Acta radiologica
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The effect of subclavian steal on the contralateral vertebral flow and its possible effect on carotid flow were studied and the US results were compared to the angiographic findings. ⋯ A complete vertebral steal at US correlated well with subclavian occlusion and a partial steal suggested stenosis of the subclavian artery. There were also flow changes in the contralateral vertebral artery and the common carotid arteries that compensated for the steal. Retrograde vertebral flow at US was sometimes associated with vertebral occlusion in subclavian stenosis without a true subclavian steal.
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Comparative Study
Aneurysm clip MR artifacts. Titanium versus stainless steel and influence of imaging parameters.
The aim of this study was to evaluate the extent to which titanium aneurysm clips could improve the quality of MR imaging compared with stainless steel clips, and to determine whether the clip artifacts could be reduced by controlling certain MR imaging parameters in frequently used pulse sequences. ⋯ Titanium aneurysm clips reduced MR artifacts by approximately 60% compared to stainless steel clips. Artifacts were further reduced by using SE-based sequences with a high bandwidth or, if necessary, GE sequences with a low TE.
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Comparative Study
Evaluation of the post-operative lumbar spine with MR imaging. The role of contrast enhancement and thickening in nerve roots.
Two new signs of lumbar nerve-root affection have been reported in recent years on the basis of MR examinations, namely: thickening in nerve roots; and contrast enhancement in nerve roots. The aim of this study was to assess contrast enhancement in nerve roots in a standardised way, and to evaluate the clinical significance of contrast enhancement and of nerve-root thickening in the symptomatic post-operative lumbar spine. ⋯ Nerve-root enhancement (whether focal or intradural) and thickening in the nerve root are significant MR findings in the post-operative lumbar spine. In combination with disc herniation or nerve-root displacement, these two signs may strengthen the indication for repeat surgery. However, root enhancement within 6 months of previous surgery may be a normal post-operative finding.
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This investigation was conducted to determine whether MR imaging showed cerebral or spinal damage in acute diving-related decompression illness, a term that includes decompression sickness (DCS) and arterial gas embolism (AGE). ⋯ MR readily detects cerebral damage in AGE but yields low sensitivity in DCS. A negative MR investigation cannot rule out AGE or DCS. However, MR is useful in the examination of patients with decompression illness.
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To describe the introduction and performance of proton MR spectroscopy (1H-MRS) in the daily routine of a modern standard MR unit. ⋯ MRS of the brain can provide a high percentage of interpretable spectra and frequently can increase confidence in the MR diagnosis of brain lesions in clinical routine.