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Biomedical subjects

P Landwehr

Publications and source records attributed to P Landwehr.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Risks and therapy options in dural arteriovenous fistulas between branches of the external carotid artery and the cavernous sinus. A case report and review of the literature].

INTRODUCTION: Dural arteriovenous fistula of the Arteria carotis externa and the sinus cavernosus are rare vascular malformations. In the literature the prognosis and necessity of treatment is described very variable. PATIENTS AND METHODS: A 90 year old female presents in our outpatient clinic with acute exophthalmus, dilated episcleral veins, cerebral bruits and beginning orbital apex syndrome. After normal computerized axial tomography (CAT) without and with contrast medium, we were able to diagnose a dural AV-fistula by angiography. Shortly after dismission the patient had a spontaneous subarachnoidal haemorrhage with severe neurological symptoms. CONCLUSIONS: The suspect of an intracranial AV-malformation implies a detailed diagnostic search with precise localisation of the process. In any patient with intracerebral and intracranial fistula there has to be an individual check of possible and necessary treatment. It is impossible to classify dural AV-fistula as a benign disease with harmless clinical course.

Aged↗
PubMed1995

[Value of thoracic radiography in the assessment of cardiac size. A comparison with left ventricular cardiography].

PURPOSE: To determine the value of standard chest radiographs in the assessment of cardiac size. METHODS: In 193 patients cardiac size was compared between standard chest radiographs in the posteroanterior and lateral projection and left ventricular angiograms. The following parameters were determined: transverse diameter, lateral horizontal transverse diameter, cardiothoracic ratio and end-diastolic volume index (EDVI) and ejection fraction (EF). RESULTS: Subjective assessment of the left ventricular size resulted in a mean sensitivity/specificity/accuracy of 69.7%/87.4%/82.0% respectively, in comparison to EDVI. Estimation of global heart size yielded a mean sensitivity/specificity/accuracy of 48.8%/93.6%/77.8%, respectively, in comparison to EF. Cardiothoracic ratio for the detection of pathological EDVI or EF had a sensitivity of 77.3%/57.4% a specificity of 79.3%/80.8% and an accuracy of 78.9%/72.5%. CONCLUSIONS: Standard chest radiographs with the determination of cardiothoracic ratio remain a clinically relevant procedure for screening and follow-up of heart disease.

Adult↗
PubMed1995

[Spectroscopic imaging of the brain. Examination technique and clinical applications].

PURPOSE: MR spectroscopy allows the acquisition of a two-dimensional array of spatially resolved proton spectra of the human brain, known as MR spectroscopic imaging. Here the examination protocol and clinical applications in focal brain lesions are presented. METHOD: An array of data is acquired from a tissue slice positioned in the brain. These data can be presented as a set of spectra, in which each spectrum is allocated to a specific position in the sample, or as a set of images or "metabolite maps". RESULTS: The NAA signal typical for neuronal tissue is decreased in the centre of brain tumours as well as in brain infarcts. The intensity of the choline signal is increased in solid tumour tissue, whereas it is reduced in infarcts. CONCLUSION: Spectroscopic imaging reveals metabolite alterations in and around focal lesions. The spatial resolution of spectroscopic imaging enables matching with other macro-morphological or functional imaging methods like positron emission tomography.

Adult↗
PubMed1994

[Juvenile arteriosclerosis: rare cause of generalized dilatative and stenosing vascular disease].

In addition to generalized arteriosclerosis connective tissue disease, systemic vasculitis as well as genetic metabolic disease are described to be the cause of stenotic and aneurysmatic vessel wall alteration. Although these causes are rather unusual, they must be considered for the diagnosis of a generalized vascular disease with arterial occlusion as well as aneurysm formation to determine the appropriate procedure for the individual. Whereas operative treatment should be avoided as far as possible for patients with Behçet's disease or Marfan syndrome, it is rather indicated for any kind of juvenile arteriosclerosis with arterial stenosis as well as dilatation. In this way the patient described in the following could be treated successfully by operation even though the cause of the juvenile arteriosclerosis was inexplicable, and in addition to local complications also the threatening rupture of the aneurysm could be controlled.

Aneurysm↗
PubMed1994

[Traumatic pseudoaneurysm of the axillary artery after shoulder dislocation].

