[Technical quality assurance in diagnostic ultrasound in outpatient care in Germany]. / Technische Qualitätssicherung der Ultraschalldiagnostik in der ambulanten Versorgung.

PURPOSE: Technical quality assurance in diagnostic ultrasound is based on nationally standardized protocols which are mandatory for outpatient care in Germany. Quality assurance includes technical requirements for sonographic instruments based on limiting values for technical parameters and requirements for image quality and documentation. Certification by regional Associations of Statutory Health Insurance Physicians (Kassenärztliche Vereinigungen - KV) requires acceptance tests to prove compliance with all required standards. MATERIALS AND METHODS: Between April 2009 und December 2011a total of 7457 acceptance tests were performed by the KV Westfalen-Lippe, which represents nearly 13 000 physicians in northwestern parts of Germany. Results of these acceptance tests are evaluated with respect to display mode or Doppler technique, anatomic region and year of manufacture of the instruments. RESULTS: In 2469 acceptance tests (33 %), objections were raised, mainly due to noncompliance with technical parameters. The frequency of objections strongly increases with the age of sonographic instruments and exceeds 90 % for instruments manufactured before 1995. In acceptance tests where compliance with technical parameters has been approved, insufficient documentation was reported in 6 % and inadequate image quality in 8 % of the tests. Frequency and cause of objections depend on display mode and anatomic region. CONCLUSION: The study shows that sonographic instruments of higher age often do not meet the required standards, and it can be expected that updates in technical equipment will result in improvements in diagnostic performance and clinical outcome.

[Diagnostic image quality of mammograms in german outpatient medical care]. / Die diagnostische Bildqualität von Mammografien in der vertragsärztlichen Versorgung Deutschlands.

PURPOSE: A total of 79115 mammograms from statutory health insurance (SHI) physicians within German outpatient care were evaluated with respect to the diagnostic image quality. MATERIALS AND METHODS: Mammograms were randomly selected between 2006 and 2008 by the regional Associations of Statutory Health Insurance Physicians and submitted to regional boards of experts for external evaluation. The mammogram quality was evaluated using a 3-point scale (adequate, borderline, failure) and documented using a nationally standardized protocol. RESULTS: 87.6% of the mammograms were classified as adequate, 11.0% as borderline and 1.4% as failure. Mediolateral oblique mammograms (mlo) had worse ratings than craniocaudal mammograms (cc). Main reasons for classifying the mammograms as borderline or failure were "inframammary fold not adequately visualized" (mlo), "pectoral muscle not in the correct angle or not to the level with the nipple" (mlo), "the nipple not in profile" (mlo, cc) and "breast not completely or not adequately visualized" (cc). CONCLUSION: The results show a good overall quality of mammograms in German outpatient medical care. Failures can be associated predominantly with incorrect positioning of the breast. More precisely defined quality criteria using objective measures are recommended, especially for craniocaudal mammograms (cc).

Non-arrhenius behavior of the island density in metal heteroepitaxy: Co on Cu(001).

We present a combined theoretical and experimental study of island nucleation and growth in the deposition of Co on Cu(001)-a prototype for understanding heteroepitaxial growth involving intermixing. Experimentally, ion scattering is employed. Using density-functional theory, we obtain energy barriers for the various elementary processes and incorporate these into a kinetic Monte Carlo program to simulate the heteroepitaxial growth. Both the simulations and the experiments show a unique N-shape dependence of the island density on temperature that stems from the interplay and competition of the different processes involved.

Ion beam triangulation of ultrathin Mn and CoMn films grown on Cu(001).

Total target currents for grazing scattering of keV protons from a crystal target are used to investigate the structure of surfaces and ultrathin films. This current shows pronounced maxima whenever the azimuthal incidence angle coincides with close-packed rows of atoms in the surface and subsurface layers. The real-space method is applied to study monolayer and bilayer films of Mn and of CoMn epitaxially grown on a Cu(001) surface.

Spin-polarized electrons in collisions of multicharged nitrogen ions with a magnetized Fe(001) surface.

We report on the first spin-resolved energy spectra for the emission of electrons during grazing scattering of 150 keV multicharged nitrogen ions from a magnetized Fe(001) surface. A substantial spin polarization for KLL Auger electrons emitted in the final stage of the neutralization sequence during the interaction of multicharged ions with a metal surface is observed. We conclude from our data that the projectile L shell is dominantly populated by electrons from the conduction band of the target. For low energy electrons we find an increase of their spin polarization with an increase of the projectile charge.