The Eastern North American Region of the International Biometric Society (ENAR) in Miami, Florida, March 2011
In fMRI, brain images are not measured instantaneously and a volume of images can take two seconds to acquire at a low 64x64 resolution. Significant effort has been put forth on many fronts to decrease image acquisition time including parallel imaging. In parallel imaging, sub-sampled spatial frequency points are measured in parallel and combined to form a single image. Measurement time is decreased at the expense of increased image reconstruction difficulty and time. One significant parallel imaging technique known as SENSE utilizes a complex-valued regression coefficient estimation process with transposes replaced by conjugate transposes. However, in SENSE the noise structure is not properly modeled. This work properly models the noise structure for complex-valued least squares regression. Differences in estimated images between SENSE and our new estimation procedure are evaluated.