Signatm architect

All patients underwent MRI scanning of the sacroiliac joints in the supine position using a 3.0 T superconducting MR scanner (SignaTM Architect, GE Healthcare, Milwaukee, WI) with an anterior 30-channel and posterior 40-channel adaptive image receive (AIR) radiofrequency coil. The routine SIJ MRI examination consisted of T2-weighted fat-suppressed turbo spin echo sequence (T2-FS), T1-weighted images sequence (T1WI), T1-weighted images with fat saturation (T1-FS) sequence in a semi-coronal orientation and T2-FS sequences in a semi-axial orientation for the SIJ were available. The chemical shift-encoded sequence in the semi-coronal orientation of the SIJ were acquired under the following scan parameters: TR=12.1 ms. TE=6 ms; bandwidth = 142.86 KHZ; echo train length (ETL) = 3; flip angle=5;number of excitations (NEX)=1; matrix 256x256; 24 sections at a thickness of 4 mm; and scan time= 2 minutes 40 seconds.

All patients underwent MRI scanning of the sacroiliac joints in the supine position using a 3.0 T superconducting MR scanner (SignaTM Architect, GE Healthcare, Milwaukee, WI) with an anterior 30-channel and posterior 40-channel adaptive image receive (AIR) radiofrequency coil. The routine SIJ MRI examination consisted of T2-weighted fat-suppressed turbo spin echo (T2-FS) sequence, T1-weighted images (T1WI) sequence, T1-weighted images with fat saturation (T1-FS) sequence in a semi-coronal orientation and T2-FS sequences in a semi-axial orientation for the SIJ were available. In addition, a ZTE sequence and a LAVA-Flex sequence were performed. Scan parameters of each MRI sequence could be seen in Table 1.

MRI was performed using a 3T system (Signa^TM Architect; GE Healthcare, Milwaukee, WI, USA) with a 48-channel head coil. In addition to 3D T1WI, routine brain MRI (axial T2-weighted imaging, fluid-attenuated inversion recovery, diffusion-weighted imaging, and 3D multi-echo gradient echo [susceptibility-weighted angiography]) was performed in all patients. Meanwhile, 3D T1WI (BRAVO) scans were obtained with sagittal planes covering the whole brain and using the following parameters: repetition time/echo time, 7.0/2.8; section thickness, 1.0 mm; matrix, 210 × 210 mm; flip angle, 12.0; field of view, 210 × 210 mm; parallel imaging acceleration factor, phase 2; bandwidth, 31.25; and acquisition time, 3 min 4 s.