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Results for “Image Interpretation, Computer-Assisted”

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PubMed1992

Quantitative precision of an automated, fluorescence-based image cytometer.

Digital image-based cytometry of clinical specimens labeled with fluorescent, disease-specific markers holds promise for becoming an important diagnostic and prognostic technique because the technique can make a diverse range of quantitative biochemical, morphologic, densitometric and contextual measurements on intact specimens. It has been previously shown by us, using an image cytometer (IC) consisting entirely of commercially available components, that the nuclei of individual cells in slide-supported specimens can be detected automatically using a fluorescent DNA stain and image analysis software. The purpose of this study was to determine the precision of the IC for quantifying the integrated fluorescence intensity and area of fluorescent standard beads and nuclei. Integrated intensities could be quantified to between 2.3% and 3.5% precision using a 40x objective lens and between 1.6% and 2.3% using a 20x objective. The main contribution to this uncertainty was 2% inaccuracy in determining the variations in sensitivity over the imaging area. Areas could be quantified to between 0.91% and 2.1% using a 40x objective and between 2.8% and 3.2% using a 20x objective. Significant quantification errors were introduced if the objects were not in focus or were touching each other. Overall, however, these results demonstrated that image cytometry of fluorescence-stained specimens can yield quantitative results with sufficient precision for determining DNA ploidy distributions and for making other measurements on clinical specimens.

3T3 Cells↗

PubMed1992

Computed radiography.

Explore the source record for details and available documents.

Radiographic Image Interpretation, Computer-Assist↗

PubMed1992

The reliability of computerized cephalometric soft tissue prediction following bimaxillary anterior subapical osteotomy.

The accuracy of predicting the results of orthodontic-surgical treatment following bimaxillary anterior subapical setback osteotomy was analyzed retrospectively. Comparisons of pretreatment prediction tracings of the lateral cephalograms with the 6-month postsurgical cephalograms of 38 patients showed that there was no statistically significant difference between the actual and predicted dentoalveolar setback in both arches. The computer-generated soft tissue predictions were generally accurate, with the exception of the horizontal position of the lower lip, which was underestimated, and, to a lesser extent, the vertical position of the upper lip, which was also underestimated. Computerized cephalometric prediction following bimaxillary anterior subapical osteotomy is sufficiently accurate to be of value to be used routinely in treatment planning for the horizontal upper lip prediction, but some modifications are advisable to obtain a more accurate horizontal lower lip prediction.

Adult↗

PubMed1992

Line drawing analyses of static cervical X ray used in chiropractic.

OBJECTIVE: This review article identifies the chiropractic techniques used to assess the structure of the cervical spine as seen on the static cervical radiograph. DATA SOURCES: On-line search of MEDLINE, key words, radiograph and X ray in combination with cervical spine (vertebrae); the Chiropractic Research Archives Collection (CRAC); indexes published in the Journal of Chiropractic Research; conference proceedings from Annual Biomechanics Conference of the Spine, FCER sponsored conferences and Annual Upper Cervical Spine Conference; references identified from bibliographies of pertinent articles; a telephone poll of radiography/technique instructors at chiropractic colleges. STUDY SELECTION: Techniques that quantitatively assess relative alignment of skeletal structures or distortion of the spinal column. DATA EXTRACTION: Techniques were grouped according to the structures analyzed and the views used. DATA SYNTHESIS: Variables and artifacts that limit the reliability or validity of static cervical X ray line drawing analysis were identified and the techniques assessed for their reported reliability and validity. CONCLUSIONS: Reliability studies exist showing that inter- and intraexaminer reliability are sufficient to measure lateral and rotational displacements of C1 to within +/- 1 degree. This amount of error allows objective analysis of upper cervical X rays to detect changes in the angular positional relationships of radiographic images on the order of those already seen clinically. Methods of cervical analysis that use relative angular measures of skeletal positioning are best able to control the effects of radiographic distortion. The accuracy of the analysis methods has not been ascertained to establish the extent to which angular measurement of vertebral relationships actually reflect three-dimensional movement. It is not known how much of the changes that are seen in pre/post-radiograph sets are due to positioning changes of the patient between radiographic procedure, and how much are due to actual changes of skeletal relationships brought about by adjustment.

Cervical Vertebrae↗

PubMed1992

[Evaluation of the kinetics of the left ventricular wall using the Cardio 200 computer].

The WALLMO program was used in comparing normal kinetic values of left ventricle wall with those obtained from control patients and literature sources. Authors concluded that, when based on the original data for RAO projection, the evaluation of regional LV wall contractility gives erroneous results in estimating whether a given section is normo- hypo- or hyperkinetic. Therefore, the set of normal kinetic values of LV motion has been formed for individual numbers of radials. This set may be used also at other working sites.

