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PubMed1978

Image processing in pathology.

The present study is an effort to ally biopsies to well defined groups of diseases by means of automatic analysis of liver cell nuclei. The results obtained should support the morphologic differential diagnosis of liver diseases. A total of 78 liver biopsies from patients with obstructive jaundice, chronic hepatitis, acute viral hepatitis or with alcoholic liver injury were investigated. Performing automatic analysis of the microscopic pictures 95% of the equatorial sectioned liver cell nuclei are correctly recognized.

Cell Nucleus↗
PubMed1976

Minicomputer enhancement of scintillation camera images using fast Fourier transform techniques.

Minicomputer methods were developed to enhance lesions in scintillation camera images. This study was directed towards improving the diagnostic quality of liver images. A PDP-12 digital computer was interfaced to a Pho/Gamma HP III scintillation camera and programmed to carry out two-dimensional frequency-domain analysis and processing as an on-line operation. A two-dimensional frequency spectrum is produced. An interactive program allows the operator to construct graphically a frequency-domain filter and apply it to the data matrix. The filter is optimized using the image of a known phantom and then applied unchanged to the clincial liver image. An inverse Fourier transform produces an enhances image in the spatial domain. Significant enhancement of both phantom and liver images has been obtained.

Diagnosis, Computer-Assisted↗
PubMed1975

Scintillation camera studies of isotope flow in arteriovenous malformations.

A significant proportion of arteriovenous malformations are still undetected on conventional brain scans. Dynamic scintillation camera studies have shown a pronounced and rapid isotope accumulation in these structures. By means of data processed flow studies, one can distinctly select the inflow phase etc., display TV pictures in optimal phase, and make quantitative comparisons. Thereby, one can obtain a very probable diagnosis, even when the AVM is small or has the characteristics of a fistula which is not seen on routine scans. As the method is simple and not time consuming, it is well suited for clinical screening.

Aged↗
PubMed1977

Experimental infarct sizing using computer processing and a three-dimensional model.

A method for noninvasive sizing of myocardial infarction, in which data from technetium-99m stannous pyrophosphate scintigrams and a three-dimensional model were used, was tested on experimental, acute anterior infarcts in dogs. The results indicate that the method does size experimental anterior infarcts accurately, but further testing will be necessary to assess the capabilities of the technique for sizing other types of infarcts.

Animals↗
PubMed1992

A discussion of two wavefront aberration correction procedures.

This review paper discusses the basic properties of two adaptive signal processing procedures for dealing with weak scattering in a phased array transducer system. A fundamental improvement in the lateral resolution of ultrasonic echo scanners will result if the weight vector of a large phased array transducer can be modified to account for distortion in the propagation medium. Lateral resolution in most tissue is limited to a few mm by wavefront-distortion-induced sound-speed variations. One important wavefront-distortion source is scattering from local speed variations within large and reasonably homogeneous tissue beds such as the liver. Scattering disperses some energy from the beam and perturbs the wavefront, thereby distorting the image and limiting the resolution to the scale of the distortion. Often, such scattering is weak, meaning that most of the energy in the beam is unscattered. The total field at the receiving transducer is the vector sum of the unscattered and scattered fields. In weak scattering the unscattered field is dominant and the resultant field can be treated as the unscattered field plus a perturbation. The net effect is primarily a distorted phasefront, while the amplitude or modulus of the wavefront remains reasonably intact. Refraction and strong scattering effect the wavefront more severely and are less responsive to these algorithms.

Algorithms↗
PubMed1977

An automated method of differential red blood cell classification with application to the diagnosis of anemia.

A method of automated red cell analysis suitable for the rapid classification of large numbers of red cells from individual blood specimens has been developed, and preliminarily tested on normal bloods and clinically proven cases of anemias and red cell disorders. According to this method digital image processing techniques provide several features relating to shape and internal central pallor configurations of red cells. These features are used with a fully automated decision logic to rapidly provide a quantitative "red cell differential" analysis, a report of the percentage subpopulations of recognized categories of red cells. For each subpopulation, measurements of mean cell area, mean cell hemoglobin content and mean cell hemoglobin density are provided. The nine types of red cell disorders studied with this method were: (a) iron deficiency anemia, (b) the anemia of chronic disease, (c) beta-thalassemia trait, (d) sickle cell anemia, (e) hemoglobin C disease, (f) intravascular hemolysis, (g) hereditary elliptocytosis, (h) hereditary spherocytosis, and (i) megaloblastic anemia due to folic acid deficiency. Preliminary indications are that the red cell differential is useful in distinguishing between these conditions.

Anemia↗
PubMedDate not supplied

Event-related potentials in a guessing task: the gleam in the eye effect.

