Reduced FOV, Reference Scans, Gradient Pre-Emphasis

This lecture focuses on three pulse sequence strategies to increase spatial resolution, accelerate acquisition, and improve image quality while reducing artifacts. First, strategies for reducing the field-of-view (FOV) are described using examples of spatial saturation, multi-dimensional RF excitation, and selective RF refocusing. Second, reference scans are presented for measuring errors in k-space and enabling various phase corrections in echo-train pulse sequences. Third, gradient pre-emphasis is discussed as an effective method to reduce the adverse effects caused by eddy currents in a variety of pulse sequences. Although these three topics may appear isolated, together they reflect a central theme of how to improve image quality and/or speed while avoiding artifacts.