Adult↗

PubMed1992

[Conventional roentgen functional diagnosis--videodensitometry. 1. Densitometric and topometric measurements of roentgen video images: technique and method of measuring].

It is possible to measure movements in the human body with the help of X-ray television systems. A great number of different techniques has been published in the scientific literature. They all based on only two principles with qualitative differences in signal acquisition. The densitometric and topometric measurements are assessed and compared. Neither the densitometric nor the topometric principle seems to be superior. To support the experimental work the videoanalyser VIANA MP was developed on the Ilmenau Institute of Technology.

Computer Systems↗

PubMed1992

[Conventional roentgen functional diagnosis--videodensitometry. 2. Clinical imaging site for noninvasive diagnosis of organ motion].

By means of the described system it is possible to measure and as well analog as digital process the organ movement, needing a X-ray television system for flouroscopy and a videotape for continuously recording. Using the densitometric principle measurements of time and a quantitative form analysis of the curves are performed. After border recognition and using the topometric principle, the local organ motion can be evaluated. The levels of signal and noise in the measured curves are computed by a fourier transformation. In the field of functional cardiology the video signal is recorded and processed synchronously with the electrocardiogram.

Computer Systems↗

PubMed1992

New metrics for analysis of dendritic branching patterns demonstrating similarities and differences in ON and ON-OFF directionally selective retinal ganglion cells.

The morphology and dendritic branching patterns of retinal ganglion cells have been studied in Golgi-impregnated, whole-mount preparations of rabbit retina. Among a large number of morphological types identified, two have been found that correspond to the morphology of ON and ON-OFF directionally selective (DS) ganglion cells identified in other studies. These two kinds of DS ganglion cell are compared with each other, as well as with examples of class I, class II, and class III cells, defined here with reference to our previous studies. Cell body, dendritic field size and branching pattern are analyzed in this paper and levels of dendritic stratification are examined in the following paper. ON DS ganglion cells are about 10% larger in soma size and about 5 times the dendritic field area of ON-OFF DS ganglion cells, when compared at the same retinal location. These two morphological types of ganglion cell can be said to define the upper and lower bounds of an intermediate range of cell body and dendritic field sizes within the whole population of ganglion cells. Nevertheless, in previous physiological studies receptive field sizes of the two types were shown to be similar. This discrepancy between morphological and physiological evidence is considered in the Discussion in terms of a model of the excitatory receptive field of ON-OFF DS ganglion cells incorporating starburst amacrine cells. A new set of metrics is introduced here for the quantitative analysis and characterization of the branching pattern of neuronal arborizations. This method compares the lengths of terminal and preterminal dendritic branches (treated separately), as a function of the distances of their origins from the soma, viewed graphically in a two-dimensional scatter plot. These values are derived from computer-aided 3D logging of the dendritic trees, and distance from the soma is measured as the shortest distance tracked along the dendritic branches. From these metrics of the "branch length distributions," scale-independent branching statistics are derived. These make use of mean branch lengths and distances, slopes of lines fitted to the distributions, and elliptical indices of scatter in the distributions. By these measures, ON and ON-OFF DS ganglion cells have similar branching patterns, which they share to varying degrees with functionally unrelated class III.1 ganglion cells. The scale of the branching patterns of ON and ON-OFF DS cells and their degree of uniformity are different, however.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed2026

Integrating histology and spatial transcriptomics via multimodal transformers and contrastive representation learning for accurate gene expression prediction.

Predicting spatial gene expression from Histological images is a fundamental task in understanding tissue organization and molecular phenotypes. However, existing methods often rely on single-model representations or lack effective alignment between image and transcriptomic features. To address these limitations, we propose a unified multimodal learning framework that integrates histological imaging and spatial transcriptomics through a shared latent representation space. Specifically, histological H&E images are encoded by a ResNet50-based convolutional stem and a MobileViT Transformer backbone to extract hierarchical visual representations. Both modalities are projected into a shared latent space via linear-GELU-dropout transformation blocks, enabling cross-modal alignment through a contrastive learning objective that maximizes agreement between the corresponding image and the spot embeddings. Experimental results on the 10x Genomics Visium dataset of human liver tissue demonstrate that MViTGene achieves significantly higher prediction accuracy than existing methods across multiple gene subsets, with improvements of 20%, 33%, and 12% in predicting marker genes, highly expressed genes, and highly variable genes, respectively. The significant improvement in relevance indicates that the model can more accurately capture the true correspondence between tissue morphology and gene expression, therefore enabling more reliable biological interpretation. It provides a computational tool for high-throughput spatial gene expression prediction that balances performance and interpretability.

Humans↗

PubMed1992

A two-step alignment method for 3D computer-aided reconstruction based on fiducial markers and applied to mouse embryonic hearts.

