Der Radiologe
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Review Comparative Study
[Whole-body diffusion-weighted imaging in oncology: technical aspects and practical relevance].
This review illustrates the relevance of whole-body diffusion-weighted imaging (WB-DWI) in the field of oncological imaging. WB-DWI is an alternative method to positron-emission tomography/computed tomography (PET/CT) due to the lack of radiation and lower examination costs. Technical aspects of WB-DWI and the current role of the method in cancer imaging regarding practical requirements in oncology are presented.
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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.
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Scaphoid fractures, which involve approximately two-thirds of all wrist injuries, are often not detected during initial radiographic examination. By using high-resolution CT and dedicated MRI, it is possible to recognize scaphoid fractures soon at the first diagnostic approach and to assess fragment stability. ⋯ Both the initially overseen scaphoid fracture and the unsuccessful healing can lead to the natural history of scaphoid nonunion. In the injured scaphoid, CT imaging is essential for depicting the osseous morphology, whereas contrast-enhanced MRI is crucial for assessing the viability of the proximal fragment.
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To evaluate characteristic and reliable MRI patterns of different inflammatory lesions of the spinal cord and the nerve roots in immunologically compromised and immunologically competent patients in order to be able to establish a correct diagnosis based on MRI findings. ⋯ Secondary ischemic and demyelinating processes result in a complex morphology of inflammatory lesions on MRI, and therefore the whole spectrum of demyelinating, ischemic and inflammatory lesions has to be included in the differential diagnosis. Even tumors may imitate inflammatory myelitis and radiculitis. Most commonly, meningoradiculitis can be separated from myelitis. A reliable diagnosis of a specific inflammatory lesion is difficult and is mostly achieved in patients with multiple sclerosis and in patients with HIV-associated cytomegalovirus infection.
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If properly performed, modern high-resolution real-time ultrasonography will disclose subtle differences in the texture of thyroid tissue and thereby enable the examiner to suggest a diagnosis. Nevertheless, there is often a need for a more specific diagnosis of solid or semisolid thyroid lesions - especially when the lesion might be malignant. Ultrasonically guided fine-needle aspiration biopsy (UG-FNB) allows a final cytological and/or histological diagnosis to be made in patients with benign or malignant space-occupying growths even if they are small. ⋯ Since the tip of the needle can be visualized on the scan, the needle may be advanced or withdrawn during aspiration so it is possible to empty the cyst completely. The use of ultrasound in the follow-up of patients with thyroid cyst puncture is mandatory to evaluate the results. Surgical therapy should be reserved for large cysts causing space-occupying complications.