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At least 73 records · Page 4Linked to original sources
PubMed2003

Digitizing life at the level of the cell: high-performance laser-scanning microscopy and image analysis for in toto imaging of development.

The field of biological imaging is progressing at an amazing rate. Advances in both laser-scanning microscopy and green fluorescent protein (GFP) technology are combining to make possible imaging-based approaches for studying developmental mechanisms that were previously impossible. Modern confocal and multi-photon microscopes are pushing the envelope of speed, sensitivity, spectral resolution, and depth resolution to allow in vivo imaging of whole, live embryos at cellular resolution over extended periods of time. In toto imaging, in which nearly every cell in an embryo or tissue can be tracked through space and time during development, may become a standard technique for small transparent embryos such as zebrafish and early stage chick and mouse embryos. GFP and its spectral variants can be used to mark a wide range of in vivo biological information for in toto imaging including gene expression patterns, mutant phenotypes, and protein subcellular localization patterns. Combining in toto imaging and GFP transgenic approaches on a large scale may usher in an explosion of in vivo, developmental data as has happened in the past several years with genomic data. There are significant challenges that must be met to reach these goals. This paper will discuss the current state-of-the-art, the challenges, and the prospects of in toto imaging in the areas of imaging, image analysis, and informatics.

Animals↗
PubMed2001

[Automated image analysis of lateral roentgen images of the spine using anatomic models].

PURPOSE: Development of a software for fully automated image analysis of lateral lumbar spine X-rays. MATERIAL AND METHOD: Using the concept of active shape models, we developed a software that produces a form model of the lumbar spine from lateral lumbar spine radiographs and runs an automated image segmentation. This model is able to detect lumbar vertebrae automatically after the filtering of digitized X-ray images. The model was trained with 20 lateral lumbar spine radiographs with no pathological findings before we evaluated the software with 30 further X-ray images which were sorted by image quality ranging from one (best) to three (worst). There were 10 images for each quality. RESULTS: Image recognition strongly depended on image quality. In group one 52 and in group two 51 out of 60 vertebral bodies including the sacrum were recognized, but in group three only 18 vertebral bodies were properly identified. CONCLUSION: Fully automated and reliable recognition of vertebral bodies from lateral spine radiographs using the concept of active shape models is possible. The precision of this technique is limited by the superposition of different structures. Further improvements are necessary. Therefore standardized image quality and enlargement of the training data set are required.

Humans↗
PubMed1994

Computer assisted image analysis of bladder tumour nuclei for morphonuclear and ploidy assessment.

Morphonuclear analysis using a quantitative image analysis system has been demonstrated to be a potentially useful technique in the prognostic evaluation of bladder carcinoma. The integrated optical density parameter permits DNA content evaluation in addition to 15 other morphonuclear parameters. We assessed the reliability of morphonuclear analysis by image analysis and flow cytometry for 46 bladder carcinomas and 14 normal bladder specimens. Frozen sample material was obtained from endoscopic resection, radical cystectomy and from cadaveric donors. The grade and staging of the tumours according to the World Health Organization was as follows: 8 G1, 18 G2, 20 G3 and 28 T1, 7 T2, 7 T3, 4 T4. Quantitative image analysis was made on imprint smears stained by the Feulgen method. Simultaneously cell suspensions were obtained by mechanical dissociation and stained with propidium iodide for Flow cytometry analysis. There was a good agreement between quantitative image analysis and flow cytometry for DNA content measurement indicating that image analysis is a reliable method for the quantitation of DNA content (P = 0.001). Moreover we found a good correlation between five of the morphonuclear parameters: surface (P < 0.001), chromatin clumps distribution (P < 0.001), frequency of small (P < 0.001) to large chromatin clumps (P < 0.001) and the grade of bladder tumours. These results indicate that morphonuclear analysis may be a valuable method of quantitating DNA and morphonuclear parameters in a single analysis to provide information which may have some prognostic significance for patients with bladder carcinoma.

Cell Nucleus↗
PubMed1998

Computer-assisted densitometric image analysis of digital subtraction images: in vivo error of the method and effect of thresholding.

