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Biomedical subjects

U Obermöller

Publications and source records attributed to U Obermöller.

3 recordsLinked to original sources

Digital venous subtraction angiography of pulmonary embolism in dogs.

Digital venous subtraction angiography makes it possible to obtain satisfactory images of the pulmonary vessels and thus to evaluate changes in the segmental and subsegmental arteries caused by pulmonary embolism. Morphologic as well as functional images can be produced in the course of a single examination. Semi-quantitative information about the vessels under examination as compared with the corresponding contralateral vessels is thus achieved. This procedure is valuable both in primary diagnosis and in subsequent repeat examinations after treatment.

Angiography

Data compression in digital angiography using the Fourier transform.

While digital techniques in radiology develop rapidly, problems arise with archival storage and communication of image data. This paper reports on experiments concerning data reduction of digital image sequences of the heart and the brain. The time-intensity curves corresponding to every picture element are subjected to the Fourier transform and reconstructed from a number of coefficients smaller than the original number of images. The reconstruction error is assessed by visual inspection and by determining the mean-square deviation of the original and the reconstructed curve. It is shown that compression factors between 5 and 10 may be achieved without loss of diagnostic information. It is furthermore demonstrated that storage of the images in the form of Fourier coefficients leads to advantages in fast retrieval, enhancement of morphology, and possibility of further quantitative analysis.

Cerebral Angiography