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Although echocardiography is mostly applied for the diagnosis of heart tumors there are restrictions concerning the representation of the mediastinal and cardial topography in spite of the usage of transoesophageal echocardiography. Computed tomography (CT) and magnetic resonance imaging (MR) are able to give a full representation of the heart and also the thorax with mediastinum, pleura, and lungs. Not only for the diagnosis of various kinds of heart tumors but also for decisions concerning the therapy, the detection of postoperative complications and development are CT and MR very valuable procedures. The ability to deliver a complete cross-section of all cardial, mediastinal, pulmonal and thoracic structures--in contrast to angiocardiography--and without any anatomic restrictions in contrast to echocardiography--is another advantage of CT and MR. Because of the fullness of information CT and MR supply these procedures are especially used for the detailed planning of operative procedures. They are also a big help in determining whether surgery might have to be excluded because a complete tumor resection is not possible anymore.

Left ventricular (LV) enddiastolic volume (EDV) was calculated in 23 patients from background-corrected enddiastolic count rates (ROI technique). The calculation in volume units (ml) was based on the measurement of a well-defined amount of patients' venous blood (50 ml in a syringe) counted by the gamma camera. Decrease in count rate due to tissue attenuation was corrected for by calculation of soft-tissue absorption in the thoracic and LV wall as well as the blood self-absorption within the LV, applying a rotational ellipsoid with an assumed LV depth of 1.5 times that of the LV width within the LV ROI. Furthermore, the influence of various models of LV background superimposition (homogeneous, parabolic and no background) were tested correlatively for calculations of volume. Best correlation with cineventriculographically measured volumes (r = 0.92) was found with a parabolically weighed background correction, determining an individual value of background superimposition for each LV pixel. This approach was chosen because a homogeneous superimposition is an inadequate model to correct for background due to the geometric extension of the LV. Volumes, parabolically corrected were found to correlate most closely to cineventriculography (CVG) (VMUGA = 0.997 X VCVG - 12.6 ml).

Using a prototype of an electronic, universal examination unit equipped with a special x-ray TV installation, spotfilm exposures and digital angiographies with high spatial resolution and wide-range contrast could be made in the clinic for the first time. With transvenous contrast medium injection, the clinical results of digital angiography show excellent image quality in the region of the carotids and renal arteries as well as the arteries of the extremities. The electronic series exposures have an image quality almost comparable to the quality obtained with cutfilm changers in conventional angiography. There are certain limitations due to the input field of the 25 cm x-ray image intensifier used. In respect of the digital angiography imaging technique, the electronic universal unit is fully suitable for clinical application.

150 patients were examined by the double contrast-technique in drug-induced hypotonia of the stomach. They were examined gastroscopically and at the same time biopsies were taken. Comparison of histological and radiological results was performed. There was found an agreement of 82% in the performance of areae gastricae and the histological diagnosis of chronic gastritis.

High resolution, narrow section CT examinations of the lungs were carried out on 21 Javanese macaques (five controls) shortly before the conclusion of 27 months exposure to quartz and/or high pressure. The aim was to establish morphometric CT data for differentiating and quantifying normal and abnormal findings. The results show that the technique has a high sensitivity for demonstrating the pathological lung changes. Final validation depends upon the use of respiratory physiology and biochemical, cytological, and histomorphometric data.

30 patients with myocardial infarction older than three weeks were examined by MRI prior and following intravenous injection of 0.1-0.2 mmol/kg Gd-DTPA, 201TL-SPECT and cineventriculography. Gd-DTPA did not cause any significant change (p less than 0.05) of T2-values for infarcted or non-infarcted myocardium. Compared with this, signal intensity for T1-weighted images increased after the application of the contrast agent both for normal (26 +/- 14%) and infarcted myocardium (33 +/- 16%). The intraindividual signal intensity ratio for infarcted and normal myocardium increased from 1.06 +/- 0.07 to 1.12 +/- 0.09 after the injection of Gd-DTPA. The diagnosis of myocardial infarction by visual analysis of signal intensity was not possible in individual cases. Myocardial infarction could only be visualized indirectly by morphological changes such as wall thinning and aneurysm.

The aim of the present study was to compare left ventricular myocardial changes due to infarcts, as seen by computed tomography (CT), with the clinically well recognised methods, such as electrocardiography and angiocardiography. Our first group consisted of 57 patients with a clinical diagnosis of coronary heart disease, the second group comprised 19 patients with various cardiac abnormalities. The two groups were included in 530 CT examinations of the heart. The sensitivity of CT, compared with the other methods, was 77-100%, its specificity 50-100% in the first group, which had an infarct frequency of 71-82%. In this group a positive predictive value was found in 80-100%. The second group of patients had an infarct prevalence of 13-18% and a positive predictive value of 50-100%. Sensitivity in this group rose to 100% and specificity to 86-100%.

Video-densitograms of the heart of 46 patients were obtained in three projections; these patients had clinically and angiocardiographically confirmed coronary disease of varying severity, or suffered from cardiomyopathy or were normal. The results were compared with levocardiography. The purpose of the investigation was to determine to what extent abnormalities of movement, seen on levocardiography, can also be demonstrated by video-densitometry. Our results show that video-densitometry, compared with levocardiography, has a sensitivity of 97%, a specificity of 44% and an accuracy of 86%. Video-densitometry provides definite proof of abnormal cardiac movement. The differentiation of hypokinesia from akinesia by the two methods is discussed.