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Biomedical subjects

A Tschammler

Publications and source records attributed to A Tschammler.

At least 37 records · Page 2Linked to original sources
PubMed1998

Lymphadenopathy: differentiation of benign from malignant disease--color Doppler US assessment of intranodal angioarchitecture.

PURPOSE: To differentiate reactive from malignant lymphadenopathy by using color Doppler ultrasonographic (US) findings of intranodal blood vessels. MATERIALS AND METHODS: Color Doppler US was performed in 117 lymph nodes in 100 consecutive patients before performance of surgical biopsy (47 nodes), neck dissection (62 nodes), or high-speed core biopsy (eight nodes). The presence of malignant changes in intranodal angioarchitecture (focal perfusion defects, aberrant course of central vessels, displacement of intranodal vessels, subcapsular vessels) was evaluated in each node. Inter- and intraobserver variability were evaluated. RESULTS: Histopathologic examination demonstrated 48 reactive lymph nodes (longest diameter +/- standard deviation, 13.5 mm +/- 6.0), 56 nodal metastases (longest diameter, 19.2 mm +/- 8.8), 12 malignant lymphomas (longest diameter, 23.2 mm +/- 10.5), and one node infiltrated by Langerhans cell histiocytosis. At color Doppler US, 103 (88%) nodes were classified correctly, with a specificity of 77% and a sensitivity of 96%. Reproducibility was 90%-96% (kappa = 0.79-0.91, P < .001). CONCLUSION: Color Doppler US is a reliable and reproducible method for help in the differentiation between reactive and malignant alterations of superficial lymph nodes by using findings of intranodal angioarchitecture.

Adolescent↗
PubMed1996

Vascular patterns in reactive and malignant lymphadenopathy.

A total of 130 superficial lymph nodes were evaluated using color Doppler flow imaging (CDFI) in order to differentiate benign from malignant lymphadenopathy. The patterns of intranodal flow signals detected at standardized conditions by CDFI were classified using eight self-defined criteria and were correlated with the histopathological or clinical diagnosis. Nonparametric discriminant analysis showed that four vascular were suspicious of malignancy: (a) avascular areas, (b) displacement of intranodal vessels, (c) accessory peripheral vessels and (d) aberrant course of central vessels. Of the neoplastic lymph nodes (n = 73), 96% showed at least one pathological vascular pattern. Malignancy could be excluded in 95% of 57 reactive lymph nodes using these four criteria. Most reactive lymph nodes in contrast demonstrated a vascular hilus and/or vessels running at the long axis of the lymph node with branches to the cortex. There was a diagnostic accuracy of 41-82% in the additionally evaluated sonomorphological (size, shape, echogenicity) and Doppler (increased Pourcelot's or pulsatility indices) criteria. The definitive interpretation of the promising results of this retrospective study requires confirmation of examiner independency as well as a prospective evaluation.

Adolescent↗
PubMed1996

[Computerized tomography volumetry of the cerebrospinal fluid by semiautomatic contour recognition and gray value histogram analysis].

PURPOSE: A program (VAC, Siemens) using self-made, anthropomorphous phantoms to measure semiautomatically the volume of the cerebral liquor in CT scans of the whole skull was tested. MATERIAL AND METHODS: Cerebral tissue was simulated by ellipsoid bodies made from Agar and NaI which were placed in a human skull. Volumes of the ventricular and subarachnoidal liquor could be defined arbitrarily. RESULTS: A correlation coefficient of r > = 0.9 using a slice thickness of 1-5 mm was found (thickness 8 mm: r = 0.75). The volume of the cerebral liquor was underestimated by 25-68%. Separate measurements of the ventricular and subarachnoidal liquor spaces showed a high accuracy of the measurements done in the ventricles (r = 0.997, y = 0.996 x -1). The volume of the subarachnoidal liquor was not detected completely due to partial volume effects which were seen especially in the basal and apical scans. CONCLUSION: The program VAC is useful for the semiautomatic measurement of the volume of the ventricles. The assessment of the subarachnoidal liquor is limited to semiquantitative results which may, however, be useful for follow-up studies.

