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Biomedical subjects

K F Neufang

Publications and source records attributed to K F Neufang.

At least 37 records · Page 2Linked to original sources
PubMed1990

[Diagnosis and differential diagnosis of a peritoneal carcinosis. Conventional techniques, sonography, computed tomography, magnetic resonance tomography].

Based upon the results obtained in 346 patients, the diagnostic value of conventional techniques, ultrasonography, computed tomography and magnetic resonance imaging in the detection of peritoneal tumor spread is analyzed. Since such signs as ascites, mesenteric and omental infiltration and peritoneal masses are non-specific, various conditions have to be considered in the differential diagnosis. None of the imaging modalities can exclude intraperitoneal tumor spread.

Carcinoma↗
PubMed1990

[Effect of the geometry of atherosclerotic carotid artery lesions on their angiography image--an arteriography study].

Atherosclerotic lesions of the carotid arteries are frequently located eccentrically and are of asymmetric configuration. For their angiographic detection at least two orthogonal views are mandatory. The carotid bifurcations, the proximal internal carotid artery and the carotid siphon can be visualised free from vessel overlap only via often mandatory lateral views that must be obtained by selective arteriography (IA DSA). Smaller lesions and ulcerations of the carotid bifurcation area may be misinterpreted with nonselective IA DSA and IV DSA because of their geometry.

Adult↗
PubMed1990

[Assessment of the grading of cartilaginous tumors of the long tubular bones from the radiologic and pathologic viewpoint].

Based on 46 enosteal cartilaginous tumours of the long tubular bones (43 patients) the established radiological and Mirra's histopathological criteria of tumour status are assessed independently and compared retrospectively. In lesions of Lodwick's type I B (37 cases) with mineralisation of the cartilaginous matrix and facultatively cortical arrosion, lack of periosteal reaction, destruction of the corticalis and parosseal tumour extension none of Mirra's histopathological criteria of malignancy was found. It may be expected that biopsy and histopathological examination will not give valuable additional information in this radiological constellation, because there are no known definite histopathological criteria of benignity. Suspicious radiological findings should prompt complete resection of the lesion. Biopsy and histopathological classification are always crucial when matrix mineralisation is lacking and therefore the diagnosis of a cartilaginous tumour cannot be established radiologically.

Adult↗
PubMed1989

[Status of the captopril test in the diagnosis of hypertension].

The place of captopril (C) testing in the screening for renovascular hypertension is still controversial. Baseline and C-stimulated plasma renin concentrations (PRC) were measured in 113 hypertensives, who where referred for the exclusion of secondary hypertension. In addition intravenous digital subtraction angiography (DSA) and a renal scintigraphy were performed. When renal artery disease was revealed by DSA or renin was stimulated the renal arteries were visualized by direct arteriography (and treated by angioplasty if possible). 86 patients underwent each diagnostic test: 21% had renovascular hypertension. Unilateral renal artery stenosis (n = 10) was detected by the captopril test (cutoff values: baseline greater than 40 microU/ml, after C greater than 180 microU/ml, sensitivity 100%). Bilateral renal artery stenosis (n = 8) was missed when the disease was equally severe on either side (sensitivity 50%). The specificity of C testing was 82%, overall sensitivity (uni- and bilateral disease 78%, prevalence 21%, predictive value of the positive test 0.56, predictive value of the negative test 0.93). With i.v.-DSA the renal arteries were technically evaluable in 91% (82/92) of cases. The sensitivity for the detection of all renal artery stenoses was 79% (uni-lateral 100%, bilateral 40%, specificity 97%). The sensitivity of renal scintigraphy for the detection of unilateral renal artery stenoses was 50%, for the detection of bilateral renal artery stenoses 43%, specificity 81%. The present study demonstrates the usefulness of captopril for the detection of unilateral renal artery stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Pleuromediastinal lines in infants, children and adolescents--a contribution to knowledge of the normal x-ray anatomy of the mediastinal borders].

The roentgen anatomy and incidence of the most frequent pleuromediastinal lines and stripes (PML) on the sagittal chest film during the first 18 years of life are analysed. It is only on involution of the thymus that the PMLs of the superior mediastinum (anterior contact line, right paratracheal stripe, arteriovenous left subclavian lines, "aortic nipple", supra-azygous posterior pleural line) are modelled out. Between the 2nd and 6th year of life they attain their normal appearance typical for adult life. The PMLs of the posterior inferior mediastinum (paraspinal lines, infra-azygous posterior pleural line) are most frequently observed between the 6th and 18th year of life. Absence of a PML as a single finding is not pathological. Displacement, widening or opacification of a PML, specially if they affect only a segment of the PML, may be indicators of a pathological process within the mediastinum itself or in the adjacent lung or pleura.

Adolescent↗
PubMed1989

[Thoracic aorta dissection--the place of MRT and CT in the follow-up after prosthetic aortic replacement].

Dynamic CT and MRT were performed in 21 patients who had undergone prosthetic replacement of the aorta because of dissection of the thoracic aorta. There is no difference between MRI and dynamic CT in the demonstration of a persistent intimal flap, the formation of a thrombus and the assessment of the aortic diameter in patients who underwent surgery for thoraco-abdominal aortic dissection. MRI, however, is superior in the identification of the true and false lumen and the demonstration of the distal anastomotic site. The major advantages of MRI are that there is no need for intravenous contrast agents, that it is highly sensitive to flow phenomena, and that it can demonstrate the aortic arch and the ascending aorta on sagittal oblique sections. The major disadvantages of MRI are the limited access to the patient during the procedure, and the inability to examine patients fitted with pacemakers or who are on assisted ventilation. Today, MRI is considered the method of first choice for the postoperative follow-up of patients who underwent surgery for aortic dissection.