An accurate three dimensional computer reconstruction of microscopic biological objects or distribution of molecules identified on serial sections must solve two major problems: 1) the alignment of sections using adequate extrinsic references (fiducial markers); 2) the impossibility of observing these references and the cellular or molecular structures in the microscope at the same magnification. To provide extrinsic references for objects embedded in soft media, we have modified and simplified the charcoal-paraffin method described by Langemeijer and Simons (1973). It consists of drilling three or four small holes into the paraffin block, sealing this block at the extremity of a glass holder and, from the other extremity of the holder attached to a rubber hose, aspirating a liquefied mixture of charcoal-paraffin to fill these cylindrical holes. An alignment procedure was developed using serial sections of mouse embryonic hearts with bromodeoxyuridine-labelled DNA synthesizing cells. From each fourth section, two sets of contours have been drawn and digitized: 1) at low magnification (about 40x), embryo body wall, heart, neural tube and extrinsic reference marks (black dots); 2) at higher magnification (240-300x): heart contours alone (without extrinsic references, but with individual labelled cells). Different operations of the computer-aided alignment, as well as checking of results by inverse alignment, are described in detail. This two-step alignment method offers a practical, efficient compromise between: a) purely subjective alignment based only on tissular landmarks interpreted by the operator; b) ideal perfect alignment based not only on adequate references, but on computerized correction of section deformation, as well.

Animals↗

PubMed1992

Focal liver lesions: MR imaging with Mn-DPDP--initial clinical results in 40 patients.

Manganese (II) N,N'-dipyridoxylethylenediamine-N,N'-diacetate-5,5'-bis(phosphate) (DPDP) was evaluated as a contrast agent for magnetic resonance (MR) imaging (1.5 T) of focal liver lesions in 40 patients. Doses of 5 and 10 mumol/kg were administered intravenously. Mn-DPDP-enhanced T1-weighted images were compared quantitatively and subjectively with standard T1- and T2-weighted nonenhanced images. Use of Mn-DPDP resulted in a statistically significant increase in signal intensity of liver parenchyma in T1-weighted images at both doses. No enhancement was seen in metastases, cholangiocarcinomas, or lymphomas, while all hepatocellular carcinomas were enhanced. Enhancement was seen in focal nodular hyperplasia and in regenerative nodules. The lesion-to-liver contrast in Mn-DPDP-enhanced gradient-recalled-echo images was superior to that of all precontrast images (P less than .01). The number of nonenhancing malignant liver lesions detected in spin-echo (SE) images was increased (272 in T2-weighted SE images vs 390 in T1-weighted Mn-DPDP-enhanced SE images). Image interpretation (eg, visualization and demarcation of the lesions) was markedly better in Mn-DPDP-enhanced images than in all precontrast images (P less than .001).

Adult↗

PubMed1992

Three-dimensional crystallographic reconstruction for atomic resolution.

Three-dimensional structures have recently been determined by electron crystallography at a resolution high enough to determine atomic arrangements in both protein and mineral specimens. The different nature of these two types of specimens produces some very significant differences in the way data is obtained and processed, although the principles are the same. The sensitivity of proteins to damage by the electron beam limits the signal-to-noise ratio in the image and the resolution to which data can be extracted from the image. A number of constraints, such as the amino acid sequence and the connectivity of atoms within amino acids, can be used in interpreting the limited image data. In materials samples, the relative insensitivity to damage allows obtaining resolution limited only by the microscope. In many samples, dynamical scattering and other non-linear effects limit the information in the image, but this limit can be circumvented by working in very thin areas of the specimen.

Bacteriorhodopsins↗

PubMed1992

Evaluation of intracranial pressure gradients by means of transcranial Doppler sonography.

The authors investigated the effects of intracranial pressure gradients generated by a unilateral intracranial mass on transcranial Doppler (TCD) readings. Eleven patients harbouring a symptomatic chronic or subacute subdural haematoma underwent pre- and post-operative TCD examinations of the intracranial internal carotid and middle cerebral arteries. Mean values of velocity and pulsatility index (PI) were compared to the contra-lateral counterpart. The haematomas were evacuated by means of burr hole drainage under local anaesthesia. Symptomatic subdural haematomas lowered the ipsilateral blood velocity in the internal carotid and middle cerebral arteries by a mean side-to-side difference of 15.64 +/- 3.01 m.sec-1. The ipsilateral PI was higher than the contralateral values by an average of 0.23 +/- 0.04. Low mean velocity and high PI values were associated with high subdural pressure. Abnormal pre-operative ipsilateral TCD readings returned to normal following haematoma drainage. We postulate that intracranial pressure gradients generated by the subdural mass lesion are responsible for the asymmetry of TCD readings. These differences should be considered in the interpretation of post-subarachnoid haemorrhage vasospasm, as it is frequently associated with lateral clots. Our findings also provide a useful method for non-invasive monitoring of intracranial pressure gradients.

