Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Jul 2006
Prospective longitudinal proton magnetic resonance spectroscopic imaging in adult traumatic brain injury.
To investigate whether longitudinal magnetic resonance proton spectroscopic imaging (MRSI) demonstrates regional metabolite abnormalities after traumatic brain injury (TBI) that predict long-term neurologic outcome. ⋯ The NAA/Cr ratio from the corpus callosum was most useful for outcome prediction. Chronic alterations of metabolite ratios are likely due to neuronal loss and glial proliferation long after injury.
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To demonstrate the feasibility of in vivo calf muscle fiber tracking in human subjects. ⋯ The study clearly shows that in vivo fiber tracking of muscle fibers is feasible and could potentially be applied to study muscle structure function relationships.
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J Magn Reson Imaging · Jul 2006
Evaluation of the articular cartilage of the knee joint with vastly undersampled isotropic projection reconstruction steady-state free precession imaging.
To determine the feasibility of the vastly undersampled isotropic projection reconstruction steady-state free precession (VIPR-SSFP) sequence for evaluating the articular cartilage of the knee joint. ⋯ VIPR-SSFP images had high cartilage signal-to-noise efficiency and high CNR between cartilage and adjacent synovial fluid and subchondral bone; therefore, the sequence is well suited for evaluating the articular cartilage of the knee joint.
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J Magn Reson Imaging · Jul 2006
Real-time monitoring of radiofrequency ablation of rabbit liver by respiratory-gated quantitative temperature MRI.
To evaluate the feasibility and precision of magnetic resonance imaging (MRI) thermometry for monitoring radiofrequency (RF) liver ablation in vivo and predicting the size of the ablation zone. ⋯ Quantitative temperature MRI during RF ablation is feasible and offered a precise indication of the ablation zone size in this preclinical study based on the lethal dose threshold.
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J Magn Reson Imaging · Jun 2006
ReviewDesign and analysis of fMRI studies with neurologically impaired patients.
Functional neuroimaging can be used to characterize two types of abnormality in patients with neurological deficits: abnormal functional segregation and abnormal functional integration. In this paper we consider the factors that influence the experimental design, analysis, and interpretation of such studies. With respect to experimental design, we emphasize that: 1) task selection is constrained to tasks the patient is able to perform correctly, and 2) the most sensitive designs entail presenting stimuli of the same type close together. ⋯ At the second level (between subjects), inference should be based on between-subjects variance. Provided that these and other constraints are met, deficits in functional segregation are indicated when activation in one or a set of regions is higher or lower in patients relative to control subjects. In contrast, deficits in functional integration are implied when the influence of one brain region on another is stronger or weaker in patients relative to control subjects.