minimize variations in staining, an automated immunostainer was used. With a digital scanner camera, low-magnification images could be sampled at high resolution, thus making it possible to analyze larger tissue sections. Image analysis was performed by color thresholding of the digital images based on values of hue, saturation, and intensity color mode, which we consider superior to the red, green, and blue color mode for analysis of most histological stains. To evaluate the method, we compared computerized analysis of images with a x100 or a x12.5 magnification to assess leukocytes infiltrating rat brain tumors after peripheral immunizations with tumor cells genetically modified to express rat interferon-gamma (IFN-gamma) or medium controls. The results generated by both methods correlated well and did not show any significant differences. The method allows efficient and reproducible processing of large tissue sections that is less time-consuming than conventional methods and can be performed with standard equipment and software.(J Histochem Cytochem 49:1073-1079, 2001)

Animals↗

PubMed2003

Image analysis and glare sensitivity in human age-related cataracts.

BACKGROUND: A new glare disability test and a diagnostic instrument, the Halometer, were proposed for measuring intraocular light scattering in the presence of human cataracts. The objectives of this work were to introduce new methods of computer-generated analysis of lens images and a glare disability test to validate the use of two new tests to measure the severity of cataract and to document and quantify changes in lens clarity at diagnosis in a group of patients with age-related cataract with minimal to advanced opacities. METHODS: The authors followed 28 patients (46 eyes) with an average age of 66.9 +/- 6 years. Tests included ophthalmoscopy, visual acuity, the halometer glare disability test, stereocinematographic slit-image and retro-illumination photography with subsequent interactive digital image analysis and three-dimensional (3-D) computer graphics of the areas of lens light scattering/absorbing. RESULTS: The intra-reader reproducibility of measuring techniques for cataractous changes was good. The Halometer instrument measures the angular distance from the glare source from which a specific target can be recognised. The source and the target are in the same vertical and tangential planes and to measure the angular distribution of the glare light, it is necessary to measure the incident light angle between the source and the target, by measuring the distance between the source and the target. The clinical Halometry readings assessed the index of the forward scattered light that reaches the retina and produces a veiling luminance (glare). The glare sensitivity score was determined from the angle of the glare source using both red and green optotypes, so that the effects of light absorption were separated from those of light scatter. DISCUSSION: The interactive and automated computerised system discriminated the photographic image features of the back light-scattering/absorb centres within different grey thresholds and documented objective lens findings such as optical density, areas of equidensities, geometric surfaces, opacity grading. Digital image analysis gave a topographic and 3-D assembling and visualisation for nuclear, cortical and posterior subcapsular opacities in human lenses revealed from the optical scanning tomographic study of the anterior eye segment. The results indicate on agreement between clinical findings and applied quantitative techniques of analysis. This system has the potential to be a useful objective clinical assessment of cataract.

Aged↗

PubMed1994

Digital imaging colposcopy, image analysis and quantification of the colposcopic image.

OBJECTIVE: To investigate the use of a digital imaging system for colposcopy, its use for image analysis and quantification of the colposcopic features that may predict histological outcome as defined by large loop excision of transformation zone. DESIGN: Prospective programme study of all patients undergoing colposcopy for cytological abnormalities. SETTING: Dudley Road Hospital, Birmingham. SUBJECTS: Fifty consecutive patients having cytological and colposcopic abnormality treated with large loop excision of transformation zone formed the study group. MAIN OUTCOME MEASURES: Pretreatment and colposcopic features correlated with histological diagnosis of excised transformation zone. RESULTS: Index cytology and current smoking status are the most important variables for prediction of histological diagnosis. Other important variables are focality of lesion, surface pattern, intercapillary distance and degree of acetowhiteness. CONCLUSION: Digital imaging colposcopy allows image capture, processing and objective analysis. This methodology holds advantages for basic and clinical research, teaching, diagnostics and clinical audit. The system can act as a quality control tool for colposcopy units. This system should prove invaluable for further quantitative studies, for natural history studies and for those patients with deferred treatment of their cytological and colposcopic abnormalities. The statistical models described may be incorporated into the system and can aid the colposcopist in management of the woman with abnormal cervical cytology and colposcopic abnormality.

