Reproducibility of quantitative cerebral T2 relaxometry, diffusion tensor imaging, and 1H magnetic resonance spectroscopy at 3.0 Tesla.

Objectives: The reproducibility of quantitative cerebral T2 relaxometry, diffusion tensor imaging, and H magnetic resonance (MR) spectroscopic imaging was assessed on a clinical 3.0 T MR system.

Materials And Methods: Repeated measurements in 10 healthy volunteers were used to establish the reproducibility of quantitative measures derived from different quantitative MR techniques, namely the T2 relaxation time, the apparent diffusion coefficient (ADC), the fractional anisotropy (FA), and metabolite concentrations of N-acetyl-aspartate (NAA), creatine (Cr), choline (Cho), and myo-inositol (mI).

1H MR spectroscopy of the brain: absolute quantification of metabolites.

Hydrogen 1 (1H) magnetic resonance (MR) spectroscopy enables noninvasive in vivo quantification of metabolite concentrations in the brain. Currently, metabolite concentrations are most often presented as ratios (eg, relative to creatine) rather than as absolute concentrations. Despite the success of this approach, it has recently been suggested that relative quantification may introduce substantial errors and can lead to misinterpretation of spectral data and to erroneous metabolite values.

Functional MRI reveals declined prefrontal cortex activation in patients with epilepsy on topiramate therapy.

Functional magnetic resonance imaging of covert word generation was used to examine brain activation abnormalities associated with topiramate-induced cognitive language impairment in patients with epilepsy. Compared with a control epilepsy group, in the topiramate-treated group, there was significantly less activation in the language-mediating regions of the prefrontal cortex; the topiramate group also had significantly lower neuropsychological language scores. These findings suggest that topiramate has a critical effect on the cerebral neural systems that mediate expressive language.