Adult↗
PubMed1989

[What does radiologic diagnosis of the thymus gland accomplish in myasthenia gravis?].

Radiologic imaging in myasthenia gravis is used for the evaluation of pathologic changes of the thymus gland. Computed tomography can demonstrate tumors of the anterior mediastinum in nearly 90% and is therefore superior to conventional radiography. Because of the variety of size and shape of the normal thymus gland, differentiation between normal thymus, follicular hyperplasia and thymoma is rarely possible especially in younger patients. In elderly patients with myasthenia gravis and involution of the thymus gland tumors of the thymus are reliably detected by computed tomography, whereas the ability of computed tomography to predict the histological diagnosis is poor even with intravenous administration of contrast media.

Humans↗
PubMed1989

[Distribution pattern of atheromatous lesions of the carotid circulation--significance for the angiographic strategy of cerebrovascular insufficiency].

Atherosclerosis of the cervico-cerebral arteries is a generalized disease which frequently involves the whole carotid system. The bifurcations (48.7%), the proximal 2 cms. of the internal carotid arteries (61.6%) and the carotid siphons (60.3%) are most frequently affected. Angiography may demonstrate ulcerated lesions in up to 25% of cases. "Tandem stenoses" in both the extracranial segments of the carotid arteries (4.6%) and isolated hemodynamically significant stenoses in the carotid siphons (.7%) are uncommon. Nevertheless their presence may play an essential role in therapeutical decision making. Because of the multiplicity of lesions, the claim for preoperative selective arteriography is justified. IA DSA may replace film angiography, if image quality and medical information are identical. IV DSA and Doppler-procedures as a rule cannot replace selective arteriography in preoperative work-up.

Adult↗
PubMed1989

[Equipment and methodologic parameters of radiation exposure in digital subtraction angiography].

The mutual dependence of various parameters--frame rate, radiation dose per frame, size of the image intensifier field, photon energy, frame mode, and patient diameter--is investigated systematically on a modern DSA equipment. The software programme of the DSA machine widely modifies these parameters according to the individual conditions, which may influence both radiation exposure and image quality. IV DSA requires low photon energies to exploit the low iodine signal. Higher frame rates, oblique views and small image intensifier fields should be used restrictively especially in the abdomen, as they tend to lower the radiation doses per frame and to increase photon energies, thus impairing contrast resolution. Full understanding of the physical and technical basics and familiarity with the software programme of own DSA machine are mandatory to allow appropriate selection of the various parameters, according to the individual patient and his/her diagnostic problems. They are the key to optimal imaging quality at a tolerable radiation exposure.

Angiography↗
PubMed1988

Digital subtraction angiography: the intravenous approach.

With further improvement of digital subtraction angiography (DSA) equipment, and the development of sophisticated soft-ware programs, the intravenous approach again has become an promising diagnostic alternative in certain clinical settings, if the patient's cardiac output is not severely diminished. In many cases an additional arterial study is not necessary. The diagnostic results, advantages and limitations of the intravenous approach in imaging the brachiocephalic, renal and peripheral vessels are discussed.

Angiography↗
PubMed1988

[Abdominal real-time sonography in patients with vascular prostheses].

100 sonograms were performed in 71 patients up to 13 years (average 21.8 months) after various surgical interventions of the abdominal aorta. Patients were examined e.g. for complications in the early postoperative stage or abnormal local findings and during clinical follow-ups. Ultrasound showed e.g. 13 aneurysms of grafts and anastomoses, 19 haematomas, 4 lymphoceles, 3 graft occlusions and 2 graft infections. Beyond the implantation site in 45 sonograms additional pathological findings were demonstrated, which were unknown in 13 patients (e.g. renal carcinoma, liver metastases, hydronephrosis). In patients with aortic grafts real-time sonography of the abdomen can be regarded as a relatively easily performed, valuable method.

Adult↗
PubMed1988

[Treatment of arterial occlusions of the lower extremities using 2-stage local application of urokinase].

We report the results of a 2-phase urokinase protocol for treatment of 28 arterial occlusions of the lower extremities. 26 patients, aged 43-86, with up to 6 weeks old occlusions were treated. In Phase I (average duration 2.7 h) the urokinase solution was injected in intervals directly into the occlusion-material via a F-5 catheter (120,000 U/h). In the following phase II (average duration 26.1 h) 100,000 U/h were given as a continuous arterial infusion and a full heparin regimen was started. In 86% of the treatments there was an improvement as shown by angiography. 75% of the patients could be released from the hospital without a further surgical revascularisation. Alterations of the systemic coagulation-system and bleeding-complications at the puncture site must be expected.

Aged↗
PubMed1988

[DSA in the postoperative diagnosis of patients with kidney transplants].

Image quality and diagnostic significance of intravenous and intraarterial DSA following renal transplantation were assessed in 40 angiographic studies. In 27 of 40 DSA (67.5%) there were pathologic findings such as a renal artery stenosis, aneurysms or rejection within this selected group of patients. There were significant differences in image quality between intravenous and intraarterial DSA. The value of intravenous DSA is limited, particularly in patients with complex anastomosis, implanted polar arteries and kinking stenosis.

Adult↗
PubMed1987

[Diagnosis of renovascular hypertension using venous DSA (digital subtraction angiography): image quality and predictive value 1987. Determination of current status].

Using optimal equipment and an adequate examination technique, renal venous DSA for renal artery stenosis is today a diagnostic procedure in 98% of cases. Its sensitivity equals 85%, its specificity reaches 95%. Comparing accuracies and positive predictive values, renal venous DSA is superior to radionuclide studies. Pre-selection of patients with captopril as a pharmacologic test is expected to increase the predictive values of renal venous DSA and to confirm the hemodynamic significance of an angiographically detected renal artery stenosis.

Adolescent↗