Comparison of a 28-channel receive array coil and quadrature volume coil for morphologic imaging and T2 mapping of knee cartilage at 7T

作者：Chang Gregory^*; Wiggins Graham C; Xia Ding; Lattanzi Riccardo; Madelin Guillaume; Raya Jose G; Finnerty Matthew; Fujita Hiroyuki; Recht Michael P; Regatte Ravinder R

来源：Journal of Magnetic Resonance Imaging, 2012, 35(2): 441-448.

DOI：10.1002/jmri.23506

• cartilage
• magnetic resonance imaging
• multichannel coil
• T2 mapping
• ultrahigh field
• 7 Tesla

Purpose: To compare a new birdcage-transmit, 28-channel receive array (28-Ch) coil and a quadrature volume coil for 7T morphologic MRI and T2 mapping of knee cartilage.
Materials and Methods: The right knees of 10 healthy subjects were imaged on a 7T whole body magnetic resonance (MR) scanner using both coils. 3D fast low-angle shot (3D-FLASH) and multiecho spin-echo (MESE) sequences were implemented. Cartilage signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), thickness, and T2 values were assessed.
Results: SNR/CNR was 17%-400% greater for the 28-Ch compared to the quadrature coil (P <= 0.005). Bland-Altman plots show mean differences between measurements of tibial/femoral cartilage thickness and T2 values obtained with each coil to be small (-0.002 +/- 0.009 cm/0.003 +/- 0.011 cm) and large (-6.8 +/- 6.7 msec/-8.2 +/- 9.7 msec), respectively. For the 28-Ch coil, when parallel imaging with acceleration factors (AF) 2, 3, and 4 was performed SNR retained was: 62%-69%, 51%-55%, and 39%-45%.
Conclusion: A 28-Ch knee coil provides increased SNR/CNR for 7T cartilage morphologic imaging and T2 mapping. Coils should be switched with caution during clinical studies because T2 values may differ. The greater SNR of the 28-Ch coil could be used to perform parallel imaging with AF2 and obtain similar SNR as the quadrature coil.

• 出版日期2012-2