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Used MRI (used + mri)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Insights into the acute cerebral metabolic changes associated with childhood diabetes

DIABETIC MEDICINE, Issue 5 2005
F. J. Cameron
Abstract Aims Type 1 diabetes is a prevalent chronic disease in childhood with the commonest single cause of death being cerebral oedema in the context of diabetic ketoacidosis (DKA). The nature of the alterations in cerebral metabolism that may result in vulnerability to neuronal injury remains unknown. The aim of this study was to analyse the magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) brain data from eight children with diabetes following acute presentation with hyperglycaemia with or without ketoacidosis, to determine the nature and timing of any alterations in cerebral structure and metabolism. Methods This study used MRI and MRS to investigate regional cerebral abnormalities in a small series of diabetic patients with and without DKA. Changes were compared with the clinical and biochemical features of the patients studied. Results Our small series of patients all demonstrated abnormal signal changes in the frontal region on fluid attenuated inversion recovery (FLAIR) MR imaging, suggestive of oedema, and spectroscopic abnormalities of increased taurine, myoinositol and glucose levels. The MR abnormalities varied in severity but did not correlate with any clinical or biochemical parameters. Conclusions These changes indicate that many diabetic children, particularly at presentation, may have alterations in cerebral metabolism with implications for the pathogenesis and treatment of the cerebral complications of DKA. In addition, our findings suggest that increased taurine may be one of the important differentiating factors in the response of the brain of diabetic children to DKA that may reflect an increase in their vulnerability to cerebral oedema compared with diabetic adults. [source]

Effect of the preliminary hydration on gastric emptying time for water in healthy volunteers

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2009
T. UMENAI
Background: International guidelines allow healthy patients to drink clear liquid up to 2 h before general anesthesia. Recently, MRI measurements have been used for tracking gastric volume in humans. Hence, we used MRI to examine the gastric emptying rate of water in healthy volunteers with or without prior water loading. Methods: Fifteen healthy volunteers were enrolled. The participants had MRI examinations on separate days under two different protocols: The preliminary hydration protocol (group H) and the water restriction protocol (group R). After the intake of water, MR imaging was performed every 10 min for 60 min. The gastric content was outlined as area of interest (AOI), and the AOI area of each slice was summated to calculate the volume of gastric contents. Results: The 50% reduction time of gastric volume in group R and group H was 18±9 and 16±8 min (mean±SD), respectively. There were no significant changes between the two groups. Conclusion: The gastric emptying time for water evaluated with MRI was not affected by preliminary hydration, which shows the safety of repeated oral hydrations in the pre-operative period. [source]

Measuring Brain Atrophy in Multiple Sclerosis

JOURNAL OF NEUROIMAGING, Issue 2007
Nicola De Stefano MD
ABSTRACT The last decade has seen the development of methods that use conventional magnetic resonance imaging (MRI) to provide sensitive and reproducible assessments of brain volumes. This has increased the interest in brain atrophy measurement as a reliable indicator of disease progression in many neurological disorders, including multiple sclerosis (MS). After a brief introduction in which we discuss the most commonly used methods for assessing brain atrophy, we will review the most relevant MS studies that have used MRI-based quantitative measures of brain atrophy, the clinical importance of these results, and the potential for future application of these measures to understand MS pathology and progression. Despite the number of issues that still need to be solved, the measurement of brain atrophy by MRI is sufficiently precise and accurate. It represents one of most promising in vivo measures of neuroaxonal degeneration in MS, and it should be used extensively in the future to assess and monitor pathological evolution and treatment efficacy in this disease. [source]

MRI monitoring of focal cerebral ischemia in peroxisome proliferator-activated receptor (PPAR)-deficient mice

NMR IN BIOMEDICINE, Issue 3 2007
Jean-Baptiste Pialat
Abstract Peroxisome proliferator-activated receptors (PPARs) are a potential target for neuroprotection in focal ischemic stroke. These nuclear receptors have major effects in lipid metabolism, but they are also involved in inflammatory processes. Three PPAR isotypes have been identified: ,, , (or ,) and ,. The development of PPAR transgenic mice offers a promising tool for prospective therapeutic studies. This study used MRI to assess the role of PPAR, and PPAR, in the development of stroke. Permanent middle cerebral artery occlusion induced focal ischemia in wild-type, PPAR, -null mice and PPAR, -null mice. T2 -weighted MRI was performed with a 7 T MRI scan on day 0, 1, 3, 7 and 14 to monitor lesion growth in the various genotypes. General Linear Model statistical analysis found a significant difference in lesion volume between wild-type and PPAR-null mice for both , and , isotypes. These data validate high-resolution MRI for monitoring cerebral ischemic lesions, and confirm the neuroprotective role of PPAR, and PPAR, in the brain. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Quantitative MRI reveals aging-associated T2 changes in mouse models of Alzheimer's disease

NMR IN BIOMEDICINE, Issue 3 2007
M. F. Falangola
Abstract In this study, we used MRI to analyze quantitative parametric maps of transverse (T2) relaxation times in a longitudinal study of transgenic mice expressing mutant forms of amyloid precursor protein (APP), presenilin (PS1), or both (PS/APP), modeling aspects of Alzheimer's disease (AD). The main goal was to characterize the effects of progressive , -amyloid accumulation and deposition on the biophysical environment of water and to investigate if these measurements would provide early indirect evidence of AD pathological changes in the brains of these mice. Our results demonstrate that at an early age before , -amyloid deposition, only PS/APP mice show a reduced T2 in the hippocampus and cortex compared with wild-type non-transgenic (NTg) controls, whereas a statistically significant within-group aging-associated decrease in T2 values is seen in the cortex and hippocampus of all three transgenic genotypes (APP, PS/APP, and PS) but not in the NTg controls. In addition, for animals older than 12 months, we confirmed our previous report that only the two genotypes that form amyloid plaques (APP and PS/APP) have significantly reduced T2 values compared with NTg controls. Thus, T2 changes in these AD models can precede amyloid deposition or even occur in AD models that do not deposit , -amyloid (PS mice), but are intensified in the presence of amyloid deposition. Copyright © 2007 John Wiley & Sons, Ltd. [source]