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Biomedical subjects

P Thurn

Publications and source records attributed to P Thurn.

At least 19 recordsLinked to original sources
PubMed1988

Conventional computerized tomography of the heart.

Ungated cardio-CT provides good morphologic information in the case of congenital heart disease, volume or pressure loading, left ventricular aneurysm, tumours, thrombi, cardiac calcifications and pericardial diseases. It allows qualitative assessments of myocardial thickness and perfusion of coronary bypass grafts. ECG-gated cardio-CT allows a quantitative assessment of systolic and diastolic myocardial thickness, volume calculation of cardiac cavities and evaluation of functional parameters. The correlation of the calculated left ventricular ejection fraction comparing laevocardiography and ECG-gated cardio-CT was poor (r = 0.7) mainly due to the comparable poor time resolution on the side of cardio-CT (approximately 0.1s). The quantitative analysis of regional wall motion based on cardio-CT showed for the diagnosis of pathologic wall motion a specificity of 80.5%, sensitivity of 73.9% and accuracy of 75.7%. Side effects must be taken into account following the injection of 200-250 ml hyperosmolar contrast medium during 5-10 minutes which causes intravascular fluid retention and cardiac volume loading. Patients prone to cardiac decompensation should be excluded from cardio-CT examinations.

Cardiomyopathy, Dilated↗
PubMed1988

[Color Doppler sonography: non-invasive potential for morphologic and functional vascular diagnosis].

A linear array colour Doppler sonographic method was used experimentally on a vessel phantom in order to determine flow velocity, and the results were compared with DSA. Both the Doppler and the DSA method showed very good agreement with true velocities (r greater than 0.97). The Doppler method underestimated flow velocity. Early clinical results indicate that colour Doppler sonography is able, at the same time, to demonstrate morphology and function (direction flow and flow velocity) of significant vascular abnormalities by a non-invasive method.

Blood Flow Velocity↗
PubMed1987

[Cardiac MRT. Research technic and topographic anatomical imaging information].

ECG-triggered cardio-MRT, using T1-weighted SE sequences, provides images of the heart showing very high anatomical resolution. So far, however, it has not been possible to demonstrate the morphology of the valves and coronary vessels. By using multiplanar sections, it is possible to obtain cuts which are perpendicular to the portion of myocardium or valve under consideration. This provides optimal imaging for morphological diagnosis and for evaluating the ventricular myocardium and its function.

Coronary Vessels↗
PubMed1987

[Rapid MR tomography of the liver. Technic and initial results].

The fast-field-echo (FFE) sequence provides a new rapid imaging method for MR tomography. By using gradient echoes with shorter high frequency pulse repetitions than conventional sequences with 180 degrees echo pulses, it is possible to produce single cuts in 10 to 20 s with good signal-to-noise ratio. In this way the liver can be examined while respiratory movement artifacts are reduced. The possibility of obtaining T1- and T 2-weighted FFE images with good contrast resolution and the ability to determine relaxation times suggests a wide application of this rapid imaging procedure in the diagnosis of liver disease.

Carcinoma, Hepatocellular↗
PubMed1987

[Quantifying aortic valve insufficiency by digital subtraction aortography].

The purpose of this study was to assess the contribution of digital subtraction angiography (DSA) to the quantification of aortic valve regurgitation in 21 patients undergoing heart catheterization. The digital image subtraction was used for densitometric evaluation. The regurgitation was derived from the distribution of contrast volumes during diastole in aortic and left ventricular "regions of interest". DSA-measurements were compared with results of conventional cineangiography. Results showed the following correlation between DSA measurements and cineangiographic estimates (grades I-III): regurgitation 1.7-9.8% in grade I (n = 11), 8.9-22.3% in grade II (n = 5), 31.7 and 32.5% in grade II-III (n = 2), 37-42.4% in grade III (n = 3). DSA and digital densitometry seem to be valuable methods for the quantification of regurgitation. Concerning quantitative measurements in left heart catheterization the digital subtraction aortography is superior to conventional cineangiography and will be helpful to characterize patients with aortic regurgitation more completely.

Adult↗
PubMed1985

[Morphometric and densitometric assessment of left ventricular function in the digital subtraction angiocardiogram].

The paper deals with the early clinical experience, using a new DSA installation with a specially programmed cardiological module. DSA provides very good contrast and special resolution and morphometric estimation of the ejection fraction and regional movement of the left ventricular myocardium derived from DSA. This is as good as the results of the left cardiogram. The significant advantage of DSA ist the ability to make a rapid and simple diagnosis. In addition, it is possible with densitometric methods to calculate ventricular volume curves and to provide phasic indications of the amplitude to contraction of the left ventricle. These investigations have so far proved valuable and provide new scope for the radiological evaluation of left ventricular function.

