RöFo : Fortschritte auf dem Gebiete der Röntgenstrahlen und der Nuklearmedizin
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Clinical Trial
[Contribution of early systole to total antegrade flow volume in breath-hold phase-contrast flow measurements].
To evaluate the contribution of early systole for the assessment of antegrade aortic flow volume by breath-hold velocity-encoded magnetic resonance (MR) flow measurements. ⋯ Flow during early systole contributes substantially to total forward flow volume in the ascending aorta. Interpolation of the early systolic up-slope is therefore recommended for the evaluation of breath-hold phase-contrast flow measurements.
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To study quantitative changes of lung density distributions when recording in- and expiratory static pressure-volume curves by single slice computed tomography (CT). ⋯ Recruitment and derecruitment of lung atelectasis during registration of static in- and expiratory pressure-volume loops occurred constantly, but not in a stepwise manner. CT was shown to be an appropriate method to analyse these recruitment process.
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Current imaging methods of the lung concentrate on morphology as well as on the depiction of the pulmonary parenchyma. The need of an advanced and more subtle imaging technology compared to conventional radiography is met by computed topography as the method of choice. Nevertheless, computed tomography yields very limited functional information. ⋯ Oxygen sensitive imaging displays intrapulmonary oxygen partial pressure and its distribution. Currently, the method is limited by comparably high costs and limited availability. As there have been recent developments which might bring this modality closer to clinical use, this review article will comprise the methodology as well as the current state of the art and standard of knowledge of magnetic resonance imaging of the lung using hyperpolarised (3)Helium.
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Comparative Study Clinical Trial Controlled Clinical Trial
[Comparison of a T1-weighted inversion-recovery-, gradient-echo- and spin-echo sequence for imaging of the brain at 3.0 Tesla].
The increased T1 relaxation times at 3.0 Tesla lead to a reduced T1 contrast, requiring adaptation of imaging protocols for high magnetic fields. This prospective study assesses the performance of three techniques for T1-weighted imaging (T1w) at 3.0 T with regard to gray-white differentiation and contrast-to-noise-ratio (CNR). ⋯ For unenhanced T1 w imaging at 3.0 T, the IR technique is, despite increased artifacts, the method of choice due to its superior gray-white differentiation and best overall image quality. For CE-studies, GE sequences are recommended. For cerebral imaging, SE sequences give unsatisfactory results at 3.0 T.