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  • Doppler-echocardiography  (1)
  • European forests  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Quantification of mitral valve stenosis by three-dimensional transesophageal echocardiography (1996)
    Springer
    The international journal of cardiovascular imaging 12 (1996), S. 241-247 
    Details
    ISSN: 1573-0743
    Keywords: three-dimensional reconstruction ; transesophageal echocardiography ; mitral valve stenosis ; Doppler-echocardiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of this study was the evaluation of the diagnostic potentials of transesophageal 3D-echocardiography in the determination of mitral valve stenosis. 54 patients were investigated by transthoracic and multiplane transesophageal echocardiography. In 41 patients cardiac catheterization was performed. 3D-echocardiographic data acquisition was performed by automatic transducer rotation at 2° increments over a span of 180°. The transesophageal probe was linked to an ultrasound unit and to a 3D-workstation capable of ECG- and respiration gated data acquisition, postprocessing and 2D/ 3D image reconstruction. The mitral valve was visualized in sequential cross-sectional planes out of the 3D data set. The spatial position of the planes was indicated in a reference image. In the cross-sectional plane with the narrowest part of the leaflets the orifice area was measured by planimetry. For topographic information a 3D view down from the top of the left atrium was reconstructed. Measurements were compared to conventional transthoracic planimetry, to Doppler-echocardiographic pressure half time and to invasive data. The mean difference to transthoracic planimetry, pressure half time and to invasive measurements were 0.3 ± 0.1 cm2, 0.2 ± 0.1 cm2 and 0.1 ± 0.1 cm2, respectively. Remarkable differences between the 3D- echocardiographic and the 2D- or Doppler- echocardiographic methods were observed in patients with severe calcification or aortic regurgitation. In 22% of the patients the 3D data set was not of diagnostic quality. New diagnostic information from a 3D view of the mitral valve could be obtained in 69% of the patients. Thus, although image quality is limited, 3D- echocardiography provides new topographic information in mitral valve stenosis. It allows the use of a new quantitative method, by which image plane positioning errors and flow-dependent calculation is avoided.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01797737
    Library Location Call Number Volume/Issue/Year Availability
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Overview of Recent Growth Trends in European Forests (1999)
    Springer
    Water, air & soil pollution 116 (1999), S. 33-46 
    Details
    ISSN: 1573-2932
    Keywords: growth trends ; site productivity ; European forests ; climate change ; management
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Natural environmental changes and human activities have altered forest growth for centuries. Recent long-term growth investigations indicate an increasing growth trend in European forests. The investigations are based on forest inventory, permanent plot and tree analysis data. The observed trends are species specific, locally varying and modified by remarkably large periodic growth variations. On a European scale, species and site specific quantitative information about the extent and spatial as well as temporal variation in growth acceleration is lacking. Future growth development may differ from past observations. A better understanding of changes in site conditions, their causes and consequences is needed to guide sustainable management of European forests.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005205515952
    Library Location Call Number Volume/Issue/Year Availability
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    Paper (German National Licenses)
    Fulltext
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