Adolescent↗

PubMed2003

[Application of image analysis system to the study of biomedicine].

Image analysis plays an important role in morphological study of tissues and cells and their quantitative analysis. It also contributes to clinical pathological diagnosis. With the rapid development of computer technology great progress has been made in the image analysis system, its measurement, rapidity, accuracy and the extent of automation have been greatly enhanced. In the meantime advances in medicine give impetus to its improvement. In this paper, the process of development, the basic structure and mechanism of image analysis system are discussed and the application of image analysis system to the study of biomedicinal is presented.

Image Processing, Computer-Assisted↗

PubMed2007

Changes of contrast-specific ultrasonic cerebral perfusion patterns in the course of stroke; reliability of region-wise and parametric imaging analysis.

Ultrasound perfusion imaging (UPI) reliably detects size and localization of acute stroke. It remains unclear which time window detects, most sensitively and specifically, early changes of cerebral perfusion patterns and whether region-wise analysis is superior to parametric imaging analysis. Bilateral phase inversion harmonic imaging examinations (bolus kinetic, fitted model function) were performed twice (acutely and 28 h later) in 10 patients with acute ischemic stroke (<12 h). Examinations were evaluated using a region-wise analysis of the time-intensity curve and by parametric images of the time-to-peak intensity maps. Results were correlated in-between the ultrasound examinations and to follow-up cranial computed tomography (CCT) scans. Correlation between the early region-wise UPI examination and follow-up CCT was the strongest (Spearman correlation coefficient 0.76, sensitivity 84%, specificity 96%). Spearman coefficient between the late UPI examination and CCT was 0.51; sensitivity and specificity were 71% and 82%. Values in between UPI examinations were 57% and 88%, with a Spearman coefficient of 0.47 (p for all < 0.001). Values of the analysis of the parametric images were less strong. Concordance between both of the UPI methods was 65% in the early examination and 72% in the late examination. Changes of perfusion patterns are most accurately detected in the early course of stroke, when core of infarction can be differentiated from penumbra and viable tissue. Reperfusion phenomena may impair the diagnostic impact in later examinations. Parametric imaging does not yet seem to be as accurate as region-wise analysis.

Acute Disease↗

PubMedDate not supplied

IMPROMPTU: a system for automatic 3D medical image-analysis.

The utility of three-dimensional (3D) medical imaging is hampered by difficulties in extracting anatomical regions and making measurements in 3D images. Presently, a user is generally forced to use time-consuming, subjective, manual methods, such as slice tracing and region painting, to define regions of interest. Automatic image-analysis methods can ameliorate the difficulties of manual methods. This paper describes a graphical user interface (GUI) system for constructing automatic image-analysis processes for 3D medical-imaging applications. The system, referred to as IMPROMPTU, provides a user-friendly environment for prototyping, testing and executing complex image-analysis processes. IMPROMPTU can stand alone or it can interact with an existing graphics-based 3D medical image-analysis package (VIDA), giving a strong environment for 3D image-analysis, consisting of tools for visualization, manual interaction, and automatic processing. IMPROMPTU links to a large library of 1D, 2D, and 3D image-processing functions, referred to as VIPLIB, but a user can easily link in custom-made functions. 3D applications of the system are given for left-ventricular chamber, myocardial, and upper-airway extractions.

Computer Graphics↗

PubMed1998

A review of caveats in statistical nuclear image analysis.

A large body of the published literature in nuclear image analysis do not evaluate their findings on an independent data set. Hence, if several features are evaluated on a limited data set over-optimistic results are easily achieved. In order to find features that separate different outcome classes of interest, statistical evaluation of the nuclear features must be performed. Furthermore, to classify an unknown sample using image analysis, a classification rule must be designed and evaluated. Unfortunately, statistical evaluation methods used in the literature of nuclear image analysis are often inappropriate. The present article discusses some of the difficulties in statistical evaluation of nuclear image analysis, and a study of cervical cancer is presented in order to illustrate the problems. In conclusion, some of the most severe errors in nuclear image analysis occur in analysis of a large feature set, including few patients, without confirming the results on an independent data set. To select features, Bonferroni correction for multiple test is recommended, together with a standard feature set selection method. Furthermore, we consider that the minimum requirement of performing statistical evaluation in nuclear image analysis is confirmation of the results on an independent data set. We suggest that a consensus of how to perform evaluation of diagnostic and prognostic features is necessary, in order to develop reliable tools for clinical use, based on nuclear image analysis.

