[Limits of conventional technics and possibilities of alternative methods in anthropometry. An example for the use of biophotogrammetry in the craniometric technic].
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Cephalometry↗
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[Temporal change of the disc in normal adults (author's transl)].
We have recently proposed a procedure called stereochronoscopy which allows the detection of temporal changes in the disc by stereoscopic observation of exactly centered fundus pictures. We show that this procedure can also be applied in a slightly modified form to fundus pictures that are not specially centered, although with less precision. Using this technique we were able to show on material covering 10 years (50 eyes) that the discs of healthy adults do not as a rule change over a period of at least 8 years. This is valid for observation of the pictures with an overall magnification of X 14.
Adult↗
[Meandering of retinal arteries from pulse wave: a stereochronoscopic study (author's transl)].
In a case of aortic insufficiency, increased snaking occured with very pulse wave coming through the retinal arteries. When photographs taken at diastolic and systolic culminations were compared, with the haploscope, when stereoscopically seen, they clearly showed the subtile deformation of the vessels under a stereoscopic effect.
Aortic Valve Insufficiency↗
Quantitative analysis of scoliotic deformity by Moiré method.
The quantitative analysis of back surface deformity produced by scoliosis was carried out by the moiré method. A new computerized semi-automatic apparatus to be used for the analysis was developed. Parameters which indicate scoliotic deformity were calculated. The relations between these parameters and X-ray findings were examined. It was found that the parameters well estimated the spinal condition and could be used for an automatic diagnosis of scoliosis. Then, the effect of the treatment of scoliosis was evaluated by this analytic method. It was indicated that the improvement of deformities by treatment was not always correlated with the change of the spine on X-ray film and moiré analysis was significant as a three-dimensional evaluation procedure.
Adolescent↗
[Double contrast magnification stereoradiography and three dimensional interpretation of the gastrointestinal tract (author's transl)].
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Digestive System↗
[Biomechanics and kinesiology].
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Adolescent↗
Breast cancer detection utilizing biostereometric analysis.
Twelve female patients participated in a study designed to employ computer-assisted biostereometric analysis for the detection of breast masses. All breast masses were previously documented by physical examination and followed by xeromammography, stereophotography, and histopathologic confirmation of tumor type. "Contour mammograms" were produced from the biostereometric photographs. These data were analyzed first for tumor detection and location by visual inspection. A second analysis employed a computed algorithm designed to locate and measure surface aberrations that suggest the possibility of underlying breast tumor. Visual analysis yielded the exact location of breast tumors in eight of the ten malignancies; computer analysis exactly located nine of the ten malignancies. In the computer analysis, one malignancy not exactly located by quadrant was, nevertheless, located in the correct breast. The results of the study suggest that the biostereometric process may have future use in screening or prescreening procedures for breast cancer detection. It is noninvasive, applicable to large numbers of women and with suitable refinements, and capable of being fully automated.
Aged↗
Simultaneous stereoscopic fundus camera incorporating a single optical axis.
The method of stereoscopic fundus photography, where both photographs are taken simultaneously, yields the most consistent and reproducible record of depths in the fundus. However, all systems devised to date have had undesirable photographic aberrations. For the most part, this has resulted because the optical axis of each image is not the same as that of the objective lens. A single-axis system has now been devised to minimize distortions in the stereoscopic photographs, which therefore makes stereophotogrammetry relatively simple. This design also has other advantages such as simplified alignment procedures, the use of Barlow lenses for multiple magnifications, and various paired apertures for obtaining photographs especially adapted to unusual situations.
Fundus Oculi↗
Stereophotogrammetry marking and serializing: a simple technique.
A relatively simple, inexpensive, and yet exact, binary code data-back-fiducial marking system may be added to any existing camera by the use of LED illumination of the back of the film through precisely aligned holes in the focal plane pressure plate.
Data Display↗
Stereology--or how figures for spatial shape and content are obtained by observation of structures in sections.
