Der Radiologe
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Ipsilateral occlusive or embolizing carotid artery stenoses are found in 20-30% of all cases of ischemic stroke. Several randomized studies revealed endarterectomy to be the gold standard in the therapy of severe symptomatic (NASCET, ESCT) and to some extent of asymptomatic carotid stenoses (ACAS, ACST). Stent angioplasty has been established as an alternative therapeutic option although non-inferiority of this procedure has not yet been proven. We provide an overview of both procedures as well of the state of current trials.
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Although diseases of the paranasal sinuses have a relatively homogeneous clinical presentation, their causes can vary considerably. Radiological imaging only became relevant in paranasal sinus diagnostics following the introduction of cross-sectional imaging. ⋯ Particularly in acute inflammatory diseases as well as traumatic lesions, imaging is essential in preoperative planning and postoperative control. The article gives a detailed description of options in radiologic imaging of the paranasal sinuses.
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Functional magnetic resonance imaging (fMRI) is currently the primary method for non-invasive functional localization in the brain. With the emergence of MR systems with field strengths of 4 Tesla and above, neuronal activation may be studied with unprecedented accuracy. In this article we present different approaches to use the improved sensitivity and specificity for expanding current fMRT resolution limits in space and time based on several 7 Tesla studies. In addition to the challenges that arise with ultra-high magnetic fields possible solutions will be discussed.
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Functional magnetic resonance imaging (fMRI) is an important and novel neuroimaging modality for patients with brain tumors. By non-invasive measurement, localization and lateralization of brain activiation, most importantly of motor and speech function, fMRI facilitates the selection of the most appropriate and sparing treatment and function-preserving surgery. Prerequisites for the diagnostic use of fMRI are the application of dedicated clinical imaging protocols and standardization of the respective imaging procedures. ⋯ The practicability, accuracy and reliability of presurgical fMRI have been validated by large numbers of published data. However, fMRI cannot be considered as a fully established modality of diagnostic neuroimaging due to the lack of guidelines of the responsible medical associations as well as the lack of medical certification of important hardware and software components. This article reviews the current research in the field and provides practical information relevant for presurgical fMRI.
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Current diagnostic tools for the assessment of lung function are limited by global measurements or the need for radioactive tracers. Ideally, these tools should allow quantitative, regional distinct analyses without exposure to radiation. The current paper presents oxygen-enhanced functional MRI for assessment of lung ventilation. ⋯ Lower signal-to-noise ratios can be overcome by changing the relaxation times. New navigator techniques allow further compensations. This article focuses on the presentation of low-field scanners and the application of T1 and T2(*) maps is described for healthy volunteers and first patients.