RöFo : Fortschritte auf dem Gebiete der Röntgenstrahlen und der Nuklearmedizin
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The imaging of systemic disorders without radiation exposure by whole-body MRI (wb-MRI) represents a paradigm shift for pediatric radiology. The reduction of multiple regional examinations, if necessary under sedation, results in a faster treatment start. Modern scanner techniques using automatic table movement and allowing the combination of multiple coil elements and synchronized signal recording with numerous independent receiving channels are the basic prerequisite for high-resolution wb-MRI. ⋯ However, wb-MRI has been shown to yield a higher diagnostic performance than bone scintigraphy and comparable results to FDG-PET for the detection of bone metastases. Due to the low number of published studies, it is uncertain for which entity of solid tumors wb-MRI is the modality of choice and for which tumors wb-MRI will play only a complementary role in the diagnostic work-up. Methodical strategies, pitfalls in image analysis, indications and diagnostic accuracy will be discussed based on already published results as well as our own experience from over 400 examinations, thus providing an overview of the recent research as well as supplying relevant aspects of the daily routine in pediatric wb-MRI.
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Magnetic resonance imaging (MRI) has become a valuable tool for diagnosing and monitoring multiple sclerosis (MS). The high sensitivity for the detection of hyperintense lesions in T 2-weighted scans contributes substantially to diagnosis. The initial lesion number or lesion volume stands for an increased probability of further accumulation of lesion burden, an earlier conversion to clinically definite MS and progression of disability in the next 5 - 15 years. This diagnostic and prognostic information gained from MRI early in the disease course lead in 2001 to a revision of the diagnostic criteria. ⋯ This review provides an updated proposal for the approach and management of cranial and spinal MR scans in patients with MS. We describe the influence of variables which cannot be standardized (scanner, field strength, manufacturer and software) and outline potential pitfalls of clinical MR imaging in MS resulting from a non-standardized approach. This updated proposal for slice positioning, sequences and documentation is a result of a consensus process targeting systematic and standardized use in clinical MR evaluations of MS.
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The spectrum of pathology affecting the central nervous system (CNS) in patients suffering from acquired immunodeficiency syndrome (AIDS) includes not only the human immunodeficiency virus (HIV) infection itself but also opportunistic infections and tumors secondary to AIDS. Despite progress in antiretroviral therapy and the subsequent decrease in the incidence of associated diseases, opportunistic infections and tumors secondary to the HIV infection continue to be the limiting factor in terms of survival with AIDS. ⋯ Magnetic resonance imaging is often the diagnostic method of choice in suspected CNS pathology of HIV patients. In the following, the typical clinical and radiological features of several AIDS-related pathologies are presented and discussed.
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Review Comparative Study
[MR-Guided pain therapy: principles and clinical applications].
X-ray fluoroscopy and computed tomography are frequently used to perform percutaneous interventions in pain therapy. The development of MR-compatible therapy needles now allows these interventions to be performed under MR imaging guidance. MR-guided interventions may be performed using most clinical MR scanners; however, systems with an open configuration are advantageous. ⋯ Fast acquisition techniques and image processing allow for continuous, near real-time MR imaging (so-called MR fluoroscopy) and interactive needle navigations, comparable to X-ray fluoroscopy and CT fluoroscopy. The purpose of this review is to illustrate and discuss general concepts of interventional MR imaging. A spectrum of interventional MR imaging procedures in spinal pain therapy is described and illustrated, including procedures such as lumbar facet joint injections, sacroiliac joint injections, lumbar spinal nerve root infiltrations and drug delivery to the lumbar sympathetic chain.
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The term whole-body magnetic resonance imaging (MRI) covers a whole series of different MRI techniques that can be used for detecting various diseases. Whole-body magnetic resonance angiography facilitates the visualization of the entire arterial system from head to toe with the exception of the coronary arteries. Whole-body MRA is clinically used for therapy planning in patients with multiple stenoses and may be able to be used in the future as a screening method for high risk populations, for example in patients with coronary heart disease. ⋯ Fast contrast-enhanced sequences can be used as an alternative approach in the search for tumors. Whole-body MRI can even be superior to a combination of positron-emission tomography and computed tomography in the detection of distant metastases. This article presents the recent developments in whole-body MRI and its established indications, which in the future might lead to a change in the paradigm for the diagnostic work-up of many diseases.