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Results for “Image Interpretation, Computer-Assisted”

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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↗

PubMed2024

Digital pathology and spatial omics in steatohepatitis: Clinical applications and discovery potentials.

Steatohepatitis with diverse etiologies is the most common histological manifestation in patients with liver disease. However, there are currently no specific histopathological features pathognomonic for metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, or metabolic dysfunction-associated steatotic liver disease with increased alcohol intake. Digitizing traditional pathology slides has created an emerging field of digital pathology, allowing for easier access, storage, sharing, and analysis of whole-slide images. Artificial intelligence (AI) algorithms have been developed for whole-slide images to enhance the accuracy and speed of the histological interpretation of steatohepatitis and are currently employed in biomarker development. Spatial biology is a novel field that enables investigators to map gene and protein expression within a specific region of interest on liver histological sections, examine disease heterogeneity within tissues, and understand the relationship between molecular changes and distinct tissue morphology. Here, we review the utility of digital pathology (using linear and nonlinear microscopy) augmented with AI analysis to improve the accuracy of histological interpretation. We will also discuss the spatial omics landscape with special emphasis on the strengths and limitations of established spatial transcriptomics and proteomics technologies and their application in steatohepatitis. We then highlight the power of multimodal integration of digital pathology augmented by machine learning (ML)algorithms with spatial biology. The review concludes with a discussion of the current gaps in knowledge, the limitations and premises of these tools and technologies, and the areas of future research.

Humans↗

PubMed1978

Dual radionuclide study of acute myocardial infarction: comparison of thallium-201 and technetium-99m stannous prophosphate imaging in man.

We evaluated dual imaging with thalium-201 (201TI) and technetium-99m (99mTc) pyrophosphate in 80 patients with documented acute myocardial infarction (55 transmural, 25 nontransmural infarction). Color-coded isocount display of 201TI images was essential for interpretation in 16 patients. Combined 201 TI and 99mTc-pyrophosphate imaging for infarct detection was 100% sensitive; however, either was falsely negative in 12 of 80 patients. False-negative individual 201TI or 99mTc-pyrophosphate infarct images were most common in patients with small infacts or left ventricular hypertrophy. Thallium-201 images correctly localized the site of acute transmural infarction in all 51 patients with a positive image, while 99mTc-pyrophosphate localized the site of infarction in 49 of 53 with an abnormal image. Comparison of the size of the imaged infarct region revealed size discordance in 25 of 49 patinets, with 99mTc-pyrophosphate larger in 21 of 49 and 201TI larger in only four of 49. Thus dual radionuclide imaging provides definition of the presence and location of acute myocardial infarction.

Acute Disease↗

PubMed1976

Methods for measurement of cerebral blood flow in man.

A survey of the currently available methods for the measurement of cerebral blood flow in man is given. Many of the clinically important brain diseases such as tumors, stroke, brain trauma or epilepsy entail focal or regional flow alterations. Therefore a special emphasis is placed on methods allowing measurements of regional cerebral flow, rCBF. The intra-arterial 133Xenon injection method is now widely used as a standard method for rCBF measurement. It affords a good two-dimensional resolution when using a suitable dynamic gamma camera which allows a high counting rate to be recorded. But, due to the superposition of tissues the three-dimensional resolution is limited. This, in particular, means that smaller areas of ischemia (low flow) tend to be overlooked whereas local hyperemia is readily discerned. The 133Xenon inhalation method is less accurate, contaminated by extra-cerebral uptake, and insensitive both for detecting regional ischemia and regional hyperemia. The spatial resolution is also much more limited. For these reasons great caution must be exercised in interpreting the results. Methods yielding three-dimensional rCBF data will be needed in order to gain more precise information both on spatial localization and, especially, on ischemic areas. The most promising is computer-assisted axial tomography with freely diffusible radioactive isotopes or with x-rays using an intra-arterial injection of contrast. But, the available techniques are still too slow: in order to measure blood flow one "exposure" must be taken every second. Only a few methods give quantitative information of the blood flow in the human brain. This is mainly due to the inaccessibility of the brain within the skull and to the complexity of the cerebral arterial and venous systems. Before reviewing the various methods used in man, it should be mentioned, that much of the fundamental knowledge has been gained by methods only applicable to animals. Measurements of the diameter of the small arteries on the surface of the brain antedates even the classical studies of Roy and Sherrington (1890). This technique continues to be useful, modern technical improvements consisting of the use of micropipettes and a stereo microscope in combination with an image splitter and a television camera which allows the accurate assessment of diameter variations of a few percent [22]. Autoradiography of brain slices using diffusible indicators is the best quantitative method for measuring local blood flow in a great many parts of the brain [7, 45]. Microspheres are also being used, but it is still not quite clear that this technique gives reliable quantitative data in small masses of tissue [34, 41, 50].

