Biomedical subjects
Publications and source records attributed to W Kaiser.
Initial systematic examinations of the heart by ECG-triggered NMR are reported. Twenty-three abnormal findings were observed amongst 46 patients examined. Special indications are the search for cardiac aneurysms, intracardiac thrombi and changes from pressure and volume stress.
Absorption spectra and light-induced absorbance changes of crystals from Rhodopseudomonas viridis reaction centers are recorded. A theoretical analysis of the absorption and circular dichroism spectra is presented, yielding a consistent picture of spectroscopic and structural information.
MRI permits to study the anatomical structures of the heart and great vessels without cardiac catheterization or contrast injections. It aims to differentiate trachea and bronchia from the mediastinal lymph nodes. In mediastinal tumours, MRI supplies essential information for the planning of therapy. Only in the area of the structures adjacent to the diaphragm, an improvement of the images by means of additional respiratory gating is desirable.
MRI allows non invasive detection and diagnosis of benign and malignant diseases of the breast. This study, using solenoid surface coils, indicates, in a limited experience, the advantages and disadvantages which this new approach is expected to afford.
Overview on informations which are necessary to interpret MRI and MRS. The approach is related rather to application than it is a physical one. The central steps in comprehending MR are presented, e.g. frequency decomposition in order to obtain local information with MRI or chemical information with MRS, the spin echo in order to differentiate instrumental dephasation from dephasation by molecular interference, perfusion in MRI, and the components of sensitivity in measuring different nuclei etc. The report terminology is based on the description of grey scale pictures, but one has to consider that the information is not one-dimensional but multiparametric. Therefore new terms have to be developed, a problem similar to that of describing scintigraphic time sequences in nuclear medicine.
A new method of processing SPECT of 201T1 myocardial images is demonstrated based on the idea that 3-dimensional myocardium might be a curved area which can be presented in an unfolded form as a single planar image. An example of the procedure including parametric pictures is demonstrated.
Thallium-201 single photon emission computed tomography (SPECT) is a new method for the scintigraphic visualization of the left ventricular myocardium. With SPECT a three-dimensional imaging by computerized slicing of the myocardium in various axes is possible. To investigate the capabilities of this new imaging technique, detection and quantification of remote transmural infarctions were compared with ventriculographic, coronarographic and electrocardiographic findings. 31 of 80 investigated patients had had a prior myocardial infarction. The left ventricular myocardium was divided into 7 regions in the scintigraphic as well as in the angiographic studies. In a total of 560 segments the sensitivity of SPECT for infarct detection was 87.5% with a specificity of 99.8%. Infarcts which were not detected scintigraphically were relatively small (mean 13.5% of the circumference). To quantify the infarct, the size of the defect was determined scintigraphically from a sagittal long axis and two short axes, and the images compared with angiographic infarct sizes (% of the circumference) according to the method of Feild et al. A good correlation without overestimation of the size by one method (SPECT defect = 0.93 X ventriculographic defect - 1.2%; r = 0.7, p less than 0.001) was obtained. Also a good separation of the perfusion areas of the coronary arteries due to the three-dimensional imaging with SPECT was possible. Thus, by employing Thallium-201 SPECT of the left ventricular myocardium exact localization and quantification of transmural myocardial infarcts with a positive predictive value of 98% can be achieved.
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Coded apertures supply a decoupling of resolution and sensitivity in scintigraphic imaging. The reconstructed images are focussed on different planes. The approach presented replaces the conventional collimator by three Fresnel zone plates in order to simulate a complex projection. The theoretical advantages of scintigraphy with coded apertures could be demonstrated in thyroid imaging. Unresolved artifacts and the lack of availability impair its routine use.
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Standardised third degree burn injuries were produced in guinea pigs and a standardized pseudomonas aeruginosa infection model was used. Therapy with oxygen under high pressure (OHP) was initiated for not experimentally infected burn wounds and for wounds contaminated with a constant number of bacteria from a certain pseudomonas aeruginosa strain. The healing process was documented by wound area determination, histological examination, and bacteriological evaluation. Not treated uninfected wounds showed better results than the ones that were treated with OHP. Infected burn wounds also healed better when they were not treated than the wounds in which OHP therapy was initiated with some delay. The immediate and consistent application of OHP therapy led to a significantly improved healing of burn wounds infected with pseudomonas aeruginosa.
The 250th anniversary of Georg Ernst Stahl's death (1659-1734) is the occasion for remembering the remarkable work of this Halle professor in ordinary. In the history of medicine and natural sciences Georg Ernst Stahl is imbedded on the one hand by his psychodynamistic system and on the other hand by the foundation of the phlogiston chemistry. The enactment of the Prussian Medicinal Edict of 1725, which created new criteria for the organised public health of his time, took place during the time of his function as archiater in Berlin.
The forwarding of medicaments in Halle stands in the first place in the early history of the pharmaceutic industry. The enterprise established in the years 1708/1709 worked according to economic points of view seeming modern and occupied temporarily a central position in the export business of drugs. It reached its culmination point in the second half of the 18th century. In the 19th century the export business was fused with the still nowadays existing Waisenhaus druggist 's shop in Halle.
Using varying echo-sequences, NMR studies of flow in vessels shows varying signal relationships which are caused by intermittent re-focussing of the elementary magnetic particles. By means of digital subtraction of the tomograms, this effect can be clearly shown. It has been demonstrated that this particular procedure can be used for improved visualisation of vessels and of abnormal vascular processes (thrombosis, tumours, aneurysms etc.).
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The method of operation is described, making the ligament suture safe with the hook-plate. A postoperative immobilisation is renounced by this supplying. The results of the follow-up examinations (n = 20) show no disadvantage to other operative methods. As the subjective complaints and the rate of arthrosis appear to be lower than with usual procedures of stabilisation, the supplying with the hook-plate according to Balser (additional to the ligament suture) seems to guarantee a particularly safe retention under biomechanical favourable conditions.