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PURPOSE Generation of graspable three-dimensional objects applied for surgical planning, prosthetics and related applications using 3D printing or rapid prototyping is summarized and evaluated. MATERIALS AND METHODS Graspable 3D objects overcome the limitations of 3D visualizations which can only be displayed on flat screens. 3D objects can be produced(More)
The nuclear spin polarization of the noble gas isotopes (3)He and (129)Xe can be increased using optical pumping methods by four to five orders of magnitude. This extraordinary gain in polarization translates directly into a gain in signal strength for MRI. The new technology of hyperpolarized (HP) gas MRI holds enormous potential for enhancing sensitivity(More)
Lung imaging has traditionally relied on x-ray methods, since proton MRI is limited to some extent by low proton density in the lung parenchyma and static field inhomogeneities in the chest. The relatively recent introduction of MRI of hyperpolarized noble gases has led to a rapidly evolving field of pulmonary MRI, revealing functional information of the(More)
(a) (b) (c) (d) Figure 1: Results of three segmentation stages: (a) Region growing, (b) 2D wave propagation, (c) 2D template matching, (d) final segmenta-tion result after six iterations, taking about 76s on a PC with a P3 @ 850 MHz. Abstract Segmentation of the tracheo-bronchial tree of the lungs is notoriously difficult. This is due to the fact that the(More)
Assessment of regional lung perfusion and ventilation has significant clinical value for the diagnosis and follow-up of pulmonary diseases. In this work a new method of non-contrast-enhanced functional lung MRI (not dependent on intravenous or inhalative contrast agents) is proposed. A two-dimensional (2D) true fast imaging with steady precession (TrueFISP)(More)
The technology of multislice X-ray computed tomography (MSCT) provides volume data sets with approximately isotropic resolution, which permits a noninvasive 3-D measurement and quantification of airway geometry. In different diseases, like emphysema, chronic obstructive pulmonary disease (COPD), or cystic fribrosis, changes in lung parenchyma are associated(More)
In past decades, much effort has been invested in developing therapies for spinal injuries. Lack of standardization of clinical read-out measures, however, makes direct comparison of experimental therapies difficult. Damage and therapeutic effects in vivo are routinely evaluated using rather subjective behavioral tests. Here we show that manganese-enhanced(More)
We introduce a new model-based approach for the segmentation and quantification of the aortic arch morphology in 3-D computed tomography angiography (CTA) data for thoracic endovascular aortic repair (TEVAR). The approach is based on a model-fitting scheme using a 3-D analytic intensity model for thick vessels in conjunction with a two-step refinement(More)
UNLABELLED The purposes of this study were: to describe chest CT findings in normal non-smoking controls and cigarette smokers with and without COPD; to compare the prevalence of CT abnormalities with severity of COPD; and to evaluate concordance between visual and quantitative chest CT (QCT) scoring. METHODS Volumetric inspiratory and expiratory CT scans(More)