Multiple imaging with improved signal-to-noise ratio

Abstract

Gradients are caused across a magnetic field in an image region by gradient field coils (22). A transmitter (30) causes an RF antenna (32) to generate excitation pulses to excite selected dipoles from the image region to resonance. A first receiving coil (50) and a second receiving coil (52) are disposed along the gradient to receive magnetic resonance signals from first and second fields of view (102, 104) within the image region. First and second phase sensitive detectors (70, 72) demodulate the magnetic resonance signals at different frequencies. Analog-to-digital converters (80, 82, 84, 86) digitize magnetic resonance signal components from the phase sensitive detectors to provide digital data for reconstruction by Fourier transform circuits (90, 92). By interconnecting each of the receiving coils with one of the phase sensitive detectors, two of the analog-to-digital converters, and one of the Fourier transform circuits, two images each corresponding to one of the fields of view can be generated concurrently. Alternately, a single receiving coil may provide a single magnetic resonance signal which is split among the phase sensitive detectors and the analog-to-digital converters. In this manner, parallel and processing channels are provided to reduce the noise by the square root of two.