The aim of the present study was to assess the in vivo error of the method as well as the effect of thresholding when obtaining and evaluating standardized periapical radiographs for computer-assisted densitometric image analysis (CADIA). Twenty healthy volunteers participated in an experimental gingivitis study in which neither mechanical nor chemical plaque control was performed for 21 days. Two pairs of standardized periapical radiographs were taken at days 0 (baseline) and 21 (follow-up), one from a maxillary area (15 volunteers) and one from a mandibular molar/premolar area (17 volunteers). Each baseline radiograph was digitized and its image displayed on a monitor. The follow-up radiograph was then superimposed and digitized as well. After gray level correction, subtraction radiographic images were produced. The difference in gray level between the baseline and the follow-up image was calculated within each region of interest (ROI) at each picture point (pixel). In bone ROI, changes in density reflected the amount of change due to methodological errors plus the basic bone remodeling over 3 weeks. For gingival ROI, changes in density reflected the methodological error plus a possible change in soft tissue density during the experimental gingivitis. Within all of the ROI, some pixels indicated a change in gray level. A change in gray level was then thresholded; i.e., only changes >5 and then >10 gray levels were registered and used for calculation of the CADIA values. With a threshold of 5, 44/45 maxillary bone ROI and 60/66 mandibular bone ROI showed a change in density, while 41/45 maxillary gingiva ROI and 26/66 mandibular gingiva ROI indicated a change in density. With a threshold of 10, 16/45 maxillary bone ROI and 12/66 mandibular bone ROI indicated a change in density, while 13/45 maxillary gingiva ROI and 1/66 mandibular gingiva ROI indicated a change. The amounts of changes in density calculated in the various ROI were low even when applying no threshold, ranging from -0.279 to 0.621. Applying a threshold of 5, the CADIA values ranged from -0.234 to 0.727. With a threshold of 10, the changes in density ranged from -0.318 to 0.133. In vivo, CADIA of standardized radiographs indicated change in density due to methodological errors. Application of thresholds may avoid false-positive diagnoses. When applying CADIA in clinical research, the range of change to be expected due to methodological limitations as well as the threshold for true change should be evaluated. These thresholds may differ in various areas of the mouth, i.e., bone or gingival, maxillary/mandibular, anterior/posterior ROI.

Absorptiometry, Photon↗
PubMed1992

DNASK--a new image analysis module for TV image cytometry.

The DNASK is a PC-based image analysis module for quantitative cytological and histological examinations on Feulgen-Schiff preparations. The module consists of a frame grabber, a CCD black and white video camera and the DNASK software package which can be incorporated in an IBM compatible PC-AT joining to a standard pathological research photo microscope. The use of 386 IBM AT systems leads to significant decrease of the measurement's time. Mono- or color VGA graphics card should be used. The resolution of the images is 512 x 512 pixels and 256 gray values. The image caption is made in less than 0.5 second, the measurement of a cell nuclei (18 parameters) takes less, than 5 seconds (IBM AT 286). The camera is a standard CCD one. The microscope should be a good quality, modern microscope with built-in light source, however, the application of voltage stabiliser is strongly recommended. The software is able to measure the parameters mostly used and suggested in the international literature: 15 morpho- and densitometric parameters of the cell nuclei 6 DNA histogram parameters of the measured case, like DNA Index, 2c deviation Index, 5c exceeding rate, G1-S-G2 phase fraction ratio. The system supports the grouping of the measured cases and at the end of a study results of the single measurements can be collected and summarized in an ASCII file, which is readable by major statistical programpackages. The DNASK has a special graphical user interface for the control of the program.

Algorithms↗
PubMed1996

Automated cell cycle analysis with fluorescence microscopy and image analysis.

Automatic cell cycle analysis (DNA histograms) is usually performed with flow cytometry. In cases when only few cells are available, the DNA content has to be measured with a fluorescence microscope combined with sensitive camera systems (SIT, MCP, cooled CCDs) and a frame grabber for image analysis. The fluorescent cells are observed on the monitor of the image analyser. The DNA content of specific cells of interest is calculated after an interactive selection via mouse click on the monitor screen. It is desirable to automate this time-consuming procedure by a computer "cell-finding' and "cell-measurement' system, which is comparable in speed and measurement accuracy with manual scoring. A software program, based on image analysis, was designed for the automated cell finding, the cell measurement, and finally the interactive DNA data evaluation. The system has already been used to determine cell cycle stages in which specific manipulations of a lymphocyte culture were required. However, the system is also able to determine, automatically, DNA distributions of different kinds of cell (different leucocytes) within one sample, as long as the automatic recognition software can distinguish between them by morphological differences.

