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Biomedical subjects

T Harder

Publications and source records attributed to T Harder.

At least 145 records · Page 8Linked to original sources
PubMed1985

[ECG-triggered DSA of the aortic arch and the supra-aortal vessels of the neck].

220 examinations were conducted in 55 patients (40 men and 15 women) to explore the question whether there are any changes in the area of the aortic arch and the supra-aortal vessels. The examinations were conducted intraindividually according to ECG-triggered and non-ECG-triggered DSA technique. The technical conditions with regard to x-ray film, volume of contrast media, and patient positions, were the same for the purpose of comparing the results with regard to the number of x-ray films, image quality, incidence of artifacts and changes in exposure to irradiation. It was found that ECG-triggered DSA yielded a greater number of diagnostically useful and qualitatively superior images with reduced irradiation exposure in a shorter time than non-ECG-triggered DSA.

Angiography↗
PubMed1984

[Two-dimensional ultrasonics--a non-invasive method for the diagnosis of arteriosclerotic changes in the region of the supra-aortic branches].

2-D ultrasound examinations were performed on 98 patients suspected of arteriosclerotic changes in the region of the extracranial arteries of the neck. The findings were compared with those obtained by angiography, including digital subtraction angiography. In 84 patients there was concordance between the results of 2-D ultrasound and angiography. In six patients the B-scan alone gave false results. In eight patients no definite diagnosis could be made. The addition of 2-D ultrasound with bidirectional Doppler reduced false diagnoses to three and uncertain diagnoses to five. The combination of 2-D ultrasound and bidirectional Doppler thus increases the diagnostic possibilities to detect arteriosclerotic changes in the region of the extracranial cervical arteries of the neck.

Angiography↗
PubMed1984

[Value of ultrasound in screening for liver metastases and liver involvement in malignant systemic disease].

The value of sonography as a primary screening method for the diagnosis of liver metastases or liver involvement by malignant lymphoma has been investigated in 163 patients. The following results were obtained: sensitivity 92%, specificity 80%, accuracy 85%. In 109 patients CT findings were also considered. The high proportion of correct positive and low proportion of low false negative findings makes sonography the method of choice for primary screening. The figures also indicate that if sonography is negative, other diagnostic procedures are unnecessary. If sonography is abnormal, but the findings are not clear, then computed tomography is indicated.

Adult↗
PubMed1984

[Venous digital subtraction angiography of the renal arteries in hypertensive patients].

We carried out 1890 venous digital subtraction angiograms; this included 113 patients with hypertension in order to exclude renal artery stenosis. On four occasions it was used following surgery on a renal artery. Renal artery stenosis or occlusion was demonstrated in twelve patients, and other vascular diseases or anomalies were found in 24. Two abnormal renal arteries were found following renal artery surgery. The results are compared with smaller groups of patients examined by DSA, and with the results of conventional subtraction methods reported in the literature. In only eight patients (6.8%) DSA provided insufficient information and had to be supplemented by aortography. The method has proved to be a valuable and simple screening method for the investigation of hypertension.

Adult↗
PubMed1984

[Digital subtraction angiography of the lung].

DSA of the lung entails reduced examination risk and is a simpler procedure than conventional angiography. Out of a total of 55 lung DSA's, 53 (96%) supplied reliable diagnostic information. Suspicion of pulmonary embolism was the most frequent indication. DSA was also successfully employed in therapy control. Since other diseases of the pulmonary vessels can also be diagnosed via DSA, it can largely replace conventional pulmonary angiography. Disadvantages of DSA which must be taken into consideration are the reduced local resolution and limitations imposed by artifacts caused by patients movements.

Adult↗
PubMed1984

[Intravenous digital subtraction angiography (i.v. DSA) of the leg arteries using a movable table].

Sixty-three I.V. DSA examinations of the lower limbs, using a movable table top, are reported. In 92% the examination was adequate. The amount of contrast required for each examination was reduced by having the movable table top. In 8% the examination was inadequate because of increased circulation time, movement of the patient during table top travel or reduced blood flow through severe or long stenoses.

Adult↗
PubMed1984

[Anatomic resolution of intra-arterial digital subtraction angiography of the kidney using different concentrations of contrast media].

In 40 patients in whom intra-arterial DSA of the kidney was carried out, the appearance of the vessels was compared between group A (20 patients) in whom 5 ml. of Iopamidol 300 mg. I./ml. and 5 ml. Iopamidol 150 mg. I./ml. were used, with group B (20 patients) in whom 5 ml. Iopamidol 300 mg. I./ml. and 10 ml. Iopamidol 150 mg. I./ml. were used. Apart from the well known advantages of intra-arterial DSA, no improvement was brought about by using lower concentration of contrast.