Event-related potentials (ERPs) were recorded from a single subject performing a forced-choice guessing task. On each trial, ERPs were elicited by four, sequential, graphic images; 2 1/2 seconds after the last stimulus was delivered, the subject guessed which of the four images was experimentally (randomly) designated as the target. P200 had greater amplitude over the posterior scalp for stimuli which were guessed by the subject to be targets than for not-guessed stimuli. The amplitude of the P100, N100, and P300 components was unrelated to the subject's guess. A positive displacement evident in the waveforms from about 150-500 ms post-stimulus onset suggested that Slow Wave may have been partially responsible for the observed differences. These results suggest that ERPs may contain predictive information about a subject's subsequent responses in forced-choice guessing tasks. We termed this the "gleam in the eye" effect.

Arousal↗
PubMed1992

Our experience in the diagnosis of intraocular tumours by a B-scan computerized system and angiodynography (Doppler). Preliminary results.

The authors compare the ultrasound diagnostic results of intraocular tumours by A/B-scans (Sonomed B 3000, Sonocare, Sonovision STT-100) with images obtained using computerized B-scan (Sonocare, Sonovision STT-100, Acoustic Tissue Typing ATT) and angiodynopgraphy systems (Quantum Philips). The Sonovision uses a computerized ultrasound spectrum analysis to assess the probability that a given lesion is a certain tumour, rather than another. The ATT system provides diagnostic probability for type B and type E melanoma, for haemangioma and metastatic carcinoma. The Quantum ultrasound equipment was developed for studying the heart and the major blood vessels. It is a colour Doppler that simplifies the Doppler technique, allowing it to study small anatomical parts such as tumour-like lesions of the eye. The Doppler technique ascertains the presence and the velocity of blood flow in the tumours. In presenting the preliminary results with the new techniques the authors are aware that the ATT system is not designed for some of the lesions under study (melanomas after conservative radiotherapy).

Blood Flow Velocity↗
PubMed1992

Digital indocyanine green videoangiography and choroidal neovascularization.

This report describes a new system for digital indocyanine green videoangiography (ICGV) that provides enhanced imaging of the choroidal circulation. This newly assembled system was used to study a consecutive series of 129 patients with exudative age-related macular degeneration (AMD), and ill-defined or occult choroidal neovascularization (CNV). Overall, 39% of the patients in this study with occult CNV could be reclassified as having well-delineated or so-called classic CNV by virtue of the additional findings provided by ICGV. In this series, ICGV was particularly useful in identifying occult CNV in eyes with a large, serous pigment epithelial detachment (PED) and in eyes with recurrent CNV after previous laser photocoagulation treatment. Some of these patients were selected for laser photocoagulation of the abnormal choroidal vessels in order to evaluate the feasibility of this form of treatment on the basis of combined clinical, fluorescein angiographic, and ICGV findings. The results of this study suggest that ICGV is an important adjunct in the evaluation, classification, and laser treatment of patients with occult CNV secondary to AMD.

Aged↗
PubMed1992

[Electroencephalographic findings in dementia diseases].

Even if generally the EEG cannot yield specific pointers that are typical for a special pattern of dementia, it is nevertheless meaningful and helpful to perform routine EEG in demented patients. EEG is the functional additional examination that does not place any stress on the patient and is easy to perform at a low cost (1). As a functional diagram the EEG reflects the electrical processes taking place in the cerebral cortex, yielding an excellent image of the cerebral functional state. Assessment of the EEG is done in accordance with internationally standardised criteria. Particular attention is directed at a slowing-down of the background activity, the occurrence and extent of scattered theta and delta waves, their topographical distribution and the development of pathological EEG characteristics during recording (44). Update spectral analysis EEG procedures, i.g. the possibility to calculate power spectra for the individual EEG frequency bands and their topographic distribution, it may be possible in the near future to further improve differentiation between normal and pathological EEG findings. The functional dynamic aspect of the EEG is its particularly strong point in the differential diagnostic clarification of dementia patterns. By repeated EEG recordings, i.e. by close follow-up, and by relating the electrophysiological findings to the clinical pattern, reliable pointers are obtained for the extent of the activity of the process underlying the dementia pattern. EEG is predestined like no other method to enable early detection of rapid changes in cerebral function thanks to its easy operation and unlimited repeatability. The occurrence of parenrhythmic theta and delta waves in the EEG reflects in a special manner the acuity of an organic basic process. In this way EEG enables differentiation between acute and chronic processes of cerebral damage. Over and above this, correlation with the relevant clinical findings makes it possible to differentiate between reversible states of dementia and irreversible defect syndromes and hence also to point to the long-term outcome. Finally, the occurrence of certain patterns of findings or the identification of characteristic wave forms allows essential differential diagnostic pointers and definitions.

