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At least 1,297 records · Page 72Linked to original sources
PubMed1985

[Initial experiences with a new stereo roentgen technic in general radiology].

A new stereo X-ray technic, which is simple, easy to handle, universally applicable and without intrinsic disadvantages for the patient, is demonstrated. The two attributes of stereo X-ray, exact spatial representation of the relationship between structures and the addition of the two stereo pictures to give better signal/noise ratio are explained. The efficiency of this method is presented with investigations of the G.I. tract, abdominal angiography and the knee arthrography.

Digestive System↗
PubMedDate not supplied

Generation of three dimensional images from CT scans: technological perspective.

Routine production of three dimensional (3-D) surface images from CT scans for clinical applications has been performed in 700 cases. These images have been found useful in craniofacial, orthopedic, and neurosurgical applications. Three dimensional images may be produced on the same CT scanner that collected the original slices. The emergence of 3-D imaging as a routine radiological procedure involves special technological requirements to avoid artifacts and to produce a useful result. Three dimensional surface reconstruction procedures are reviewed and examples of clinical application are presented.

Adult↗
PubMed1985

Stereochronometry: quantitative measurement of optic disc cup changes.

The authors have developed an objective, quantitative method for detecting optic disc cup changes that occur with time. Called stereochronometry, this new technique uses a stereoplotter to measure changes recorded in the combination of two single photographs taken of the same optic disc at different times. The reproducibility and sensitivity of stereochronometry were evaluated using a model eye. Stereochronometric measurements were significantly correlated with calibrated changes of depth and width of the cup of the model eye. Standard deviations for five measurements of cup changes without camera shift range from 2 microns to 18 microns, and errors (deviations of the mean of measurements from calibrated cup changes) ranged from -26 microns to +33 microns. Standard deviations and errors in the measurement of cup depth and width were significantly increased when the camera was shifted by 2.5 mm between photographs to simulate possible changes in photographic conditions.

Fundus Oculi↗
PubMed1985

Subsidence of the femoral prosthesis. A stereophotogrammetric evaluation.

A quantitative three-dimensional measurement method, radiographic stereophotogrammetry (SPG), was employed to assess the relation between early subsidence of the femoral prosthesis after total hip arthroplasty (THA) and subsequent clinical course. The SPG technique and the authors' error control mechanisms are described in 15 patients in the early postoperative period, and the findings are correlated with those of follow-up clinical examinations. Among the 12 patients who remained clinically asymptomatic with respect to pain, only one had an SPG estimate of subsidence in excess of 1 mm at any point in time. Each of the three patients who later became symptomatic had SPG estimates of subsidence in excess of 1.75 mm within six months of the operation. Thus far, the patient with the largest estimate of subsidence is the only one who required surgical revision.

Evaluation Studies as Topic↗
PubMed1985

Computer analysis of the optic cup in glaucoma.

This paper describes two complementary methods for computer analysis of the optic disc in glaucoma. The objective of both techniques is to detect and monitor changes in the optic disc through the use of digital image processing techniques that allow user intervention. In the first method, optic disc photographs from successive years are digitized, scaled and registered (aligned) with each other, and are then displayed in rapid sequence on a television monitor. Changes in the optic cup thus appear as localized movement on the display, while stable regions of the optic cup appear stationary. Both monocular and stereo photographs can be processed by this technique. In the second method, stereo optic disc photographs are digitized and processed by a new, robust, photogrammetric computer algorithm that quantifies optic cup depth information. Together, these two techniques may be valuable for both clinical and research purposes in the detection and monitoring of glaucomatous optic cupping.

Computers↗
PubMedDate not supplied

Moiré topography in the care of foot deformities.

Podoscopic images and moiré images combined are useful for comparing the foot under weight-bearing and non-weight-bearing conditions. This makes it possible to evaluate the effect of weightbearing on the bone structures of the foot and is valuable in the treatment of foot deformities.

Body Weight↗
PubMed1979

Caloric and exercise requirements of space flight: biostereometric results from skylab.

The biostereometric study of the Skylab astronauts used stereophotogrammetry to make accurate three-dimensional measurement of body form, from which regional and total body volumes were derived. Volume changes in the thighs and calves, over the course of the flight, showed a high correlation with inflight exercise on the bicycle ergometer, and suggested that an exercise level of 80-100 W-min/d/kg lean body mass would be necessary to prevent inflight muscle atrophy. The bicycle ergometer is thus a relatively inefficient means of preventing leg muscle atrophy. Inflight caloric intake showed a high correlation with the change in volume of the buttocks, the abdomen, and the body as a whole, and suggested that a caloric intake of 47-51 kcal/d/kg lean body mass would be necessary to prevent a change in body fat. Only one of the astronauts exceeded this range and gained body fat; the group as a whole showed a mean fat loss of 1.2 kg.

Adult↗
PubMed1974

[The use of stereologic image analysis in medicine (peripheral nerves)].

The use of image plane scanning for the purpose of quantification of data is becoming increasingly important in medicine and biology. Such equipment allows complex geometric-statistical relationships to be investigated by reduction to a counting process in which picture elements are counted (using a photocell), stored, and evaluated. Various absolute values of interest can then be computed using certain mathematical relationships. These methods, using automatically controlled sampling, are fast, and, since they are able to detect small variations in light intensity, very accurate. Furthermore, even in the presence of highly complex patterns, an accurate surface area measurement can be made. Peripheral nerve cells, for example, lend themselves well to such methods, since the strong contrast between individual structural elements provides excellent conditions for automatic measurement.

Axons↗