RASER (rapid acquisition with sequential
excitation and refocusing) is an ultrafast imaging technique based on
spatiotemporal encoding (SPEN). The excitation with a chirp-pulse with a low bandwidth-time product (R-value) introduces blurring in the SPEN
dimension. Superresolution (SR) which removes the blurring fails as a result of
the spatially varying B1-phase
produced by radio-frequency coils at ultrahigh fields. A novel iterative
phase-correction of the SR-algorithm is presented. It is shown that the spatial
resolution and the SNR of blurred RASER images acquired at 7 T are significantly
improved employing phase-corrected SR.
