Work

A fast, analytically based method to optimize local transmit efficiency for a transmit array

Year: 2013

Type: article

Abstract: PURPOSE: To develop an analytically based algorithm for rapid optimization of the local radiofrequency magnetic (B1+) field intensity for a given radiofrequency power through a transmit array. The analytical nature of the method will yield insight to optimization requirements and provides a valuable reference for numerically based searches. METHODS: With the knowledge of the B1+ field distribution generated by each single coil of the array, both the phases and the amplitudes of each coil current are optimized to maximize the magnitude of the B1+ field in a specific location of the body per unit of power transmitted through the array and, consequently, minimizing the whole body specific absorption rate for a given pulse sequence. RESULTS: Simulations considering the human body show that the proposed method can reduce the whole-body specific absorption rate for a given B1+ magnitude at the location of interest by a factor of about 6.3 compared to the classic birdcage current configuration, and by a factor of 3.2 compared to phase-only shimming in a case with significant coupling between the elements of the array. CONCLUSION: The proposed method can rapidly provide valuable information pertinent to the optimization of field distributions from transmit arrays.

Source: Magnetic Resonance in Medicine

DOI: 10.1002/mrm.24653

Authors: Giuseppe Carluccio, Christopher M. Collins, Danilo Erricolo

Institutions: NYU Langone Health, New York University, University of Illinois Chicago

Language: English

Topic: Advanced MRI Techniques and Applications

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: green

Funders: National Institutes of Health, National Institute of Biomedical Imaging and Bioengineering