Adult↗

PubMed1992

Computer-aided analysis of DNA curves on transverse gradient gels.

Transverse pore gradient polyacrylamide gel electrophoresis of DNA restriction fragments was used to generate gel patterns describing migration distance as a function of gel concentration (Ferguson curves). These Ferguson curves were digitized, traced and analyzed with the aid of a personal computer. The traced curves were plotted semi-logarithmically and the plots were subjected to least-squares linear regression analysis to yield values of the slope (KR) and the intercept at %T = 0 (YO). These values are highly precise since they are based on approx. 100 measurements per curve. The computerized method reduces the errors due to manual measurements of migration distances and is time and labor saving. The method is still limited to intra-experimental comparison of Ferguson curves, since it does not as yet comprise a determination of gel concentration. At present, curve tracing remains semi-automated, requiring manual intervention when Ferguson curves cross or approach one another. Potentially, the importance of the computerized analysis of transverse pore gradient gels lies in the rapid quantitative interpretation of Ferguson curves for detection of anomalously migrating DNA species. Potentially, that application provides a more sensitive and informative mode of detection than either the mere visual observation of crossing Ferguson curves or of a shift in mobility at a single gel concentration.

Buffers↗

PubMed1992

Image processing system for interpreting motion in American Sign Language.

In this paper, an image processing algorithm is presented for the interpretation of the American Sign Language (ASL), which is one of the sign languages used by the majority of the deaf community. The process involves detection of hand motion, tracking the hand location based on the motion and classification of signs using adaptive clustering of stop positions, simple shape of the trajectory, and matching of the hand shape at the stop position.

Algorithms↗

PubMed1992

Cytometry in histological sections of colon carcinoma.

A short description of a project of cytometry in histological sections of colon carcinoma is given with emphasis on the methodical aspects. Possible strategies of cytometric measurement and problems related to it (focus, overlap, segmentation of objects) are described. The main effort concerns interactive selection of tumor cells and the segmentation in cases of densely distributed and overlapping nuclei. All other succeeding processing steps are performed fully automatically. The resulting quantitative features are stored together with the original images on an optical disk for further examinations and reexaminations, allowing the direct relation of feature values to visual image content. The evaluation of the features as well as their interpretation is only at the beginning. Especially the problem of relating section information with true 3-dimensional information is not described here and necessitates further research. In a first investigation only a few tumors without and with metastases were analyzed. The preliminary results correspond with findings of Kunze et al.

Cell Nucleus↗

PubMed1976

[Theory of image discernment and resolution of classification problems using medico-psychological methods].

The report deals with questions pertaining to the use of the theory of image discernment for solving psychodiagnostical problems in clinical practice. The traditional understanding of a psychological test as a measurement instrument is being opposed to its new interpretation as an instrument of classification. On this basis the authors described the successional stages of the general procedure in the elaboration of tests. Special attention is being drawn to the selection of primary signs with the aid of informational measures and the formation of scales as discriminators. The suggested approach is being illustrated on the model of elaborating scales of a personality questionnaire and intellectual techniques.

Diagnosis, Computer-Assisted↗

PubMed2020

Chemical Imaging of Retinal Pigment Epithelium in Frozen Sections of Zebrafish Larvae Using ToF-SIMS.

Variants of the SLC24A5 gene, which encodes a putative potassium-dependent sodium-calcium exchanger (NCKX5) that most likely resides in the melanosome or its precursor, affect pigmentation in both humans and zebrafish (Danio rerio). This finding suggests that genetic variations influencing human skin pigmentation alter melanosome biogenesis via ionic changes. Gaining an understanding of how changes in the ionic environment of organelles impact melanosome morphogenesis and pigmentation will require a spatially resolved way to characterize the chemical environment of melanosomes in pigmented tissue such as retinal pigment epithelium (RPE). The imaging mass spectrometry technique most suited for this type of cell and tissue analysis is time-of-flight secondary ion mass spectrometry (ToF-SIMS) because it is able to detect many biochemical species with high sensitivity and with submicron spatial resolution. Here, we describe chemical imaging of the RPE in frozen-hydrated sections of larval zebrafish using cryo-ToF-SIMS. To facilitate the data interpretation, positive and negative polarity ToF-SIMS image data were transformed into a single hyperspectral data set and analyzed using principal component analysis. The combination of a novel protocol and the use of multivariate data analysis allowed us to discover new marker ions that are attributable to leucodopachrome, a metabolite specific to the biosynthesis of eumelanin. The described methodology may be adapted for the investigation of other classes of molecules in frozen tissues from zebrafish and other organisms.

Animals↗