Stereology is a geometrically and statistically defined body of simple methods for estimating morphological quantities of three-dimensional (3-d) structures from measurements made on two-dimensional (2-d) sections. The straightforwardness and the strength of its theoretical basis is illustrated by some newer methods applied in experimental clinical research. Contrary to expectation, the reduction in information from 3-d structures to 2-d sections brings about only a minor increase in the statistical uncertainty of the central moments of most of the fundamental structural characteristics. The sole exceptions are the number of isolated structures and the degree of connectedness in 3-d space, structural quantities the importance of which is limited to the questions of (neo)genesis and communications, respectively. In general, the overall variation in morphometry is determined more by biological than methodological variation. Therefore, stereology is part of the broad spectrum of modern quantitation techniques the sensible application of which depends primarily on common sense in the experimental technique and in the definition of the biological question. The ease and the simplicity of the measurements contrasted by the still quite elaborate and difficult histological preparations of tissue mean that the automation of the measuring process alone is not sensible.
Animals↗
Prediction of artificial anterior chamber depth.
Seventy-six patients undergoing cataract extraction and intraocular lens implantation were examined prospectively to evaluate the accuracy of a photogrammetric method for estimating postoperative anterior chamber depth and the predictive value of preoperative anterior chamber depth on postoperative anterior chamber depth. The photogrammetric method was less accurate than the use of a fixed figure determined by the average measured postoperative anterior chamber depth. Measuring the anterior chamber depth preoperatively had even less predictive value.
Anterior Chamber↗
[Photographic moiré method for preliminary diagnosis of spine deformity (author's transl)].
Moiré topography is a biostereometric method which produces a three-dimensional image of the shape of the trunk. In structure scoliosis an asymmetry of the two halves of the back is seen. This method has been studied and the range of the asymmetry of the moiré pattern has been compared with clinical observations and X-ray findings in case with structural scoliosis. Because of the sensitivity of the moiré method an asymmetry of at least half fringe interval could be regarded as a positive result. All the observed asymmetries less than one fringe interval had a lateral deviation of the spine of less than 10 degrees according to Cobb when W-ray examined. The moiré method seems to be very suitable for the screening of structural scoliosis, owing to: 1) its ability to detect and document even small deformities by photography; 2) the simplicity of the technique; 3) the possibility of documenting the condition of the back for comparison with subsequent examinations; 4) non-invasive for the patient.
Humans↗
[A palatographic-photographic study of consonant pronunciation in Afrikaans].
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Humans↗
Measurement of polyethylene wear in metal-backed acetabular cups. I. Three-dimensional technique.
A new technique, the 3-dimensional technique, has been developed. Using a digitzer, points taken from anteroposterior and lateral radiographs are input into a personal computer. A 3-dimensional solid model of the prosthesis is created using custom software. Tilt and anteversion of the acetabular cup are measured, and the model is rotated to a standard frontal view, allowing measurement of femoral head displacement from the center of the acetabular cup. Comparing serial radiographs of the same patient gives the direction and distance of femoral head displacement over time, and this value is used to calculate the minimum volume of polyethylene debris generated. The 3-dimensional technique has been validated by construction of a precision acrylic phantom, and milling of a metal-backed acetabular cup to simulate polyethylene wear. Three-dimensional measurement of femoral head displacement using this technique has an accuracy of +/- 0.15 mm, and volume calculations are within 8% of the true amount of polyethylene removed from the cup. The 3-dimensional technique gives previously unavailable information, and can be used for clinical evaluation of polyethylene wear and evaluation of new prosthetic designs and bearing surfaces.
Acetabulum↗
Measurement of polyethylene wear in metal-backed acetabular cups. II. Clinical application.
