Systems and Methods for Improved and Efficient Determination of the Specific Absorption Rate (SAR) in MRI

摘要

Magnetic resonance imaging (MRI) systems and methods to effect improved and more efficient determination of the specific absorption rate (SAR) are described. The SAR is calculated based upon a derived relationship between a body surface area (BSA) and a portion of the total radio frequency (RF) energy delivered to RF transmit coil that is deposited in the imaging subject, and the scanning is controlled in accordance with the calculated SAR.

主权项

1. A magnetic resonance imaging (MRI) system comprising:
an MRI gantry having components including a static magnetic field coil, gradient magnetic field coils, at least one radio frequency (RF) coil configured to transmit RF nuclear magnetic resonance (NMR) RF excitation pulses into an imaging volume and to receive NMR RF signals from a patient located in the imaging volume; and one or more computer control circuits configured and connected to control said gantry components to perform operations comprising:
receive one or more input parameters including a weight for the patient;calculate a body surface area (BSA) for the patient based upon the received one or more input parameters;monitor total power delivered to the at least one RF coil;determine a power ratio, based upon the calculated BSA, between total power and power deposited in the patient;calculate a specific absorption rate (SAR) based upon at least the determined power ratio and the total power; andcausing the one or more control circuits to control the transmission of RF signals based upon the calculated SAR.