Magnetic Susceptibility Effects in High Field MRI

Abstract

In high-magnetic-field MRI, both valuable image contrast and undesirable artifacts associated with the magnetic susceptibility effects are significantly increased. The magnetic field distortion in and by the human body is described with computer modeling methods in the human head. The manifestations of the resultant image artifacts include signal loss, blurring, and geometric distortion and are dependent on imaging methods. The treatments of the artifacts in the specific imaging sequences are described and demonstrated with human studies at 3 and 7 Tesla and animal studies at field strengths as high as 14 Tesla. With these in vivo studies, the enhanced image contrast produced by the increased field strength and the improved image quality by the artifact reduction methods provide strong and stimulating evidence for exciting potential scientific applications of high field MRI.