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EFFECTS OF RF AMPLIFIER DISTORTION ON SELECTIVE EXCITATION AND THEIR CORRECTION BY PREWARPING MAGNETIC RESONANCE IN MEDICINE Chan, F., Pauly, J., Macovski, A. 1992; 23 (2): 224-238

Abstract

In a magnetic resonance imaging system, an RF power amplifier is employed to boost an RF pulse to sufficient strength to excite the nuclear spins in a subject. The nonideal behavior of this amplifier distorts a selective-excitation pulse, and this distortion in turn degrades the slice profile. We have found two types of nonideal behavior particularly troublesome: nonlinearity and incidental phase modulation. One of their effects is the introduction of an unwanted "skirt" in the out-of-slice region of a slice profile. We present an effective method of correction in which a selective-excitation pulse is prewarped to compensate for the distortion.

View details for Web of Science ID A1992HD21300003

View details for PubMedID 1549038