Data Interpretation, Statistical↗

PubMed1997

Roentgen stereophotogrammetric analysis using computer-based image-analysis.

The two-dimensional position of markers in radiographs for Roentgen Stereophotogrammetric Analysis (RSA) is usually determined using a measuring table. The purpose of this study was to evaluate the reproducibility and the accuracy of a new RSA system using digitized radiographs and image-processing algorithms to determine the marker position in the radiographs. Four double-RSA examinations of a phantom and 18 RSA examinations from six patients included in different RSA-studies of knee prostheses were used to test the reproducibility and the accuracy of the system. The radiographs were scanned at 600 dpi resolution and 256 gray levels. The center of each of the tantalum-markers in the radiographs was calculated by the computer program from the contour of the marker with the use of an edge-detection software algorithm after the marker was identified on a PC monitor. The study showed that computer-based image analysis can be used in RSA-examinations. The advantages of using image-processing software in RSA are that the marker positions are determined in an objective manner, and that there is no need for a systematic manual identification of all the markers on the radiograph before the actual measurement.

Arthrography↗

PubMed1987

The effect of inhaled leukotriene D4, histamine, or antigen on central and peripheral airways of guinea pigs: analysis of bronchograms with an interactive image analysis system.

The effect on guinea pig airways of the inhalation of leukotrienes, histamine or antigen was investigated by measuring changes in lung volume and analyzing the airway area on bronchograms with the Zeiss interactive image analysis system (IBAS). LTC4, LTD4, LTE4 and histamine inhaled through an ultrasonic nebulizer caused inflation of the lung: LTD4 was the most potent of the leukotrienes and was 100 times more potent than histamine on a molar basis. The results of analyses of areas of large and small bronchi and bronchioles on the bronchograms indicated that LTD4 selectively decreased the area of the peripheral airways. Inhalation of an antigen in actively sensitized animals resulted in inflation of the lung and in a selective decrease in the area of the peripheral airways. Anaphylactic bronchoconstriction provoked by antigen inhalation was clearly inhibited by AA-861, a 5-lipoxygenase inhibitor but not significantly by mepyramine, an antihistamine. These observations indicate that LTD4 is a potent constrictor of the peripheral airways in guinea pigs and that the anaphylactic bronchoconstriction provoked by antigen inhalation could be mediated by LTD4 in actively sensitized guinea pigs.

Anaphylaxis↗

PubMed2004

Technical note: A toy as tool: a low-cost image analysis system for the evaluation of tumor size in experimental small animal models.

Image analysis systems are an essential tool in measurements of size of intraparenchymal tumors or lesions in experimental small animal models. Conventional image analysis systems are relatively expensive. We therefore compared the performance of a professional image analysis system with an inexpensive setup by evaluating tumor size in an orthotopic glioma mouse model. The maximum cross-sectional tumor area of H&E stained brain-slides of two groups of mice (treatment and control group) was measured by two independent investigators using a professional image analysis system (Leica DM IRB microscope) with the Leica Quantimet 500c software, and a low-cost-system (Intel QX3 microscope) with a non-commercial image analysis software. Mean tumor volumes were calculated and the results from each of the image analysis systems, investigators, and treatment effects were compared. The tumor volumes as measured with the low-cost and the professional system differed between -3.7 and +7.5% (P = 0.69-0.99). Measurements made by investigator A and B differed between -7.0 and +3.9% (P = 0.69-0.88). Treatment in all cases significantly reduced the tumor volume between 58.4 and 62.7% (P = 0.0002 or 0.0003), regardless of the investigator or the used image analysis system. We therefore conclude that the QX3 low-cost microscope in combination with a non-commercial image-analysis software represents an inexpensive solution to reliably analyze the size of regions of interest, if they provide a sufficient contrast. However, the low-cost setup due to its low resolution definitely limits a detailed analysis of histologic features.

Animals↗

PubMed1992

Biotechnological applications of image analysis: present and future prospects.

