Table 2.

Magnetic resonance imaging sequences and parameters at the four study sites

	Machine and coil	T1-weighted sagittal	Proton density-weighted sagittal
Hobart (Note: used two different MRI scanners. Patients had their follow-up scans on the same scanner in which they had their screening scan).	1.5 T whole-body MR unit (GE Optima 450 W, Milwaukee, USA), using a dedicated 8-channel knee coil 1.5 T whole-body MR unit (Siemens, Espree), using a dedicated 15-channel knee coil	T1-weighted fat-saturated 3D gradient-recalled acquisition; flip angle 30 degrees; repetition time 38 msec; echo time 3 msec; field of view 16 cm; 512 × 512 matrix; 1 excitation; slice thickness 1.5 mm T1-weighted fat-saturated 3D gradient-recalled acquisition; flip angle 30 degrees; repetition time 31 msec; echo time 6.8 msec; field of view 16 cm; 512 × 512 matrix; 1 excitation; slice thickness 1.5 mm	Proton density fat-saturated 2D fast spin echo sequence; flip angle 150 degrees; repetition time 3800 msec; echo time 35 msec; field of view 16 cm; 512 × 512 matrix; 3 excitations; slice thickness 3 mm Proton density fat-saturated 2D fast spin echo sequence; flip angle 150 degrees; repetition time 3830 msec; echo time 39 msec; field of view 16 cm; 512 × 512 matrix; 3 excitations; slice thickness 3 mm
Melbourne	3.0 T whole-body MR unit (Philips, Achieva, Medical Systems), using a commercial 16-channel transmit receive knee coil	T1-weighted fat-saturated 3D gradient-recalled acquisition; flip angle 15 degrees; repetition time 25.9 msec; echo time 9.2 msec; field of view 16 cm; 320 × 320 matrix; slice thickness 0.5 mm	Proton density fat-saturated 2D fast spin echo sequence; flip angle 90 degrees; repetition time 3814 msec; echo time 25 msec; field of view 16 cm; 720 × 720 matrix; slice thickness 2.5 mm
Sydney	1.5 T whole-body MR unit (Siemens, Aera) using a dedicated 15-channel transmit-receive knee coil	T1-weighted fat-saturated 3D gradient-recalled acquisition; flip angle 30 degrees, repetition time 31 msec; echo time 6.8 msec; field of view 16 cm; 512 × 512 matrix; slice thickness 1.5 mm	Proton density fat-saturated 2D fast spin echo sequence; flip angle 150 degrees; repetition time 3830 msec; echo time 39 msec; field of view 16 cm; 512 × 512 matrix; slice thickness 3 mm
Adelaide	1.5 T whole-body MR unit (Siemens, Aera) using a dedicated 15-channel transmit-receive knee coil	T1-weighted fat-saturated 3D gradient-recalled acquisition; flip angle 30 degrees, repetition time 14.7 msec; echo time 6.74 msec; field of view 16 cm; 448 × 448 matrix; 1 excitation; slice thickness 1.5 mm	Proton density fat-saturated 2D fast spin echo sequence; flip angle 180 degrees; repetition time 3200 msec; echo time 39 msec; field of view 16 cm; 320 × 320 matrix; 1 excitation; slice thickness 3 mm