Algorithms↗
PubMed2000

Evaluating dot and Western blots using image analysis and pixel quantification of electronic images.

Inexpensive computer imaging technology was used to assess levels of insulin-like growth factor-I (IGF-I) on dot blots (DB) and alpha-Actinin on Western blots (WB). In the first procedure, known IGF-I samples were dotted on nitrocellulose membranes using a vacuum manifold. After the DB were developed and dried, the images were digitized using an HP Deskscan II flat bed scanner, exported into Image-Pro Plus and analyzed by taking the combined mean of 45 degrees and 135 degrees sample lines drawn through each dot. Dot blots corresponding to a linear concentration range from 10 to 300 ng IGF-I were assessed by this method. In the second procedure, WB were scanned with a ScanJet 3c flat bed scanner and their backgrounds were clarified using Image-Pro Plus. A second image analysis program, Alpha Imager 2000, was then used to define the boundaries of protein bands, assess pixel number and density, and to obtain final numerical data for quantifying alpha-Actinin on the WB. Collectively, the results of these two studies suggest that specific proteins may be evaluated by using relatively inexpensive image analysis software systems via pixel quantification of electronic images.

Actinin↗
PubMed2001

Imaging and detection technologies for image analysis in electrophoresis.

Image capture is the first step of image analysis. There are two major devices for image capture in the field of electrophoresis. One is the charged-couple device (CCD) camera and the other is the scanner. Image capture technologies have shown great progress in recent years especially in the field of fluorescence detection and chemiluminescent detection. The direction of image analysis is high resolution, wide dynamic range and high density precision and this holds true for the CCD camera system. Various components in the CCD camera system suitable for high-sensitive fluorescence detection and chemiluminescent detection are explained. As an example, the LAS-1000plus camera system which has 1364 x 922 pixels and generates 14-bits image is introduced. Powerful cooling enables overnight exposure of chemiluminescence. Introduction of blue light-emitting diode (LED) as excitation light source improved safety to eyes. Two types of scanners for fluorescence detection and the specific characteristics are explained. There are mechanical scanning systems using confocal optics and optical scanning systems using light collecting guide optics. Deep focusing range and equal fluorescence intensity at various depth is a characteristic feature of light collecting guide optics.

Computers↗
PubMed1993

Noninvasive quantitative evaluation of atherosclerosis using MRI and image analysis.

A new medical image analysis system to quantify atherosclerosis in the lower abdominal aorta using magnetic resonance imaging is described. This medical image analysis and display system permits the quantification of the three-dimensional (3D) properties of the vessel wall and lumen cross-sectional area and volumes. Preliminary results of employing this medical image analysis capability on magnetic resonance images demonstrated a twofold increase in wall volume per unit vessel length, corresponding to intimal thickening, before luminal narrowing was detected. This work demonstrated the feasibility and usefulness of quantitatively evaluating the 3D properties of the vessel lumen and wall by using a combination of magnetic resonance imaging and image analysis. The demonstration that intimal wall thickening is observed in images before observable occlusion of the lumen can be expected to provide an important early indicator of the future development of atherosclerosis. Such capability will permit detailed and quantitative studies to assess the effectiveness of therapies, such as drug, exercise, and dietary regimens.

Aorta↗
PubMed2005

Robust quantification of in vitro angiogenesis through image analysis.

An automated image analysis method for quantification of in vitro angiogenesis is presented. The method is designed for in vitro angiogenesis assays that are based on co-culturing endothelial cells with fibroblasts. Such assays are used in many current studies in which anti-angiogenic agents for the treatment of cancer are being sought. This search requires accurate quantification of the stimulatory and inhibitory effects of the different agents. The quantification method gives lengths and sizes of the tubule complexes as well as the numbers of junctions in each of them. The method is tested with a set of test images obtained with a commercially available in vitro angiogenesis assay. The results correctly indicate the inhibitory effect of suramin and the stimulatory effect of vascular endothelial growth factor. Moreover, the image analysis method is shown to be robust against variations in illumination. We have implemented a software package that utilizes the methods. The software as well as a set of test images are available at http://www.cs.tut.fi/sgn/csb/angioquant/.