Animals↗

PubMed1992

The genesis of the senile plaque. Further evidence in support of its neuronal origin.

Senile plaques are among the most conspicuous neuropathologic changes found in the brains of elderly individuals and patients with Alzheimer's disease (AD). The origin of the amyloid beta protein (A beta P) that accumulates in senile plaques continues to be highly controversial. Recently, using quantitative immunohistochemistry and computerized image analysis, we obtained evidence that at least a subset of early ("diffuse") senile plaques originate from neurons. In the current investigation, we employed monoclonal antibodies to A beta P and the same computerized methodology to examine in further detail the quantitative patterns of A beta P deposition in diffuse plaques in a population of intellectually intact elderly individuals. The presence of neurocentric concentration gradients of A beta P accumulation was confirmed in this study. Most significantly, this was the most predominant pattern of early amyloid deposition in the population studied. The highest concentration of A beta P was centered around neuronal cell bodies or their processes, and occasionally along neuronal plasma membranes. Computerized images showed patterns that can be interpreted as a pathogenetic sequence ranging from initial neurogenic concentration gradients centered around one single neuron to larger deposits (diffuse plaques) composed of several "anastomosing" gradients involving several adjacent neurons. It is proposed that the described very early deposits constitute the initial stage in the development of the senile plaque. Although this study does not fully prove that the accumulated A beta P is synthesized in the neuron or neuronal process it surrounds, the images herein presented suggest that neurons are the initial nidus of plaque formation.

Alzheimer Disease↗

PubMed2026

Analysis of deep learning techniques in computer-aided diagnosis for meniscus injuries: a systematic literature review.

Meniscus informatics is a growing subject of study in the healthcare industry. One of the major hindrances to the healthcare system's transformation is obtaining knowledge and meaningful information from complicated, high-dimensional and diverse sources. Modern biomedical research, for instance, has seen an increase in the use of complex, dissimilar, poorly documented, and generally unstructured electronic health records, imaging, sensor data and text, even after many current techniques have been used to extract more robust and useful elements from the data for analysis. New efficient standards for building end-to-end learning models from complex data are therefore needed. Therefore, the current study aims to examine the most recent research on the use of deep learning techniques for diagnosing meniscus tears and recommend creating comprehensive and meaningful interpretable structures that might benefit the healthcare industry. We also draw attention to shortcomings and the need for better technique development, and we provide new perspectives about this exciting new development in the field.

Humans↗

PubMedDate not supplied

X-ray solution scattering studies on vinblastine-induced polymers of microtubule protein: structural characterisation and effects of temperature.

We report here on X-ray solution scattering and electron microscopy studies of microtubule protein in the presence of the antimitotic drug, vinblastine. In buffer conditions used for microtubule assembly, vinblastine caused the formation of coil-like structures. The coils appeared to be made up of two protofilaments. Details of the structure and behaviour of coils in solution were obtained from interpretation of their solution scattering patterns. Upon increasing temperature from 4 to 37 degrees C the pitch of the coils increased from 25.92 to 26.96 nm. However, little change was observed in their mean diameters (38.46 and 38.45 nm, respectively). Increasing the temperature also favoured increased formation and/or elongation of the coils. The effect of temperature on the pitch was fully reversible. Vinblastine-induced assembly of pure tubulin also showed the formation of coils. However, these coils appeared to consist of only one protofilament. Their mean diameters (38.35 nm) were similar to those of the coils formed from microtubule protein.

