Abstract: The invention relates to methods of diagnosing membrane fluidity-related disorders, or predispositions to membrane fluidity-related disorders, in a subject such as a human patient or an animal, e.g., an animal model of a human disorder. In general, the method includes acquiring a first proton relaxation measurement for a selected region of the brain in a magnetic resonance imaging (MRI) procedure; administering to the subject a challenge that alters physical properties or chemical composition of cell membranes in the brain of the subject; acquiring a second proton relaxation measurement for the selected region of the brain in an MRI procedure; and detecting any difference, e.g., an increase or decrease, between the first proton relaxation measurement and the second proton relaxation measurement, wherein a difference indicates a membrane fluidity-related disorder. The invention also includes methods of assessing the effectiveness of treatments or drugs, e.g.

Abstract: In a magnetic resonance imaging system in which the read and phase directions are rotated with respect to the orthogonal gradient coil directions, a gradient coil is driven to generate a gradient waveform having a segment, either sinusoidal or linear, that approximates the sum of the simultaneous non-zero components of the read and phase gradient waveforms in the direction of the gradient coil. Resonant circuits, each including a gradient coil, generate simultaneous periodic gradient coil waveforms in which the integral over each waveform period is non-zero. First and second capacitive elements in the resonant power supply are electrically connected to the gradient coil through a switch and a bridged network, respectively. The bridged network selectively provides current flow paths between the coil and either of the terminals of the second capacitive element.

Abstract: In a magnetic resonance imaging system in which the read and phase directions are rotated with respect to the orthogonal gradient coil directions, a gradient coil is driven to generate a gradient waveform having a segment, either sinusoidal or linear, that approximates the sum of the simultaneous non-zero components of the read and phase gradient waveforms in the direction of the gradient coil. Resonant circuits, each including a gradient coil, generate simultaneous periodic gradient coil waveforms in which the integral over each waveform period is non-zero. First and second capacitive elements in the resonant power supply are electrically connected to the gradient coil through a switch and a bridged network, respectively. The bridged network selectively provides current flow paths between the coil and either of the terminals of the second capacitive element.