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

✍ Scribed by Gregory Chang; Graham C. Wiggins; Ding Xia; Riccardo Lattanzi; Guillaume Madelin; Jose G. Raya; Matthew Finnerty; Hiroyuki Fujita; Michael P. Recht; Ravinder R. Regatte

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 835 KB
• Volume: 35
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.23506

✦ Synopsis

Abstract

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. J. Magn. Reson. Imaging 2012;441‐448. © 2011 Wiley Periodicals, Inc.