Aged↗
PubMed1977

Fully automatic computer-assisted pancreas imaging.

Good pancreas imaging is difficult to achieve even if a computer is applied. The special computer program proposed here was developed to optimize the results and to minimize the operator interaction with the data processing system.

Computers↗
PubMed1977

The role of the digital computer in pediatric cardiology.

A digital computer system is described which allows the real-time processing of all physiological signals obtained during a heart catheterization procedure and which makes all relevant results and informations available immediately during the investigation. In addition, special electronic units and programs have been developed in our institution for the automated extraction of morphological criteria from biplane angiocardiograms. Thereby right and left ventricular volume, shape and contraction pattern can be quantitated and used to characterize the performance of the heart as muscle and pump in physical terms. Recently, complete digital processing of videoangiocardiograms has been achieved in a stroboscopic mode, each videofield in real time. Application of image enhancement, subtraction, integration and restoration techniques leads to a fundamentally improved angiocardiographic image quality for a given amount of injected contrast material. Based on eight years of experience with digital computer application in pediatric cardiology, computer technologies are considered likely to become the method of choice in the future.

Angiocardiography↗
PubMed1992

Review of neural network applications in medical imaging and signal processing.

The current applications of neural networks to in vivo medical imaging and signal processing are reviewed. As is evident from the literature neural networks have already been used for a wide variety of tasks within medicine. As this trend is expected to continue this review contains a description of recent studies to provide an appreciation of the problems associated with implementing neural networks for medical imaging and signal processing.

Diagnostic Imaging↗
PubMedDate not supplied

133Xe regional lung perfusion and ventilation study with the computer-assisted gamma-camera.

A new method of studying regional lung functions using 133Xe and the computer-assisted scintillation camera is described. The method and the computer processing give details of the distribution of 133Xe during perfusion and ventilation and also measures of lung function. Some cases are described in detail, and the clinical significance of the method was confirmed in 45 cases.

Adult↗
PubMed1979

A general purpose computerized display and analysis system for image processing in nuclear medicine.

In this work a general purpose image processor is described, which takes into account the special features and the various requirements for analysing images in nuclear medicine. A new approach for system structure involving encoding and representing medical images is given. This encoder, which is part of the image processor, is efficient especially for long-term storage and for certain pattern recognition in medical imaging. In this processor a statistical package is incorporated for collecting medical statistics using the acquired patient data. This information is used together with the encoder for an automated diagnostic system.

Computers↗
PubMed1975

Quantitative colour-ultrasonography by means of a computer aided simultaneous tomogram.

In this newly developed method, the ultrasonic diagnosis has become quantitative. The data will remain quantitative so far as an image storage tube is used. With the conventional storage type CRT, it is impossible to memorize the reflected echo signals of different strength levels. But with our method, it becomes possible to memorize the images according to individual levels. By the direct digitalization of the ultrasonic echo images, more information is obtained from the reflected echo signals. By processing the original information with a computer, more accurate diagnosis is possible. It is hoped and believed, that this computer aided ultrasonic examination, with single scan display in colour or black and white, will further promote ultrasonic diagnosis in future.

Color↗
PubMed1975

Monitoring of patients with head injuries.

A practical protocol for evaluating and monitoring head injured patients has been presented. It has been stressed that monitoring is an ongoing process which begins with the initial evaluation and continues throughout the patient's hospital stay. The level of monitoring and thus the parameters to be monitored are determined on an individualized basis according to the patient's clinical status and his level of stupor and coma. It has been suggested that for mild head injuries, adequate monitoring includes periodic evaluation of the neurological status and vital signs; but the more severely injured patients require extensive and frequent monitoring of a large number of clinical and physiological parameters. Among the many parameters, the continuous monitoring of ICP and the respiratory system are perhaps the most useful indicators of the patient's condition. Several methods for continuous ICP monitoring which are readily adaptable to most neurosurgical practices have been discussed. These include the intraventricular catheter, subarachnoid screw, and the closed Rickham reservoir connected to a ventricular catheter. In our institution, the Rickham reservoir has been used to monitor ICP and at the time of this report, satisfactory ICP recordings have been obtained in 27 of 30 head injury patients. Although this method requires a small surgical procedure, we believe that the decreased incidence of infection, the rapid access to ventricular fluid, and its potential for long term monitoring justify its use. Suggestions for monitoring other physiological parameters have also been presented. Particular emphasis has been placed on the management of infants and children with head injuries. The clinical entity of chronic subdural hematoma in infants and children has been used to illustrate the value of ICP monitoring as a guide to further treatment. Finally, we have briefly discussed the place of computers in day to day patient care, research, and monitoring.

Blood Pressure↗