Brain↗
PubMed1996

[Initial experiences with dilatation of dialysis shunts with color-coded duplex ultrasonography monitoring].

PURPOSE: Aim of the study was to evaluate the technical aspects of colour coded duplex sonography guided interventions of peripheral vessels. METHODS: During 15 months 39 stenoses of shunt veins in 24 patients were dilated guided by colour coded duplex sonography. RESULTS: 38 stenoses were dilated without complications. The blood flow volume was increased from 361.9 +/- 83.5 to 718.9 +/- 189.2 ml/min. In one case it was not possible to dilate the stenosis because of a vasospasm. CONCLUSION: PTA guided by colour coded duplex sonography is an alternative to DSA guided interventions of superficial vessels without x-ray exposure or contrast agent application.

Adult↗
PubMed1996

[Value of high speed punch biopsy after mammographic stereotactic localization in diagnosis of non-palpable breast changes].

To investigate the accuracy of a single high-speed core biopsy, in 159 stereotactically localised nonpalpable breast lesions a single high-speed core biopsy was performed prior to open surgery. All pathological findings of the specimen, core biopsies and open biopsies, were compared. Two biopsies were technically insufficient. In 31 of 49 malignancies a single high-speed core biopsy revealed histologically positive results. In 108 benign lesions the benign findings were found in both samples. The specificity for diagnosis of the carcinomas was 100%, the sensitivity 63%. In lesions without calcifications the accuracy was superior to those with calcifications (88% resp. 84%). As the result of this study it is emphasised that multiple high-speed core biopsies--compared with data from recent literature--improve the sensitivity and the diagnostic value of high-speed core biopsies.

Adult↗
PubMed1995

[Sarcoidosis in monozygotic twins].

Identical (monozygotic) female twins both simultaneously developed acute sarcoidosis with unusual manifestations. Additional to pulmonary involvement they both also had hypercalcaemia with compensated renal failure. When seen at the age of 33 years, these findings were more marked in one of them (case 2) than in the other, and she also had granulomatous conjunctivitis, while in the other one (case 1) the dominant sign was widespread lymph node enlargement. Both were also found by magnetic resonance imaging to have multiple lesions in the white matter, interpreted as the morphological correlate of neurosarcoidosis. But they caused clinical symptoms (visual disorder, unsteady gait) in only one sister (case 1). Treatment with prednisolone largely normalized the lung functions in case 2, completely in case 1, and renal functions in both. But when the daily prednisolone dose was reduced to below 10 mg, the pulmonary symptoms recurred. These observations indicate that even in chronic sarcoidosis acute episodes may occur, with involvement of multiple organs and other rare complications. The manifestations of the underlying disease in identical twins and the similarities of its course in the two sisters underline the possible role of genetic factors in the pathogenesis of sarcoidosis.

Acute Disease↗
PubMed1995

Intraarticular corticosteroids for chronic arthritis in children: efficacy and effects on cartilage and growth.

OBJECTIVES: To assess the efficacy and effects on cartilage and statural growth of intraarticular corticosteroid (IAS) therapy for chronic arthritis in children and adolescents. METHODS: We examined 21 children and adolescents with chronic arthritis (median duration, 8 months) that did not respond to nonsteroidal antiinflammatory drugs. The 21 joints injected with triamcinolone-hexacetonide were examined before and 7 weeks after IAS therapy by gadolinium-enhanced magnetic resonance imaging; 14 joints were also examined 13 months after IAS therapy. RESULTS: All joints treated with IAS had improvement. Magnetic resonance imaging showed long-lasting suppression of inflammation and pannus without evidence of toxic effects on cartilage. Statural growth was not affected. CONCLUSION: In experienced hands, IAS therapy may be a safe and effective tool in the treatment of chronic arthritis in childhood. Long-term follow-up is mandatory.

Adolescent↗
PubMed1995

[Quantitative computed tomographic determination of spleen size to assess the course of malignant lymphomas].