Algorithms↗
PubMed1993

Measurement of colonic transit time using radionuclide imaging: analysis by condensed images.

A polymer-coated capsule has been used in eight volunteer subjects to deliver 111In-resin into the ileocaecal region. The images were acquired for up to 3 days to follow transit through the colon. Expressing the results of individual studies is difficult and time-activity curves for each region are confusing. Calculation of the geometric centre indicates only where the middle of the activity has reached. We describe a new method of presenting colonic transit data as parametric images. The parametric images show the amount of activity in each area of interest as the study progresses. This is readily understood and allows segmental movement of the isotope, either forward or retrograde, to be examined. The geometric mean of activity in four areas of the colon were also calculated. Four hours after reaching the ileocaecal region, 65% (S.D. 24%) of the activity was in the caecum and 26% (S.D. 20%) in the transverse colon. By 24 h three controls had excreted most of the activity, in two the activity was mainly in the rectum and in two there was still some activity in the transverse colon. A protocol for colonic transit studies, problems with analysis and a new method of presentation of data are discussed.

Acrylic Resins↗
PubMed1991

An image analysis on MR imaging of the brain for hepatic encephalopathy.

Through the Magnetic Resonance Imaging (MRI) sequences with T1 weighting (TR 600 msec/TE 20 msec) of the brain, the high intensity lesions due to hepatic encephalopathy have been demonstrated markedly. The data have been collected were based upon eleven patients with clinically proven hepatic encephalopathy. Three sets of normal brain MRI which were identified with no evidence of brain or liver diseases were also included in this study. After the brain MRI slices have been identified, it showed that the affected regions of interest (ROI) were around the largest third ventricle. The histogram which was generated out of that particular slice is composed of two distinguished peaks lumped together. After the decomposition and curve fitting procedures, the Gaussian distributions were identified with the mean value and the standard deviation. One was assumed to be gray index region for gray and white matter, the other with higher gray index value was the contribution of hepatic encephalopathy. Once the range of the distribution has been determined, the affected portion can be marked and highlighted. This mechanism of histogram decomposition and curve fitting techniques shows the valuable correlation with the clinical status of MR findings.

Brain↗
PubMedDate not supplied

Image analysis of catecholamine fluorescence.

Image analysis methods are being developed for measuring the density and distribution of perivascular noradrenergic nerves and their varicosities, demonstrated by fluorescence histochemistry. Image analysis is recommended in comparison with other methods for the quantitation of fluorescence, because image resolution is greater and larger areas of tissues can be scanned and measured more rapidly. Applications of image analysis have provided new and valuable information regarding sympathetic nerves: for example, we have shown rapid growth of perivascular nerves during perinatal development in the rabbit, and loss of nerves in different vessels in postnatal life and in old age; regional variations of nerve density and varicosity numbers in the central ear artery of the rabbit have also been demonstrated.

Adrenergic Fibers↗
PubMed1991

Mast cell fixation and staining in image analysis.

Modern image analysers automatically perform densitometric measurements and elaborate digital images. Elaboration however is subject to operator interpretation and often eliminates precious information from the areas of interest. For this reason, it was appropriate to find a staining method which would overcome this drawback and, in the case of mast cell histochemistry, limit staining to granule content. The following current staining techniques were tested: Toluidine Blue in buffered solution (solut. a) and in 0.003% alcoholic solution (solut. b) and alcoholic Astra Blue, pH 0.2 Densitometric analysis was performed on both 5 microns and semithin sections of mouse tongue fixed in Isotonic formaldehyde-acetic acid (IFAA). Digital images were obtained using 630 nm and 546 nm wavelengths for Toluidine Blue and 610 nm for Astra Blue. Direct comparison between the two Toluidine Blue solutions revealed that more pixels were captured by the 5 microns sections stained with solut. a, whilst the opposite occurred in semithin sections. Both dyes introduced a certain amount of error due to the orthochromatic component of the nucleus and cytoplasmic basophily, which had to be eliminated through image elaboration. Because of its subjective nature, this operation may in turn lead to further errors. The choice of Astra Blue as an alternative to Toluidine Blue in densitometric analysis of mastocytes is based on its property to restrict staining to the granules of mast cells. A comparison between Astra Blue and the two Toluidine Blue solutions showed that, at all transmission levels, preparations stained with Astra Blue captured more pixels than those stained with Toluidine Blue. Consequently our results suggest that the most suitable technique for densitometric image analysis is fixation of mast cells in IFAA followed with Astra Blue.