By means of a case report the diagnostic and therapeutic procedures and prognosis of a pseudo-aneurysm of the axillary artery after shoulder dislocation are demonstrated. The diagnosis of aneurysms of the axillary artery is difficult in some cases. It is important to mention a possible vascular injury in case of close reduction of the shoulder. Therefore in all patients with a penetrating or blunt trauma of the shoulder or the upper arm a thorough neurovascular examination is required. In patients with neurologic deficits or alteration of the pulse a duplex ultrasound examination should be performed and in dubious cases an additional arteriography is indicated.

Aged↗
PubMed1993

[Interobserver variability of dialysis shunt flow measurements using color coated duplex sonography].

A prospective study extending over 4 months was carried out in which 142 shunt volume flow measurements were performed on 43 patients; two up to four operators with varying degrees of experience took part. Flow volumes varied between 51 and 2409 ml/min with an average blood flow volume of 521 ml/min. Comparison of measurements of individual operators showed errors of between 0.5 and 19.8%. Average error was calculated as 11.3%. Shunt flow measurements by colour Doppler sonography provide an easily appreciated and reproducible method for quantifying changes in shunt flow.

Adult↗
PubMed1992

[Taenia crassiceps infection in AIDS].

A 33-year-old patient with AIDS, and a history of episodes of Pneumocystis carinii pneumonia and cerebral toxoplasmosis, developed a subcutaneous paravertebral infiltrate, which at first resembled a haematoma. Over a period of several weeks, the lesion spread to cover almost the entire back. Initially, numerous investigations failed to reveal the aetiology. His general condition worsened progressively, and intermittent bleeding into the soft tissue of the back occurred, requiring transfusion. This was associated with the development of an isolated deficiency of clotting factor V and a fall in Quick values to 10%. On the 22nd day after admission, the infiltrate ruptured spontaneously, releasing blood and a large number of whitish spherical masses 2-3 mm in diameter. These were identified as Cysticerci longicolles, the larval form of Taenia crassiceps, a tapeworm occurring in Canidae. The blood clotting values returned to normal within two days of incision of the infiltrate and commencement of therapy with mebendazole (6 g/day) and praziquantel (3.6 g/day). The infiltrate subsequently regressed almost completely. After combination treatment for 2 weeks, treatment was continued with praziquantel alone, which, however, the patient stopped himself after 10 weeks. A recurrence at the same site 4 months later was successfully treated with a further course of mebendazole and praziquantel.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Interstitial lung diseases. A comparative study between a film-screen combination and a digital storage phosphor technic].

Chest examinations were carried out in 60 individuals using film-screen and digital storage phosphor techniques and identical radiation doses. 29 of these individuals were patients with interstitial pulmonary disease; 31 were normals. Postprocessing of the digital images was carried out with filtering using an unsharp mask and identical parameters for all patients. An ROC analysis using 10 observers showed no significant difference in the evaluation of the interstitial lung disease. Correlation analysis showed a significant positive correlation (p less than 0.001) for the findings in both techniques. Under the present circumstances, film-screen and digital storage phosphor technique are of equal value in the diagnosis of interstitial pulmonary disease.

Adult↗
PubMed1992

[The value of digital subtraction sialography compared to conventional sialography, salivary gland sonography and surgical findings].

In a prospective study DSA sialography, conventional sialography (100mm technique) and sonography of the salivary glands were performed in 124 patients. The results of imaging could be correlated with those of operation and/or histology in 70 patients. Performing sialography in only one projection DSA sialography is superior to the conventional technique. The results of DSA are equivalent to those of conventional sialography in more than one projection. DSA sialography is the method of choice demonstrating salivary calculi, whereas sonography is superior to DSA sialography in the detection of tumors. In the diagnosis of chronic inflammation of the salivary glands DSA is slightly superior to the other imaging modalities.

Adolescent↗
PubMed1992

[Pharmacokinetics of gadolinium-DTPA in chronic renal insufficiency requiring dialysis].

MRT with gadolinium-DTPA (0.1 mmol/kg body weight) was performed in 10 patients with renal insufficiency requiring dialysis and the clearance of gadolinium-DTPA was studied. After 3 dialysis on 3 successive days more than 97% of the initial concentration of gadolinium-DTPA had been eliminated. Average half-life was 1.87 hours. There were no side effects in any of the patients. Close laboratory observation of liver function showed no significant changes during the period of study. No contra-indication for the use of this contrast medium in patients with renal insufficiency requiring dialysis was found during this study.

Adult↗
PubMed1992

[The determination of myocardial mass by cardiac magnetic resonance tomography. The effect of section alignment and section distance].

