Abstract #0350

Butler matrix transmit channel compression in pTx: a SAR-aware study.

Mihir Rajendra Pendse¹, Riccardo Stara^1,2,3, Gianluigi Tiberi⁴, Alessandra Retico², Michela Tosetti⁵, and Brian Rutt¹

¹Stanford University, Stanford, CA, United States, ²Istituto Nazionale di Fisica Nucleare (Pisa), Pisa, Italy, ³Universita' di Pisa, Pisa, Italy, ⁴IMAGO7, Pisa, Italy, ⁵ISRCC Stella maris, Calambrone (Pisa), Italy

The use of a Butler matrix in pTx is thought to allow transmit channel compression by a factor of 2 or more compared to direct drive, while maintaining similar flip angle control. However, the SAR-related consequences of this compression strategy are relatively unexplored. Using a SAR-aware pTx design method (IMPULSE), we demonstrate that excellent flip angle uniformity is indeed possible using only 2 or 4 Butler modes compared to 8 direct drive channels; however, this comes at the expense of increased SAR. We also present a generalized strategy for selecting the optimal subset of Butler modes, i.e. the subset that provides adequate flip angle control at minimum SAR.

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.

Click here for more information on becoming a member.