Comparison between 8- and 32-channel phased-array receive coils for in vivo hyperpolarized 13 C imaging of the human brain

Adam W Autry; Jeremy W Gordon; Lucas Carvajal; Azma Mareyam; Hsin-Yu Chen; Ilwoo Park; Daniele Mammoli; Maryam Vareth; Susan M Chang; Lawrence L Wald; Duan Xu; Daniel B Vigneron; Sarah J Nelson; Yan Li

doi:10.1002/mrm.27743

Comparison between 8- and 32-channel phased-array receive coils for in vivo hyperpolarized ¹³ C imaging of the human brain

Magn Reson Med. 2019 Aug;82(2):833-841. doi: 10.1002/mrm.27743. Epub 2019 Mar 29.

Authors

Adam W Autry¹, Jeremy W Gordon¹, Lucas Carvajal¹, Azma Mareyam², Hsin-Yu Chen¹, Ilwoo Park³, Daniele Mammoli¹, Maryam Vareth^{1

4}, Susan M Chang⁵, Lawrence L Wald^{2

6

7}, Duan Xu¹, Daniel B Vigneron¹, Sarah J Nelson^{1

8}, Yan Li¹

Affiliations

¹ Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco.
² Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts.
³ Department of Radiology, Chonnam National University Medical School and Hospital, Gwangju, Korea.
⁴ Berkeley Institute for Data Science (BIDS), University of California Berkeley, Berkeley.
⁵ Department of Neurological Surgery, University of California San Francisco, San Francisco, California.
⁶ Harvard Medical School, Boston, Massachusetts.
⁷ Harvard-MIT Health Sciences and Technology, MIT, Cambridge, Massachusetts.
⁸ Department of Bioengineering and Therapeutic Science, University of California San Francisco, San Francisco, California.

Abstract

Purpose: To compare the performance of an 8-channel surface coil/clamshell transmitter and 32-channel head array coil/birdcage transmitter for hyperpolarized ¹³ C brain metabolic imaging.

Methods: To determine the field homogeneity of the radiofrequency transmitters, B₁ + mapping was performed on an ethylene glycol head phantom and evaluated by means of the double angle method. Using a 3D echo-planar imaging sequence, coil sensitivity and noise-only phantom data were acquired with the 8- and 32-channel receiver arrays, and compared against data from the birdcage in transceiver mode. Multislice frequency-specific ¹³ C dynamic echo-planar imaging was performed on a patient with a brain tumor for each hardware configuration following injection of hyperpolarized [1-¹³ C]pyruvate. Signal-to-noise ratio (SNR) was evaluated from pre-whitened phantom and temporally summed patient data after coil combination based on optimal weights.

Results: The birdcage transmitter produced more uniform B₁ + compared with the clamshell: 0.07 versus 0.12 (fractional error). Phantom experiments conducted with matched lateral housing separation demonstrated 8- versus 32-channel mean transceiver-normalized SNR performance: 0.91 versus 0.97 at the head center; 6.67 versus 2.08 on the sides; 0.66 versus 2.73 at the anterior; and 0.67 versus 3.17 on the posterior aspect. While the 8-channel receiver array showed SNR benefits along lateral aspects, the 32-channel array exhibited greater coverage and a more uniform coil-combined profile. Temporally summed, parameter-normalized patient data showed SNR_mean,slice ratios (8-channel/32-channel) ranging 0.5-2.00 from apical to central brain. White matter lactate-to-pyruvate ratios were conserved across hardware: 0.45 ± 0.12 (8-channel) versus 0.43 ± 0.14 (32-channel).

Conclusion: The 8- and 32-channel hardware configurations each have advantages in particular brain anatomy.

Keywords: 32-channel; brain; carbon-13; echo-planar imaging; hyperpolarized; phased-array.

Publication types

Comparative Study
Research Support, N.I.H., Extramural

MeSH terms

Brain / diagnostic imaging*
Brain Neoplasms / diagnostic imaging
Equipment Design
Humans
Image Interpretation, Computer-Assisted / methods*
Magnetic Resonance Imaging / instrumentation*
Magnetic Resonance Imaging / methods*
Neuroimaging / methods
Phantoms, Imaging
Pyruvic Acid / metabolism
Signal-To-Noise Ratio

Substances

Pyruvic Acid

Abstract

Publication types

MeSH terms

Substances

Grants and funding