Dataset Information

Introduction of the snake antenna array: Geometry optimization of a sinusoidal dipole antenna for 10.5T body imaging with lower peak SAR.

ABSTRACT:

Purpose

To improve imaging performance for body MRI with a local transmit array at 10.5T, the geometry of a dipole antenna was optimized to achieve lower peak specific absorption rate (SAR) levels and a more uniform transmit profile.

Methods

Electromagnetic simulations on a phantom were used to evaluate the SAR and B1+ -performance of different dipole antenna geometries. The best performing antenna (the snake antenna) was simulated on human models in a 12-channel array configuration for safety assessment and for comparison to a previous antenna design. This 12-channel array was constructed after which electromagnetic simulations were validated by B1+ -maps and temperature measurements. After obtaining approval by the Food and Drug Administration to scan with the snake antenna array, in vivo imaging was performed on 2 volunteers.

Results

Simulation results on a phantom indicate a lower SAR and a higher transmit efficiency for the snake antenna compared to the fractionated dipole array. Similar results are found on a human body model: when comparing the trade-off between uniformity and peak SAR, the snake antenna performs better for all imaging targets. Simulations and measurements are in good agreement. Preliminary imaging result were acquired in 2 volunteers with the 12-channel snake antenna array.

Conclusion

By optimizing the geometry of a dipole antenna, peak SAR levels were lowered while achieving a more uniform transmit field as demonstrated in simulations on a phantom and a human body model. The array was constructed, validated, and successfully used to image 2 individuals at 10.5T.

SUBMITTER: Steensma B

PROVIDER: S-EPMC7496175 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Introduction of the snake antenna array: Geometry optimization of a sinusoidal dipole antenna for 10.5T body imaging with lower peak SAR.

Steensma Bart B van de Moortele Pierre-Francois PF Ertürk Arcan A Grant Andrea A Adriany Gregor G Luijten Peter P Klomp Dennis D van den Berg Nico N Metzger Gregory G Raaijmakers Alexander A

Magnetic resonance in medicine 20200505 5

<h4>Purpose</h4>To improve imaging performance for body MRI with a local transmit array at 10.5T, the geometry of a dipole antenna was optimized to achieve lower peak specific absorption rate (SAR) levels and a more uniform transmit profile.<h4>Methods</h4>Electromagnetic simulations on a phantom were used to evaluate the SAR and B 1 + -performance of different dipole antenna geometries. The best performing antenna (the snake antenna) was simulated on human models in a 12-channel array configur ...[more]

PMID: 32367560

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Dataset Information

Introduction of the snake antenna array: Geometry optimization of a sinusoidal dipole antenna for 10.5T body imaging with lower peak SAR.

Purpose

Methods

Results

Conclusion

Publications

Introduction of the snake antenna array: Geometry optimization of a sinusoidal dipole antenna for 10.5T body imaging with lower peak SAR.

Similar Datasets

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