Radiographics : a review publication of the Radiological Society of North America, Inc
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Insufficiency fractures of the pelvis are being increasingly recognized as a major cause of low back pain in elderly women with osteoporosis. Fractures in the sacrum are difficult to diagnose, as plain radiographic findings are either unhelpful or misleading. Bone scintigraphy is very sensitive for the detection of fractures in the sacrum, with demonstration of the H-shaped (or butterfly) sacral pattern or the combination of concomitant sacral and parasymphyseal uptake being considered as characteristic of insufficiency fractures. ⋯ CT is especially useful in the further evaluation of parasymphyseal and pubic rami lesions. The majority of patients respond well to periods of enforced bed rest and administration of analgesics. Recognition of the spectrum of imaging findings for this entity should lead to its correct identification and the institution of appropriate treatment.
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Magnetic resonance (MR) imaging is useful in evaluating the wide spectrum of diseases that cause nasal masses. MR imaging is most helpful in (a) defining tumor margins and possible intracranial extension and (b) differentiating tumor (which has intermediate, heterogeneous signal intensity on T2-weighted images) from concurrent postobstructive sinusitis and other infectious or inflammatory masses (which have high, homogeneous signal intensity on T2-weighted images if the secretions are well hydrated). The analysis becomes more complicated in cases with desiccated and mixed composition secretions. ⋯ Low signal intensity on T1-weighted images and marked low signal intensity on T2-weighted images are characteristic of fungal sinusitis, and fat within a nasal mass indicates a dermoid or epidermoid cyst. Idiopathic midline granuloma, Wegener granulomatosis, and "cocaine nose" manifest as predominantly destructive midline masses. Despite the advantages of MR imaging, computed tomography remains the preferred imaging modality for evaluating nasal masses that contain calcification or originate from bone or cartilage.
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Transcranial Doppler sonography can be used to evaluate a spectrum of intracranial and extracranial vascular abnormalities. It is of proved value in the detection and follow-up of vasoconstriction caused by subarachnoid hemorrhage and can be used to demonstrate significant stenosis or occlusion of basal intracranial arteries and coexisting routes of collateral circulation. ⋯ Use of transcranial Doppler sonography enables a rapid, noninvasive diagnosis of the subclavian steal syndrome, and it is a valuable adjunct to duplex carotid sonography for determining the effect of atherosclerotic lesions of the internal carotid artery on cerebral hemodynamics. In the operating room or angiographic suite, transcranial Doppler sonography can be used to monitor patients undergoing surgical, interventional, or diagnostic procedures for the development of cerebrovascular complications.
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For treatment of radiation accident victims, procedures for handling trauma patients must be modified to ensure proper care and prevent contamination of hospital facilities and personnel. The radiation accident management plan should be instituted in advance. Exposure and contamination victims are treated differently. ⋯ After a survey to ensure that no residual contamination remains, the patient is transferred to a care unit. Effects of exposure are seen over periods ranging from days to weeks to years, depending on the total dose received. Knowing the dose allows clinicians to predict what effects may ultimately occur.