Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Pulse sequence diagram of the proposed external calibration acquisition. The maximum gradient amplitude during RF excitation is limited to a maximum value of GRF to prevent slice-selectivity artifacts and signal excitation loss near metallic implants. Immediately after excitation, gradients are ramped, allowing calibration acquisitions with ultrashort echo times.