The current and potential biotechnological applications of image analysis and image processing systems are reviewed. Image analysis systems have proven to be highly versatile and efficient tools for assisting academic biotechnological research. It is expected that image analysis systems will allow more rapid and accurate quantification of numerous biotechnological analyses. There is, therefore, much scope for the implementation of image analysis/processing systems in a large variety of industrial and clinical applications.

Animals↗

PubMed1993

Quantitation of smooth muscle proliferation in cultured aorta. A color image analysis method for the Macintosh.

Color image analysis was used to assess proliferative changes in smooth muscle cells from cultured segments of rabbit aortas. Proliferating cells were labeled with bromodeoxyuridine (BrdU) and visualized by immunohistochemical staining of histologic sections. A Macintosh IIfx computer with a Data Translation digitizer board, Javelin color camera and a color-enhanced version of National Institutes of Health Image 1.31 image analysis software (ColorImage 1.31) was used to acquire red, green and blue (RGB)-filtered grayscale images from microscopic slides of control and treated aortas. The BrdU-labeled (brown) and nonlabeled, hematoxylin (blue)-stained nuclei were identified on the RGB gray-scale images using a thresholding technique and sampled for nuclear number and area. An increase in the number of BrdU-labeled nuclei in the region of experimental perturbation was demonstrated by this semiautomated method. Thus, this Macintosh-based color image analysis method proved to be effective in rapidly quantitating immunohistochemically defined smooth muscle proliferation in microscopic tissues.

Animals↗

PubMed1995

Developmental changes in the prothoracicotropic hormone content of the Bombyx mori brain-retrocerebral complex and hemolymph: analysis by immunogold electron microscopy, quantitative image analysis, and time-resolved fluoroimmunoassay.

The insect brain neuropeptide, prothoracicotropic hormone (PTTH), elicits the molting process by stimulating ecdysteroidogenesis in the prothoracic glands. Changes in the subcellular distribution of PTTH during the fifth larval instar and larval-pupal metamorphosis of Bombyx were investigated using immunogold electron microscopy and computerized image analysis. A time-resolved fluoroimmunoassay was employed to quantify the hemolymph PTTH titer and the hemolymph ecdysteroid titer was determined by radioimmunoassay. Immunoreactivity was apparent only in the cytoplasm of two pairs of dorsal-lateral neurosecretory cells (La) in the brain, the prothoracicotropes, and their axons that traverse the peripheral area of the brain neuropil and then enter the neurohemal lobes of the corpora cardiaca and end in the corpora allata. Immunospecificity was evident as noted by the restriction of the 5-nm gold particles to the neurosecretory granules. Synaptic contacts were noted frequently between the dendritic collaterals of the prothoracicotropes and neighboring collaterals from other neurons. The morphological data suggest that PTTH is synthesized and released throughout the fifth larval instar. The concentration of gold particles in the neurosecretory granules and the number of neurosecretory granules increased five times during the fifth instar, and these increases were correlated with surges in the hemolymph PTTH and ecdysteroid titers. The data suggest that PTTH biosynthesis, secretory granule formation, and secretion are three continuous and almost synchronized events.

Amino Acid Sequence↗

PubMed2001

A simple stereologic method for analysis of cerebral cortical microvessels using image analysis.

Previous methods for determining morphological features of vascular networks in cerebral cortex were subject to arbitrary variation and bias. Unbiased estimates of vessel number, volume, surface area and length can be obtained using stereology but these techniques tend to be tedious and time-consuming. Stereologic protocols generally require micrographs that have to be analyzed manually for intersections of vessels on grid points or lines. In this report, we provide a simpler and more precise method for measuring morphological features of cerebral cortical microvessels. Images of microvessels in 1 microm toluidine blue stained sections were captured using a popular image analysis software package. Luminal surfaces of endothelial cells were automatically traced using commonly available features; the two-dimensional data of vessels (diameter, area, perimeter and number of vessels) were automatically computed and transferred to a spreadsheet. Three-dimensional features were then determined using basic stereologic equations. The method eliminates the need for manual measurements and is particularly time- and cost-effective for quantitative studies where numerous images have to be evaluated.