Animals↗

PubMedDate not supplied

The Staphylococcus aureus alpha-toxin channel complex and the effect of Ca2+ ions on its interaction with lipid layers.

Using the techniques of two-dimensional crystallization on supported lipid bilayers together with computer image processing, two distinct two-dimensional crystal types of staphylococcal alpha-toxin complex are formed depending on the presence or absence of Ca2+ ions. Without Ca2+, these are hexagonally packed (in A, a = b = 89.5 +/- 2.5 A; theta = 119.7 degrees) With Ca2+ present, rectangular crystal packing is seen (in A, a = 114.8 +/- 1.6 A, b = 140.2 +/- 0.7 A; theta = 89.1 degrees). A third, banded crystal type is also seen which is interpreted as a side-to-side packing of regular tubules. We use these tubular crystals for cross-correlation searches with top and side-on views of the complex from single particle reconstructions, and with the repeating units from the two-dimensional crystal types. The results lead us to propose a model in which the different two-dimensional crystal types are formed as a result of alpha-toxin hexamers packing in different orientations. In the hexagonal crystals the hexamers lie end-on with a 6-fold axis in projection. On the addition of Ca2+, the hexamers reorient to lie tilted with respect to the support, thus giving rise to a rectangular projection.

Bacterial Toxins↗

PubMed1992

Reconstruction of the electrocardiogram during heart surgery.

Electrocardiograms (ECG) recorded during arrhythmia surgery are used for identification of arrhythmias of different morphology. However, the interpretation of an intraoperative ECG is difficult because some leads cannot be recorded and the signals of the remaining leads often differ from those of a preoperative recording because of the sternotomy. Therefore, a method for reconstruction of a complete intraoperative ECG, which resembles a preoperatively recorded ECG, was studied in 24 patients undergoing heart surgery. The reconstruction method involves calculating coefficients for a transformation matrix, using a preoperative ECG recording and a first intraoperative ECG recording. Once this matrix has been established, further intraoperative recordings can be transformed into an ECG which strongly resembles a preoperative ECG. The correlation between reconstructed intraoperative leads and the corresponding preoperative leads was high in the leads Vx and Vy (median correlation coefficient 0.98 and 0.97) and slightly smaller in lead Vz (0.94). Further studies will prove if the method can be useful in arrhythmia surgery.

Aged↗

PubMed1992

Polyaxonal amacrine cells of rabbit retina: PA2, PA3, and PA4 cells. Light and electron microscopic studies with a functional interpretation.

Polyaxonal (PA) amacrine cells are a new class of amacrine cell bearing one to six branching, axon-like processes that emerge from the cell body or dendritic trees within 50 microns of the cell body. These slender processes of uniform caliber branch at right angles and in many respects closely resemble the axons of Golgi type II cells found elsewhere in the brain. Of the four types of polyaxonal amacrine cell that we have recognized in rabbit retina, two have been described previously in brief communications. One of these, the PA1 amacrine cell with its interstitially displaced cell body, located in the inner plexiform layer (IPL), has been analyzed extensively in two preceding reports. This paper concerns PA2, PA3, and PA4 amacrine cells. Type 2 polyaxonal (PA2) amacrine cells, identified in Golgi preparations of whole-mounted rabbit retinas, have smaller cell bodies (9-14 microns) than the other three types and these are always displaced to the ganglion cell layer (GCL) or the inner border of the inner plexiform layer (IPL). The dendritic fields of PA2 cells are also smaller than those of other PA amacrine cells, and most of their sparse dendritic branching is narrowly stratified at the border of strata (S) 4 and 5. Some members of this more heterogeneous amacrine cell "type" are bistratified, however, and more highly branched with terminal branches rising to end in S1. PA2 amacrine cells bear a scattering of small dendritic spines and may also exhibit complex dendritic appendages arising at the ends of terminal branches in proximal regions of the dendritic tree. PA2 cells emit one to three axons from the proximal dendritic tree, and about half of the cells bear a single axon. Type 3 polyaxonal (PA3) amacrine cells resemble PA1 cells in the large size of their cells bodies (11-16 microns) and dendritic fields, but differ from the latter in placement of cell bodies, which is in the GCL, and dendritic and axonal stratification, which is multistratified, ranging from S4 to S1, with a concentration in S3 or S4 and a variable contribution to S1. PA3 cells differ from PA1 cells in several other respects, including dendritic branching which occurs at higher frequency and is biased toward temporal retina, and in characteristic bristling dendritic spines, clustered in the intermediate regions of the dendritic tree, that are longer, more variable in appearance and more tightly clustered than the small, uniform spines of PA1 cells that are clustered on proximal dendrites.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Ocular↗

