Biomedical subjects

G Witte

Publications and source records attributed to G Witte.

24 records · Page 2Linked to original sources

PubMed1987

The use of the Fourier transform in cardiac digital angiography.

Digital angiography has achieved broad clinical application as a morphological imaging modality through the technique of temporal subtraction known as digital subtraction angiography (DSA). After applying the Fourier transform to the intensity time curves (ITC) of an angiographic sequence, we are able to produce both morphological and functional images. The resulting pictures show an improved signal-to-noise ratio, reduction of motion artifacts, easy application of phase-synchronous subtraction, and integration and quantitative visualization of blood flow. The methods are demonstrated with nonselective angiograms and intravenous levocardiograms. Furthermore, when applied to angiographic sequences, the Fourier transform leads to a significant reduction in data without loss of important information.

Angiography↗

PubMed1987

[Functional imaging of blood flow velocity amd myocardial perfusion using the Fourier transform parameter].

In the past, the radiology of the cardiovascular system has consisted of angiographic investigations which only demonstrate morphology. The introduction of digital techniques into radiology has made possible the demonstration of pure morphology and beyond that, calculations which provide functional information. We demonstrate functional images which, by using Fourier transformations, provide information on blood flow and organ perfusion. In this way, it is possible to obtain important additional diagnostic information concerning the cardiovascular system, without imposing any further stress on the patient.

Blood Flow Velocity↗

PubMed1986

[Imaging of ventricular wall motion using venous DSA. A new method in radiologic cardiac diagnosis].

Until now, angiographical and nuclear medicine examination techniques for imaging left ventricular wall motion have been presenting with difficulties endemic to the methods themselves. For the first time in cardiological diagnostics, digital subtraction angiography (DSA) makes it possible to perform a fairly non-invasive examination with good spatial and temporal resolution. Functional analytic evaluation, however, still demands time-consuming, complicated post-processing. In this article we introduce a method that uses an additive window technique for the immediate generation of wall motion images.

Angiography↗

PubMed1986

[3-dimensional display of computed tomographic studies of craniofacial anomalies].

Craniofacial anomalies are conventionally investigated by cephalometry using ordinary radiographs and by computed tomography. Both methods have the major disadvantage of trying to demonstrate a complex three-dimensional structure, such as the skull, in two dimensions and they therefore cannot display a true spatial image. We present the principle underlying a three-dimensional display derived from computer tomographic studies and discuss the clinical application in the diagnosis of craniofacial anomalies.

Adolescent↗

PubMed1986

[Rotator cuff ruptures of the shoulder joint. Sonography--arthrography].

47 patients suspected of rupture of the rotator cuff were sonographed and arthrographed. Rupture of the rotator cuff was diagnosed in 12 cases, both diagnostic methods yielding the same result. In 29 patients sonography and arthrography did not reveal any abnormal findings. Six ruptures evident in sonography were not confirmed by arthrography and were considered false positive. Direct pointers towards rupture of the cuff would be: echoless defects, cuff cannot be visualised fully or in part, irregularities of movement during dynamic examination. Echoless "cystic" areas in the periarticular soft parts must be considered an indirect pointer. Echorich focal findings in the echopoor cuff represent a differential diagnostic problem and we cannot give a final assessment as yet. Shoulder sonography is justified as a screening method in suspicion of rotator cuff rupture before initiating arthrography. If sonography reveals no abnormal findings, shoulder arthrography need not be performed.

Arthrography↗

PubMed1985

[Applicability of digital methods in x-ray diagnosis].

The significance of digital examination methods continues to grow. Since the introduction of computer tomography, two additional digital imaging modalities-digital subtraction angiography (DSA) and magnetic resonance imaging (MRI)--have been developed. In this paper we present basic techniques of computerized image processing and outline foreseeable future developments. Furthermore, we discuss the possibilities and problems presented by digital picture archiving and communication systems (PACS).

Analog-Digital Conversion↗