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Eur Radiol (2012) 22:18521859 DOI 10.1007/s00330-012-2450-1
MUSCULOSKELETAL
Magnetic resonance imaging of the knee at 3 and 7 Tesla: a comparison using dedicated multi-channel coils and optimised 2D and 3D protocols
Goetz H. Welsch & Vladimir Juras & Pavol Szomolanyi &
Tallal C. Mamisch & Peter Baer &
Claudia Kronnerwetter & Matthias Blanke &
Hiroyuki Fujita & Siegfried Trattnig
Received: 4 November 2011 /Accepted: 20 February 2012 /Published online: 27 April 2012 # European Society of Radiology 2012
AbstractObjectives To show the feasibility and possible superiority of two 7 Tesla knee protocols (7 T high resolution and 7 T quick) using a new 28-channel knee coil compared to an optimised 3 T knee protocol using an 8-channel knee coil.
Methods The study was approved by the ethics committee. Both 3 T and 7 T MRI of the knee were performed in 10 healthy volunteers (29.67.9 years), with two 2D sequences (PD-TSE and T1-SE) and three isotropic 3D sequences (TRUFI, FLASH and PD-TSE SPACE). Quantitative contrast-to-noise ratio (CNR) and qualitative evaluations
were performed by different readers, and intra- and inter-rater agreement was assessed.
Results The signal-to-noise ratio (SNR) as well as the CNR values for cartilagebone, cartilagefluid, cartilagemenisci and meniscifluid were, in most cases, higher at 7 T compared to 3 T, and the 7 T quick measurement was slightly superior compared to the 7 T high-resolution measurement. The results of the subjective qualitative analysis were higher for the 7 T measurements compared to the 3 T measurements. Inter- and intra-observer reliability was high (0.8840.999). Conclusions Through higher field strength and an optimal coil, resolution at 7 T can be increased and acquisition time can be reduced, with superior quantitative and comparable qualitative results compared to 3 T.
Key Points 7-Tesla MRI using a dedicated 28-channel knee coil provides high quality. Isotropic 3D-MR sequences benefit more from ultra-highfield than basic 2D sequences. At 7 T high resolution and short MR acquisition are possible. Dedicated coils ensure the clinical applicability of musculoskeletal MRI at ultra-high-field.
Keywords MRI . 3 Tesla . 7 Tesla . Cartilage . Isotropic
Introduction
Significant progress has been made in magnetic resonance imaging (MRI) of the musculoskeletal system at high field(3 T), and, recently, at ultra-high field (above 3 T) [13]. Since the signal...