Clinical MRI sequences for imaging near metallic implants are mainly multi-spectral approaches, with fast spin-echo acquisitions to achieve clinically relevant scan times. Due to the large bandwidths necessary for refocusing all off-resonance spins near metallic implants, usually the refocusing pulse flip angles must be limited to a sub-optimal value to permit a safe specific absorption rate. Here, a low peak amplitude, radiofrequency refocused sequence is used to limit energy deposition. Reversed encoding is employed, where two acquisitions are collected with opposite frequency-encoding gradient polarity. An estimate of the displacement field is found using a B-spline basis and the magnitude images.
How to access this content:
For one year after publication, abstracts and videos are only open to registrants of this annual meeting. Registrants should use their existing login information. Non-registrant access can be purchased via the ISMRM E-Library.
After one year, current ISMRM & ISMRT members get free access to both the abstracts and videos. Non-members and non-registrants must purchase access via the ISMRM E-Library.
After two years, the meeting proceedings (abstracts) are opened to the public and require no login information. Videos remain behind password for access by members, registrants and E-Library customers.
Keywords