Iterative separation of transmit and receive phase contributions and B1(+)-based estimation of the specific absorption rate for transmit arrays.

Object: The specific absorption rate (SAR) can be determined from radiofrequency transmit fields measured via magnetic resonance imaging.

Materials And Methods: The proposed method estimates the SAR solely from the complex transmit field (B1(+)) by taking into account the particular properties of the electromagnetic field generated by an 8-channel transmit array. It is further based on an iterative consistency check between the measured B1(+) magnitude and an appropriate field estimate fulfilling Maxwell's equations.

Technical approaches to the optimisation of CT.

This paper reviews current technical approaches to the optimisation of CT practice, i.e. approaches to reduce patient dose to the necessary minimum.