Radiologia diagnostica最新文献

The comparison of mammographic image recording systems TF-13-nonscreen film and ORTHO-MA with MIN-R screens leads to the necessary conclusion, that mammography should be carried out only with screen film combinations and an anti-scatter grid. This means improved contrast and a reduction of radiation dose to 1/3 of the dose of TF 13. Since in the GDR the film XR 10 still is used as mammographic film the fourfold of the internationally possible dose is required. The urgent change of the situation can only be achieved with respective imports.

A method for measuring the fraction of extrafocal radiation in the x-ray output of x-ray tubes was developed and tested under clinical conditions. A fraction of 10% was found, that increases with tube voltage and field size, while tube current and focal spot size have no influence. As a measure for the influence of off-focus radiation on image quality the contrast transfer function was used. Off-focus radiation causes detectable geometric unsharpness. If screen-film-systems are used, the unsharpness is negligible compared with the screen unsharpness. Ways for reducing off-focus radiation from medical x-ray tubes are discussed.

Since 1969, microcatheterization (floating catheterization) of the pulmonary artery has systematically been used at the Hospital Charité in Berlin for measuring (indirectly) the left ventricular filling pressure. That seemed especially be justified in patients in whom conventional catheterization was not needed. Noninvasive techniques had not been available. Since then, our interest was focused on the hypertensive heart, earlier under the aspect of early discovering and influencing heart insufficiency, later concerning a developing myocardial ischemia, in relationship to left ventricular hypertrophy. At the Charité more than 1,000 microcatheterizations in more than 400 hypertensive cases have been performed, mostly in combination with nuclear-cardiological measurements. The rate of complications was found minimal. Thus, cardiac function could be characterized hemodynamically, at rest and even under ergometric load. Special programmes served the acute application of drugs for diagnostic or therapeutic reasons. In the meantime a longterm study could also be finished by using hemodynamic measurements, starting with hygienic means and followed by a antihypertensive basis therapy, in newly detected hypertensives. That included repeated catheterizations of the pulmonary artery.

Sonography provides a safety in dignity that is comparable to mammography while its overall sensitivity is higher. Mammography remains the method of choice. All mammographically unclear cases should be elucidated with sonography. For this reason an integration of a sonographic device and a mammography unit is advisable.

The amount of radiation committed to the patient is best described by appropriate organ doses. Methods for determining such dose values are described. For x-ray investigations of the chest, thoracic and lumbar spine, pelvis and kidney (excretion urography) our own organ-dose values are compared with those from the literature.

Experiences with embolization of the spleen artery after blunt spleen trauma in 32 patients are reported. Haemostasis by selective application of 60% glucose solution with aminocaproic acid. The method is technically simple, requires no embolization materials, and is free of postembolization complications. It preserves the organ and its function, diminishes the need for donor blood and shortens the period of hospitalization. Intraarterial application of 60% glucose solution can be used as single method of treatment or before surgery. Contraindications are massive lesions of the spleen that require immediate surgical treatment.