Angiography↗
PubMed1984

[Comparison of intra-arterial digital subtraction angiography with conventional arteriography].

Conventional arteriography and intra-arterial DSA were compared in 243 individuals for examination of the liver, kidney, lower extremity and portal vein. There was no significant difference in the diagnostic value of these methods. DSA suffers from a poorer spatial resolution in the periphery of vessels, but this has not resulted in a loss of clinically relevant information.

Analog-Digital Conversion↗
PubMed1984

[Improvement of image quality in digital subtraction angiography using a variable aperture].

The authors examine by means of comparative series in 25 patients whether and to what extent a special combination of filter diaphragms can improve imaging in digital subtraction angiography. It was found that the filter diaphragm combination should be applied as a matter of principle in case of large absorption differences in the examined region, since this will safely eliminate saturation effects causing artifacts, or partial image losses which are otherwise likely to occur. However, no essential advantages are obtained if the x-ray image is largely homogeneous.

Angiography↗
PubMed1983

[Digital video subtraction angiography of the abdominal aorta, the pelvic and leg arteries].

The arterial system can be demonstrated after intravenous contrast injection by means of DVSA. The abdominal aorta, pelvic and lower limb arteries were examined in this way in 152 patients. Occlusions, stenoses and areas of dilatation could be recognised. In 8% of the patients the aortic bifurcation or common iliac arteries were not adequately visualised. In other respects, the results of DVSA were comparable with conventional arteriography. Because of limited image size, DVSA is particularly indicated where the vascular changes can be localised accurately by clinical means. The method is well suited for observing the results of surgery or percutaneous angioplasty. The indications for arteriography have been reduced as a result of DVSA.

Angiography↗
PubMed1983

[Aneurysm of the ascending aorta with aortic valve insufficiency].

Nine cases are reported who had aneurysms of the ascending aorta and aortic valve incompetence and in whom aortic valve prostheses and aortic prostheses had to be implanted. Two patients had dissecting aneurysms. In five patients, the origins of the coronary arteries were involved, and these had to be implanted into the prostheses. Chest x-rays in two planes, kymograms and CT provided the diagnosis. The most important pre-operative examination in order to assess valve function and the origins of the coronary arteries is catheter angiography.

Adult↗
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

[Primary tumors of the mesentery and greater omentum].

Diseases of mesentery and greater omentum are commonly the result of lymph node metastases from an abdominal carcinoma, or lymph node involvement as part of a general lymphatic malignancy. Primary tumours are rare. Cysts occur predominantly in children. In addition, one may find mesenchymal benign or malignant tumours, which produce clinical symptoms at a later age. Plain abdominal films, barium meals and angiograms fail to show evidence of a space-occupying lesion, or produce only indirect signs. Only ultrasound or CT can demonstrate these tumours directly.

Adolescent↗
PubMed1983

[Digital subtraction angiography (DSA) of arteriovenous pulmonary fistulae].

A-V fistulae of the lungs are almost invariably congenital malformations; depending on their size, they may lead to the picture of a right-to-left shunt with hypoxia, cyanosis and polycythaemia. Chest x-rays, tomograms and CT demonstrate larger fistulae. In order to demonstrate small fistulae, and for pre-operative investigation, angiography is required. DSA is able to replace conventional pulmonary angiography. A patient with five A-V fistulae is described, in whom three could only be seen with the help of DSA.

Adult↗
PubMed1983

[Digital subtraction angiography (DSA) of the upper extremities].

Amongst 1500 digital subtraction angiograms, there were 93 examinations of the arteries of the upper extremities. After intravenous contrast injection, DSA provided good demonstration of the subclavian, axillary, brachial, radial and ulnar arteries. In order to demonstrate the arteries in the hand and fingers, an intra-arterial injection of 5 ml contrast into the brachial artery has proved satisfactory. DSA makes the examination easier and quicker and reduces the risk of complications. Conventional catheter angiography is now required only for a few selected problems.

Angiography↗
PubMed1983

[Secondary dislocation of a vena basilica catheter].

An extreme dislocation of a central venous line inserted from the V. basilica dextra is reported, the catheter tip being displaced from the V. cava sup., which was the correct position, to the V. jugularis int. dext., thus covering a distance of 11.5 cm. The necessary of at least one additional X-ray after 24 hours to monitor the position of the catheter is emphasised, but daily X-ray control ist not necessary.

Aged↗