Journal of computer assisted tomography
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J Comput Assist Tomogr · Jan 2005
Differential diagnosis between cerebral tuberculosis and neurocysticercosis by magnetic resonance spectroscopy.
Single enhancing brain lesions (SELs), mostly as a result of neurocysticercosis or tuberculosis, are a common cause of seizures. Ten patients with SELs caused by neurocysticercosis (n=6) or tuberculosis (n=4) were examined by proton magnetic resonance spectroscopy. ⋯ The choline/creatine ratio was greater than 1 in all tuberculomas but in none of the cysticerci. Magnetic resonance spectroscopy differentiates SELs caused by cysticercosis or tuberculosis and may avoid brain biopsies or unnecessary antituberculosis treatments.
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J Comput Assist Tomogr · Nov 2004
Comparative StudyComparison of perfusion computed tomography with diffusion-weighted magnetic resonance imaging in hyperacute ischemic stroke.
In this study, perfusion CT and diffusion-weighted magnetic resonance imaging (DWI) were compared as means of assessing the ischemic brain in hyperacute stroke. ⋯ Both imaging modalities provide a sufficient assessment of the hyperacute brain infarct, with significant correlation between them and the clinical condition at admission. Perfusion CT allows differentiation of the penumbra and infarct core region with significant predictive value of follow-up infarct volume and clinical outcome.
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J Comput Assist Tomogr · Nov 2004
Comparative StudyAmyloidosis and lymphoproliferative disease in Sjögren syndrome: thin-section computed tomography findings and histopathologic comparisons.
To describe the thin-section computed tomography (CT) findings of Sjogren syndrome accompanying pulmonary amyloidosis and lymphoproliferative disease and to compare these with histopathologic findings. ⋯ Sjogren syndrome accompanying pulmonary amyloidosis and lymphoproliferative disease manifests as multiple, large, thin-walled cysts; multiple nodules; parenchymal opacity; and bronchiectasis. These findings are caused by the interstitial or peribronchial infiltration of mixed amyloid and lymphoproliferative cells.
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J Comput Assist Tomogr · Nov 2004
Brain gamma-aminobutyric acid levels are decreased in patients with phantageusia and phantosmia demonstrated by magnetic resonance spectroscopy.
Olfactory and gustatory hallucinations (phantosmias and phantageusias, respectively) are sensory distortions that commonly follow losses of olfactory and gustatory acuity (hyposmia and hypogeusia, respectively). The biochemical basis of these hallucinations is unclear. Functional magnetic resonance imaging has been used previously to demonstrate widespread and robust central nervous system (CNS) activation to memories of these sensory distortions in patients with these symptoms. In this study, possible CNS mechanisms responsible for these distortions were evaluated using magnetic resonance spectroscopy, because this technique has been used to measure various CNS metabolites in patients with neurologic disorders. ⋯ These results indicate that decreased brain GABA levels can serve as biochemical markers of phantageusia and/or phantosmia in patients with these distortions and are the first biochemical changes in the CNS that reflect these sensory changes. After successful treatment of these distortions, CNS GABA levels increased to levels at or near normal, consistent with functional remission of these symptoms. These results substantiate a role for CNS GABA in the generation and inhibition of these sensory hallucinations. Although the underlying biochemical mechanism(s) for the generation of these decreased GABA levels are complex, because similar types of sensory hallucinations occur as auras or prodromata of epileptic seizure and migraine activity, these results suggest that there may be common biochemical changes among these disorders.
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J Comput Assist Tomogr · Sep 2004
ReviewAcute respiratory distress syndrome. Computed tomography findings and their applications to mechanical ventilation therapy.
In acute respiratory distress syndrome, computed tomography (CT) typically demonstrates symmetric ground-glass opacity and gravity-dependent consolidation when patients are positioned supine. Moreover, CT findings may vary according to the evolutional stage of the disease over time. The slope of the pressure-volume curve, which is a direct or indirect measure of lung recruitment rather than a measure of the characteristics of the respiratory mechanics of a portion of the aerated lung, indicates the potential for recruitment. ⋯ By partially relieving cardiac and abdominal compression, positioning patients in prone and semirecumbent positions may reopen dependent and caudal lung regions and improve gas exchange. The mean CT attenuation of a given region is equivalent to its aeration. Computed tomography, especially helical CT, may help to assess alveolar recruitment and lung overinflation by providing information on whole-lung attenuation.