PubMed1992

Oral diagnostic reporting and synchronized image filing using magneto-optical disks.

An experimental radiologic reporting system has been developed and tested. The rewritable and compact magneto-optical disk (MOD) is applied to storing medical images with oral diagnostic reports of these radiologic images. The disk is 5.25 inches in diameter, has 600 MB memory capacity, is erasable, light and compact. Advantages are simultaneous recording of radiologic images and their oral reports by radiologists, and application to circulation of media inside the hospital as well as to filing of medical images. The MOD has a multimedia function of communication and filing. When medical images are taken and stored, oral interpretation by radiologists can be simultaneously added. Physicians can get information of the images and their reports by oral speech at the same time in front of computer workstation. Furthermore, integration of a voice recognition capability is now being undertaken.

Image Processing, Computer-Assisted↗

PubMed1977

New approach to interpretation of technetium-99m pyrophosphate scintigraphy in detection of acute myocardial infarction: clinical assessment of diagnostic accuracy.

A modified classification for interpreting technetium-99m pyrophosphate scintigrams defines the 2+ diffuse pattern of tracer uptake as equlvocal rather than positive for acute myocardial infarction. Results of scintigraphy using this classification were compared with results of standard diagnostic tests for myocardial infarction in 235 patients admitted to a coronary care unit with acute chest pain. Of 81 patients with acute transmural infarction by standard clinical, electrocardiographic and serum enzyme criteria, 76 had a positive, 5 an equivocal and none a negative scintigram. Of 18 with acute nontransmural infarction by standard criteria, 7 had a positive, 9 an equivocal and 2 a negative scintigram. This it was uncommon for a patient with acute myocardial infarction, transmural or nontransmural, to have a definitely negative technetium-99m pyrophosphate study. Ten patients had equivocal evidence of infarction by standard criteria. Of the remaining 126 patients with no evidence of acute myocardial infarction by standard criteria, 87 had a negative, 35 an equivocal and 4 a definitely positive scintigram. Thus the definitely positive scintigraphic pattern was relatively highly specific for acute myocardial infarction. If the 2+ pattern had been considered positive, the specificity of the technique would have been greatly decreased. Computer processing strengthened observer certainty of the visual impression but changed the scintigraphic evaluation in only eight cases. Thus, use of an equivocal pattern renders technetium-99m pyrophosphate imaging both an extremely sensitive and specific method for detecting acute myocardial infarction.

Acute Disease↗

PubMed1992

Subperiosteal resorption: effect of full-frame image compression of hand radiographs on diagnostic accuracy.

Image compression is essential to handle a large volume of digital images, including computed tomographic, magnetic resonance, computed radiographic, and digitized images in a digital radiology operation. Developed during the past few years, full-frame bit allocation performed with the cosine transform technique has been proved to be an excellent irreversible image compression method. This article describes the effect, on the accuracy of diagnosis of subperiosteal resorption, of using the hardware compression module to produce hand radiographs. Receiver operating characteristic analysis of the interpretation of 71 radiographs by five observers demonstrated that there is no statistically significant difference in diagnostic accuracy between the original radiographs and compressed and reconstructed images obtained with a compression ratio as high as 20:1.

Bone Resorption↗