The new 3-dimensional technique was applied to the radiographs of 141 patients who had received Porous Coated Anatomic total hip prostheses. Values were obtained for the position of the acetabular cup, the 3-dimensional distance and direction of femoral head displacement, and the minimum volume of polyethylene debris produced. Mean age of the patients at the time of replacement was 61 years old; mean followup was 5.6 years (range, 4-7.2 years). Change in the position of the femoral head between initial and long-term followup films was assumed to represent polyethylene wear, and formulas were used to calculate the minimal volume of polyethylene debris produced. The overall rate of 3-dimensional femoral head displacement was 0.264 mm per year, almost twice that usually quoted in the current literature for 2-dimensional linear wear. A significant contribution to this value was made by anterior and posterior displacement. Two-dimensional femoral head displacement (measured in the plane of anteroposterior radiographs) on the same patients was 0.149 mm per year. The mean minimum volume of polyethylene debris produced after 5.6 years was 0.448 cm3 (range, 0.00-2.83 cm3), giving a mean rate of 0.079 cm3 polyethylene debris produced each year. Thirteen patients in this series had radiologic osteolysis and a significantly greater femoral head displacement and polyethylene volumetric wear than those with no osteolysis. Patients with a 32-mm femoral head diameter and a polyethylene linear < 1 cm thick had a significantly greater amount of polyethylene wear. This series gives previously unavailable data on 3-dimensional femoral head displacement and is the first report that correlates the minimum volume of polyethylene wear produced with radiologic osteolysis.
Acetabulum↗
[Person identification with video super-projection].
The author reports on the identification of a male corpse which was found in a marsh where it had been lying for approximately three months. Autopsy revealed a laceration of the scalp with an underlying skull fracture. Since the corpse could not be identified by means of dental status, bloodgrouping or finger prints, the method of videosuperimposition was used. A comparison of the skull with a photograph of the suspected victim confirmed identity.
Adult↗
A simple and accurate method for 3-D measurements in microcorrosion casts illustrated with tumour vascularization.
Microvascular corrosion casting is an established method to investigate vascular patterns of nearly all organs. Trying to evaluate these specimens quantitatively using native scanning electron microscope (SEM) pictures always implied a big error, because the information of depth cannot be taken into account. However, SEM stereo pairs allow for exact measurements. Tumour microcorrosion casts were used to demonstrate the feasibility of this 3-D quantification method. The information of depth was calculated for each measuring point using the parallax. From the resulting coordinates the intervascular distances, the interbranching distances as well as the interbranching angles were determined. We found significant differences between all investigated tumours. Reproducibility tests and tests for the greatest error possibilities resulted in a maximum deviation of 2.5% to be expected. Consequently this method is suitable for all application ranges of microvascular corrosion casting as a quantitative determination method.
Animals↗
Computerized morphometric analysis of the femoral diaphyseal canal.
The constant increase in the use of hip arthroplasty and the continuous search for the best possible adaptation of the implant to femoral anatomy have led to the development of methods of radiographic analysis that are increasingly precise and reliable. Among these the methods that include the use of traditional radiograms-despite their limits-deserve a place of importance. In fact, these methods offer the advantage of being easy to apply and of allowing for a comparison to be made with pre-existing files. Computer science is useful in this field, in particular, computerized analysis, both morphometric and statistical, of the data acquired by digitizer. The protocol of acquisition and analysis that we applied to x-rays in anteroposterior view allowed for an evaluation to be made of some of the morphologic parameters of 354 femurs (corresponding to 264 patients), relating them with the pathologies that led to hip arthroplasty. The duration of a cementless hip prosthesis strongly depends on primary stability. For this reason, an ever-increasing number of studies tends to make a precise evaluation of the morphology of the joint, in order to obtain excellent contact between bone and prosthetic component. The methods used are essentially radiological, with the use of computerized tomography and stereophotogrammetry. Morphometric studies of the proximal femoral area have in particular considered the width of the medullary canal at various levels; the cervico-diaphyseal angle; the flare index of the femoral canal (relationship between the internal metadiaphyseal diameter and that of the isthmus) and the distance between the rotation center of the femoral head and the diaphyseal axis. The evident absence of proportion between femoral sizes and shape of the medullary canal has led to the search for parameters capable of describing in simple fashion the shape of the femoral diaphyseal canal. A good describer of femoral morphology is the flare index, that allows for classification of the various shapes of the diaphyseal canal in three families: "stove-pipe like", "normal", "champagne glass like". The distinction between these groups is not clear, as the passage from one shape to another is gradual. The idea of obtaining more knowledge on femoral morphology, also to the purpose of determining possible new criteria that may be of help in preoperative planning and in the choice of a model to be implanted, has suggested our study on modifications caused by some of the pathologies that most frequently lead to arthroplasty.
Adult↗