University of California

Zang-Hee Cho

Edward K Wong

Richard M Friedenberg

William E Bunny

Monte S Buchsbaum

Extremely non-homogenous high but extremely intense high fringe magnetic fields are purposefully (and even advantageously) utilized for magnetic resonance imaging (including localization and spectroscopy) so as to better obtain advantages typically associated with ultra high field MRI. Static magnetic field gradients inherently included in such fringe fields are actively utilized in conjunction with suitable NMR RF nutation pulses so as to achieve volume-selective NMR data acquisition. Special arrangements of static electromagnets, magnetic gradient coils and/or RF coils may be used in conjunction with novel RF/gradient pulse sequences so as to elicit and acquire suitable MRI data.

Fringe field MRI

A greatly reduced number of scintillation cyrstal/PMT gamma ray detectors are employed in a ring array about a PET image volume. Because of the relatively small number of such detectors, the complexity and expense of associated electronic signal processing channels is greatly reduced (even if each such channel is provided with sophisticated time of flight capabilities). Similarly, because relatively fewer crystals are employed, it becomes possible to use much larger and faster response time scintillation crystals so as to greatly increase gamma ray detection efficiency and scatter rejection while also permitting the electronic circuits to better reject random events and to provide effective time of flight image data filtering. By providing successively offset collimation apertures for each successive detector of the ring array and by rotating the array 360 degrees through a large number of successive view angle positions, it is nevertheless possible to acquire extremely high resolution image data with a greatly reduced system cost. A multiple aperture embodiment provides improved sensitivity by using associated light collimators and photodiodes in conjunction with slow coincidence steering circuits.

Growing community of inventors

Corona Del Mar, CA, United States of America

Zang-Hee Cho