The purpose of this study was to correlate CT-assessed spleen indices (length x width x depth) and their changes under therapy or in the follow-up, with the clinical course and morphological changes. In 66 patients with 200 CT's of the abdomen the spleen index was calculated and 134 spleen index differences (delta SI) were correlated with the clinical outcome. The normal group showed a mean of delta SI of -8 = 112, equivalent boundaries of -120 and 104. delta SI of progressive lymphomas (n = 32) was 313 (p < 0.01). In 10/14 patients of this group, morphological signs of infiltration were found. In regressive lymphomas (n = 63) we found delta SI = -211 (p < 0.001). 23/29 with delta SI < -120 showed signs of spleen involvement in the preliminary examination. Since there are only slight intraindividual changes of CT-assessed spleen indices and a good correlation of spleen index differences with the clinical outcome. the spleen index is a useful instrument in the follow-up of malignant lymphomas.

Disease Progression↗
PubMed1995

[Quantification of lymph node perfusion using color duplex ultrasonography].

PURPOSE: 20 parameters were defined to differentiate benign from malignant lymphadenopathy using computer assisted analysis of the lymph node perfusion demonstrated by colour Doppler flow imaging. MATERIAL AND METHODS: In 112 lymph nodes a computer assisted analysis of 10 consecutive colour Doppler flow sonograms was performed after digital data transfer to a work station. Planimetric results, the colour coded Doppler shift frequency, changes of the perfusion during the heart cycle and the perfusion in the adjacent tissue were analysed using 20 parameters. RESULTS: Discriminant analysis resulted in 7 parameters which reclassified correctly 82% of the lymph nodes (sensitivity 84%, specificity 80%). 72% of the lymph nodes could be classified in the three groups reactive lymphadenopathy, lymph node metastasis and malignant lymphoma. CONCLUSIONS: Clinically known subjective signs of malignancy (increased size, low echogenicity, alterations of the perfusion) can be analysed quantitatively to differentiate benign from malignant lymphadenopathy.

Diagnosis, Differential↗
PubMed1993

[Pulmonary nocardiosis].

The radiological appearances and pulmonary changes during the acute stage and after recovery from pulmonary nocardiosis are described on the basis of 10 confirmed cases. Amongst the 10 patients there were 3 with malignant disease, 1 patient with AIDS, 3 patients following organ transplantation and 3 patients on steroids. In one patient cerebral involvement was demonstrated by MRI.

AIDS-Related Opportunistic Infections↗
PubMed1993

[The computed tomographic differentiation of endobronchial tumors and tumor-caused bronchial compression].

The efficiency of computed tomography in differentiating between a bronchial compression due to tumour formation and an endobronchial tumour was tested in comparison to bronchoscopy results. 624 bronchial segments were evaluated in 65 patients with masses in the pulmonary hilus area. Computed tomographical identification of pathological lesions (n = 71) was achieved with a sensitivity of 83% and a specificity of 96%. Out of 52 bronchial segments with endobronchial tumour, 90% showed pathological lesions and 85% were classified correctly. When the morphology of the bronchial lesions (endoluminal mass, smooth or irregularly demarcated bronchostenosis or bronchial displacement) was assessed with CT, only the CT identification of an endoluminal mass could distinguish endobronchial tumour growth with a probability of 91% from bronchial narrowing due to external causes and normal bronchi.

Adult↗
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↗
PubMed1991

[The diagnostic assessment of enlarged lymph nodes by the qualitative and semiquantitative evaluation of lymph node perfusion with color-coded duplex sonography].

Perfusion of enlarged lymph nodes by colour-coded sonography was studied prospectively in 105 benign and 115 malignant lymph nodes. The diagnosis was confirmed histologically in 158 and clinically in 62. Spectral analysis in the benign lymph nodes provided normal values for pulsatility and resistance indices. A pulsatility index greater than = 1.8, or a resistance greater than = 0.9 indicate lymph node metastases with positive prediction of 93% and specificity of 97%. In addition, subjective, semiquantitative classification of lymph node perfusion in relation to the surrounding fat or connective tissue improves the diagnosis of lymph node metastases and of malignant lymphomas.

Axilla↗
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↗