Animals↗
PubMed2006

Automated image analysis of atomic force microscopy images of rotavirus particles.

A variety of biological samples can be imaged by the atomic force microscope (AFM) under environments that range from vacuum to ambient to liquid. Generally imaging is pursued to evaluate structural features of the sample or perhaps identify some structural changes in the sample that are induced by the investigator. In many cases, AFM images of sample features and induced structural changes are interpreted in general qualitative terms such as markedly smaller or larger, rougher, highly irregular, or smooth. Various manual tools can be used to analyze images and extract more quantitative data, but this is usually a cumbersome process. To facilitate quantitative AFM imaging, automated image analysis routines are being developed. Viral particles imaged in water were used as a test case to develop an algorithm that automatically extracts average dimensional information from a large set of individual particles. The extracted information allows statistical analyses of the dimensional characteristics of the particles and facilitates interpretation related to the binding of the particles to the surface. This algorithm is being extended for analysis of other biological samples and physical objects that are imaged by AFM.

Algorithms↗
PubMed1997

Quality assurance in DNA image analysis on diploid cells.

DNA image analysis is presently performed in many laboratories. Before general extrapolation of results between different laboratories, validation has to be performed for interlaboratory studies on DNA image analysis. The aim of this study was to establish the performance of different DNA image analysis instruments when measuring different diploid cells. On three separate parts of the same object slide, human liver cells, white blood cells, and imprints of a breast fibroadenoma were sampled. In this quality assurance interlaboratory study, 13 laboratories participated voluntarily. Two slides were sent to each participating laboratory: one Feulgen and one unstained to be stained according the participating laboratory in-house procedure. The features integrated optical density (IOD) and object AREA were recorded for each nucleus. For calculation of the results, the average IOD value of liver diploid cells was set at 2c. A striking difference was observed between the different presumed diploid cell types, from almost 1c to 3c. This variation was not dependent on central or in-house staining. Although in-house calibration was performed for each image analysis system, a surprisingly large variation existed in the reported object AREA, irrespective of the cell type. These results clearly demonstrate that measurements performed in one laboratory cannot be extrapolated to the outcome of others and support the need for standardization. The use of external control cells works well for comparison of instruments. In conclusion, in DNA image analysis quality control is necessary, standardization is obligatory, and the use of an internal control for determination of the diploid peak in a histogram of patient samples is recommended.

Breast Neoplasms↗
PubMed1989

The PARTICLE expert system for tumor grading by automated image analysis.

While automated microscopic image analysis of histologic sections has been helpful in objectivizing histologic tumor grading and investigating the relationships between grading and prognosis, expert systems have the potential of linking image analysis and other data for statistical analysis and application to a wider range of tumors. One such expert system is PARTICLE, whose development was based on many years of experience in resolving histologic problems by image analysis. This paper discusses the philosophy of expert system for tumor grading and describes its implementation in the PARTICLE system. The system's structure, operations and applications are briefly presented. PARTICLE is essentially based on the evaluation of karyometric data.

Cell Nucleus↗
PubMed1994

Image analysis and synthesis of multimodal images in medicine.

Radiologic and clinical practice can be enhanced by improved access to multimodal image information. Analysis, visualization, method characteristic image processing and image synthesis is needed not only for the interpretation of the images but also for performing effective consultations with clinical colleagues and computer supported therapy planning and control strategies. A method is presented which enables the fast display, three-dimensional visualization and the modality oriented analysis of multimodal image information. Based on a unique image format, modality specific procedures and two- or three-dimensional processing tools of image analysis produce the input data for therapy planning programs. The easy use of this multimedia visualization tool enables radiologists and clinicians to deal with their image data. The description of methods and procedures, as well as typical examples of radiologic practice will demonstrate the efficiency of the presented system.

Algorithms↗