Animals↗

PubMed2000

Image analysis methods for assessing levels of image plane nonuniformity and stochastic noise in a magnetic resonance image of a homogeneous phantom.

Magnetic response image plane nonuniformity and stochastic noise are properties that greatly influence the outcome of quantitative magnetic resonance imaging (MRI) evaluations such as gel dosimetry measurements using MRI. To study these properties, robust and accurate image analysis methods are required. New nonuniformity level assessment methods were designed, since previous methods were found to be insufficiently robust and accurate. The new and previously reported nonuniformity level assessment methods were analyzed with respect to, for example, insensitivity to stochastic noise; and previously reported stochastic noise level assessment methods with respect to insensitivity to nonuniformity. Using the same image data, different methods were found to assess significantly different levels of nonuniformity. Nonuniformity levels obtained using methods that count pixels in an intensity interval, and obtained using methods that use only intensity values, were found not to be comparable. The latter were found preferable, since they assess the quantity intrinsically sought. A new method which calculates a deviation image, with every pixel representing the deviation from a reference intensity, was least sensitive to stochastic noise. Furthermore, unlike any other analyzed method, it includes all intensity variations across the phantom area and allows for studies of nonuniformity shapes. This new method was designed for accurate studies of nonuniformities in gel dosimetry measurements, but could also be used with benefit in quality assurance and acceptance testing of MRI, scintillation camera, and computer tomography systems. The stochastic noise level was found to be greatly method dependent. Two methods were found to be insensitive to nonuniformity and also simple to use in practice. One method assesses the stochastic noise level as the average of the levels at five different positions within the phantom area, and the other assesses the stochastic noise in a region outside the phantom area.

Image Processing, Computer-Assisted↗

PubMed2000

Quantitative DNA and morphometric analysis of gastroscopic brush smears by TV image analysis.

OBJECTIVES: To determine quantitative nuclear morpho-and densitometric classifiers and classification techniques for analysis of gastric, Feulgen-stained brush smears. DESIGN: TV image analysis-based quantitative DNA and morphometric analysis of gastric brush smears in a prospective study. PATIENTS AND METHODS: Ninety-eight (11 normal, 77 gastritis (17 with intestinal metaplasia) and 10 adenocarcinoma) Feulgen-Schiff-stained gastric brush smears were analysed by TV image analysis. The classification of the smears was based on parallel histological examination. For standards, DNA content of lymphocyte cell cultures was determined by the image and by flow cytometry. From every nucleus, six morphometric (surface, layers, minimum diameter, maximum diameter, perimeter and form factor) and six densitometric (integrated optical density (IOD), average density, sigma density, minimum and maximum density and density range) parameters were simultaneously determined. The smear parameters (object cells CV, DNA index, 2c deviation index, 5c exceeding rate, G1 -S-G2 ratio) were analysed together with the mean and SD values of the nuclear parameters by discriminant analysis and back-propagation neural networks. RESULT: The normal smears were all diploid and their S + G2 ratio was 15.24+/-7.75% (mean +/- SD). The gastritis smears were all diploid with a proliferation fraction of 20.89+/-6.75%. The tumours were aneuploid in eight of the ten cases with 5c exceeding rate > 6.23%, the S + G2 fraction ratio was 34.72+/-10.12%. The mean nuclear surface area was 46+/-20, 58+/-20 and 74+/-22 microm2 in normal, gastritis and malignant groups, respectively. Significant differences (P<0.05) were found in nuclear surface, minimum and maximum diameter, and perimeter parameters. Using linear discriminant analysis, 100% of the non-malignant cases and 70% of the tumour cases were correctly classified. Using 30 non-malignant and five malignant cases as a training set, the neural networks classified 95% of the remaining cases correctly. The DNA index increased significantly (P<0.05) in Helicobacter pylori-positive cases compared to the negative ones. In gastritis with intestinal metaplasia, the proliferation ratio decreased significantly (P<0.05). CONCLUSIONS: The image analysis is a useful tool for quantitative gastric cytology. The combination of nuclear morphometric parameters and neural network classifiers with multivariate quantitative DNA analysis is suggested for gastric brush smear quantitative cytology analysis.

Adenocarcinoma↗