The effect of section alignment and distance in volumetric determination of myocardial mass by means of cardiac magnetic resonance imaging (MRI) was studied in 19 isolated pig hearts. Double angulated views taken through the short axis of the heart with a slice thickness of 10 mm and slices at a distance of 0 mm, 1 mm, 3 mm and 5 mm produced accurate left ventricular measurements with cardiac MRI. Measurements in the long axis of the heart resulted in a marked underestimation of myocardial mass; depending on slice intervals, there was an error between 13% and 20%. In vivo measurements in 35 subjects confirmed the effect of section alignment. Measurements in the long axis of the heart produced results of 139.9 +/- 31.7 g, significantly less than measurements in the short axis of the heart of 157.8 +/- 32.3 g.

Adult↗
PubMed1992

[Response criteria for enzyme substitution in Gaucher disease].

Recently the intravenous enzyme replacement therapy with modified beta-glucocerebrosidase has become available for patients with M. Gaucher. We report here the considerable improvement of activity and vigor in a 5 year old girl with type 1 M. Gaucher administering 60 IU/kg every two weeks for 6 months. The platelet count increased from 82-96/nl to more than 150/nl and hemoglobin from 10.8 to more than 12 g/dl. Serum acid phosphatase decreased from 14.6 U/l to 5.9. U/l and angiotensin-converting enzyme from 327 to 102 U/l. The estimation of splenic volume by MRT showed a decrease by 40%, while liver size was not reduced within 6 months of therapy. MRT proved to be useful to demonstrate the bone marrow infiltration by Gaucher cells. The enzyme replacement therapy resulted in an objective response. No side effects have been observed so far. The extreme high treatment costs enforce a considerable dose reduction for maintenance therapy.

Acid Phosphatase↗
PubMed1991

[The frequency of false aneurysms of the femoral artery following heart catheterization and PTA (percutaneous transluminal angioplasty)].

In a prospective study, the arterial puncture site was studied sonographically in 1120 patients who had undergone cardiac catheterisation or angioplasty (renal or extremities). Contrary to the figures in the literature, there was an incidence of 3.84% of false aneurysms (catheters 5.26%, angioplasty 2.36%). Conventional sonography and colour-coded duplex sonography were of equal value for demonstrating false aneurysms, but colour-coded duplex sonography was superior for demonstrating their relationships and haemodynamic effects.

Adult↗
PubMed1991

[Vascular diagnosis with color-coded duplex sonography. A cost-benefit analysis].

In a retrospective study over two years, the costs of 2909 CCDS examinations were compared with 1893 digital subtraction angiograms. The cost of each CCDS examination was calculated as 147 DM and each DSA examination with intra-arterial contrast medium, or for shunt angiography was 709 DM. By using CCDS, it was possible to reduce the cost of angiographic examinations by 177,000 DM per year.

Angiography, Digital Subtraction↗
PubMed1991

[Color-coded duplex sonography of the extracranial arteries supplying the brain: diagnostic significance and sources of error in comparison with i.a. DSA].

The findings of color Doppler flow imaging of the extracranial cerebral arteries in 75 patients were compared with i.a. DSA. Carotid stenoses greater than 50% and carotid occlusions were shown by sonography with a sensitivity of 91% and a specificity of 97%. The severity of the stenosis was in agreement in 88% of cases using the two methods. Sonography of the vertebral arteries achieved a sensitivity of only 65% and a specificity of 88%. Sonographic examination of the ophthalmic artery in order to demonstrate carotid stenosis achieved a sensitivity of only 29% and provided no additional information. Retrobulbar kinking of the ophthalmic artery was found in 30/178 vessels and may be a cause of misinterpretation.

Angiography, Digital Subtraction↗
PubMed1991

[In vivo 31P-cardiac magnetic resonance spectroscopy: methods and the first clinical results].

31P-magnetic resonance (MR) spectra of the heart can be obtained from well-defined myocardial regions by combined MR imaging and variable selected volumes for spectroscopy. 31P-spectra of 33 volunteers and of 43 patients with dilated and hypertrophic cardiomyopathy and with coronary artery disease were quantified using a curve-fitting routine. To optimize our technique, we recorded unsaturated and partially saturated spectra in several volunteers. Relative peak areas and signal-to-noise ratios showed significant changes with varying pulse repetition times. Saturation factors were applied to correct spectra from volunteers and patients for the effects of partial saturation. Under resting conditions, peak areas of volunteers and patients from the various groups were statistically indistinct.

Adult↗