Absorptiometry, Photon↗
PubMed1983

[Digital subtraction angiocardiography].

One hundred patients with a variety of cardiac abnormalities were examined by digital subtraction angio-cardiography; the quality of the image was almost as good as conventional cinecardiograms. Image frequency of 25 pictures per second provides a reliable analysis of cardiac contraction and, in many situations, makes it unnecessary to perform selective angio-cardiography. Compared with selective catheter techniques, digital subtraction cardiography has various advantages. Because of its low risk and small patient stress, it is particularly suitable for follow-up examination after various therapeutic measures.

Adult↗
PubMed1983

Phantom measurements and error estimation in volume determination with ECG-triggered cardio-computed tomography.

The ECG-triggered CT-imaging-procedure (computed tomography system SOMATOM with ECG unit) provides the possibility of displaying the beating heart in each of its individual mobility phases. Thus the telediastolic and telesystolic volumes of the left ventricle can be determined approximately, and from this its ejection fraction. The present paper describes measurements on moving phantoms (acryl plate, fluid-filled balloon). They give an estimation of the accuracy with which cross-sectional areas can be determined by the above-mentioned CT-system as a function of the frequency of the movement and of the number of tube rotations per slice. Basing on those models and not paying regard to further sources of error as for example an irregular heartbeat, it is found that the ejection fraction can be determined with a relative error of +/- 11% . . . +/- 13% depending on the beat frequency.

Cardiac Output↗
PubMed1982

[Coronary artery aneurysms (author's transl)].

Seven saccular coronary artery aneurysms have been demonstrated in the course of 1452 selective coronary artery angiograms. In six patients they were arterio-sclerotic; in one patient the aneurysm must have been congenital or of mycotic-embolic origin. The differential diagnosis between true aneurysms and other causes of vascular dilatation is discussed. Coronary artery aneurysms have a poor prognosis because of the possibility of rupture with resultant cardiac tamponade, or the development of thrombo-embolic myocardial infarction. These aneurysms can only be diagnosed by means of coronary angiography and require appropriate treatment.

Adult↗
PubMed1982

[Experimental myocardial infarct in computerized tomography].

The findings on computer tomography after ligation of the coronary artery of a dogs heart are described. The ischaemic area can be differentiated from normal myocardium by its hypo-dense appearance. The localisation and size of the ischaemic area correlates with the scintigraphic findings. The known morphological and functional changes after intravenous oxyfedrin (positively inotropic, increased myocardial blood-flow) can also be seen on the computer tomogram (after oxyfedrin: myocardial thickening, reduction in cross-sectional area of the left ventricle, improved contraction, increased density of the ischaemic area). This confirms the possible diagnostic role of CT in the elucidation of changes in the left ventricle in the course of coronary disease.

Animals↗
PubMed1981

Computed tomography of the heart: ECG-gated and continuous scans.

Cardiac computed tomography (cardiac CT) and echocardiography provide noninvasive diagnosis of cardiac lesions by direct demonstration of the myocardium and the individual cavities of the heart. Myocardial thickness, and the size and shape of heart cavities are easily demonstrated. In patients with coronary heart disease proved by levocardiography, cardiac CT gave a true negative rate of 82.3% (echocardiography 82.9%) and a true positive rate of 90.8% (echocardiography 82.7%). In the assessment of coronary bypass graft patency, cardiac CT was accurate in 89.6% of studies confirmed by angiography.

Cardiomyopathies↗
PubMed1981

[Computer tomographic diagnosis of cardiac, pericardial and paracardial space occupying lesions].

By means of the pathological findings of 63 patients diagnosed by CT of the heart the radiodiagnostic signs of myocardial, pericardial and paracardial space occupying processes are demonstrated with emphasis on CT of the heart. In addition the electrocardiographic findings of 46 patients are compared with the CT-findings. Whereas there are no essential differences between the results of the two methods diagnosing intramural and greater intracavitary tumors, CT is to prefer at the differential diagnosis of pericardial and paracardial tumors. CT is superior to echocardiography diagnosing small intracavitary thrombi.

Coronary Disease↗
PubMed1980

[The value of computer tomography in the staging of primary lymph node neoplasms (author's transl)].

Staging was undertaken in 118 patients with primary lymph node neoplasms; the sensitivity of computer tomography in the paraaortic region was 80%, that of lymphography 89%. Specificity of computer tomography was 93%, of lymphography 95%. In the iliac region, sensitivity was 81% (CT) and 90% (lymphography), and specificity was 90% (CT) and 97% (Lymphography). The value of computer tomography should, however, be stressed, since it can demonstrate lymph nodes not shown by lymphography, including those in the mediastinum, as well as lesions in the spleen, liver and lungs.

Adolescent↗