Abstract: A magnetic resonance imaging system erases magnetization components of at least a pair of adjacent regions sandwiching a region to be examined including a predetermined portion of interest of an object to be examined, and then selectively excites the region to be examined to obtain image information based on magnetic resonance data of the region to be examined. The magnetic resonance imaging system includes a controller for changing the polarity of a gradient field, which is applied simultaneously with a .pi./2 pulse, in units of the pair of adjacent regions when the magnetization components are to be erased.

Abstract: A coil system for magnetic resonance imaging in a magnetic resonance imaging system, used to transmit the excitation pulse and to receive the magnetic resonance signals, includes a first coil for transmitting a predetermined high-frequency pulse, second and third coils, arranged on a propagation path of the magnetic resonance signal at a position closer to the object to be examined than the first coil in directions orthogonal to each other, for receiving the magnetic resonance signals, and a pair of tuning elements, respectively provided in association with the second and third coils, for tuning the second and third coils to predetermined magnetic resonance signals. The tuning elements tune the second and third coils slightly offset from accurate tuning points so that voltage phases of the magnetic resonance signals received through the second and third coils coincide with each other.

Abstract: A magnetic resonance spectroscopic system for receiving a magnetic resonance signal from a localized area in a certain slice in a sample and obtaining a frequency spectrum of the magnetic resonance signal based on the received signal, includes control means for selectively exciting regions sandwiching a zone containing said localized area in one of x- and y-axis directions in said slice, thereafter applying a spoiler to eliminate lateral spin components from said regions, selectively exciting regions sandwiching a zone containing said localized area in the other of x- and y-axis directions in said slice, thereafter applying a spoiler to eliminate lateral spin components from said last-mentioned regions, and then exciting a zone containing said localized area in a z.sub.y -axis direction to extract a magnetic resonance signal of said localized area.

Abstract: The magnetic resonance imaging system applies a uniform static magnetic field and a gradient magnetic field to an object and further applies an excitation rotating magnetic field to cause magnetic resonance phenomena in the object, and detects the induced magnetic resonance signals and then obtains image data by these magnetic resonance signals. The system has a power controller for controlling the transmission power in a transmitter for transmitting the excitation rotating field. The system further has a transmission controller for controlling the power controller in response to the magnetic resonance signal which is received by the receiver from the object.

Abstract: In a magnetic resonance imaging system, a reference sample made of material including predetermined atomic nuclei to be tomographed is disposed on the side of an object under inspection in a tomographing field (an area to be tomographed) of an MR image. In collecting projection data by detecting the MR signal, the magnitude of the projection data on the reference sample is detected. A substantial gain of an MR signal amplifying section is adjusted according to the detected magnitude.

Abstract: Disclosed is a radiation detector provided at both ends with radiation source position detecting means each including three to five electrode plates in which a bias electrode plate centrally disposed has cover layers on both surfaces, and signal electrode plates disposed on both sides of the bias electrode plate each have a cover layer on only one surface farther from the bias electrode plate. Material of the cover layer has a smaller secondary electron emissive power than that of the material of the electrode plates with respect to incident radiation.