Signa excite hd

MR scans were performed using a 1.5-T scanner (Signa Excite HD, General Electric, Milwaukee, WI, United States) with a head-and-neck combined coil. The axial and sagittal T1-weighted fast spin-echo (FSE) images, axial T2-weighted FSE images, and contrast-enhanced T1-weighted fat suppression images in the axial and coronal planes were obtained. All images were reviewed independently by two radiologists experienced in head and neck cancers, and differences were resolved by consensus. The final conclusions were confirmed by the multidisciplinary team of NPC at our center before treatment. Details regarding the diagnostic criteria for paranasal sinus invasion have been published previously (12 (link)).

Functional MRI data were collected from all PD patients in the morning. Brain functional MRI was performed using a 3.0 T scanner (Signa Excite HD GE Healthcare, Milwaukee, WI, USA) with an 8-channel head coil. During scanning, the subject was positioned supine in the framework of the scanner with foam padding to limit head movement and wore earplugs to reduce the impact of acoustic noise. All subjects were instructed to keep their eyes closed, to not think of anything in particular, and not fall asleep. The rs-fMRI data parameters were as follows: gradient-echo echo-planar imaging (GRE-EPI) sequence with repetition time (TR)/echo time (TE) = 2,000/30 ms, matrix = 64 × 64, 30 axial slices covering the entire brain, field of view = 240 × 240 mm, slice thickness = 4 mm, interslice space = 1 mm, NEX = 1, voxel size = 3.75 mm × 3.75 mm × 4 mm, time points = 186, and 30 axial slices covering the entire brain for a total of 5,580 images. Axial scans were acquired in parallel to the anterior-posterior commissure (AC-PC) line. High-resolution 3D T1-weighted anatomical images were obtained for coregistration with the functional data. A fast spoiled gradient recalled echo inversion recovery (FSPGRIR) sequence was used to acquire sagittal T1-weighted images with a TR/TE = 8.4/3.3 ms, matrix = 256 × 256, flip angle = 13°, slice thickness = 1 mm, and voxel size = 0.94 mm × 0.94 mm ×1 mm.

Preoperative MRI examinations were performed either on a 3.0 T (Verio, Siemens, Erlangen, Germany) or a 1.5 T MR scanner (Signa EXCITE HD, GE Healthcare, Milwaukee, WI, USA), both of which were equipped with 12‐channel head coils. Details of the MRI protocol were described in the Supplementary Materials. Four MRI sequences (T₁WI, T₁WI + C, T₂WI, and T₂-FLAIR) from each patient were aligned and resampled to the same geometry to T₁WI using 3D slicer (https://www.slicer.org/).

MR arthrography included intraarticular injection of the contrast agent under fluoroscopic guidance as well as subsequent MR imaging using a 1.5-T scanner (Signa Excite HD, GE Healthcare, Wauwatosa, WI, USA) and a dedicated shoulder array coil (8-channel shoulder array, GE Healthcare, Wauwatosa, WI, USA). The MR protocol was the established protocol for shoulder MR arthrography at our hospital. It consisted of a parasagittal T1-weighted fast spin echo (FSE) (repetition time/echo time (TR/TE), 595/8.3 ms; slice thickness, 3 mm; field of view (FOV), 140 mm; matrix, 416 x 256), a fat-suppressed parasagittal T2-weighted FSE (TR/TE, 4400/92 ms; slice thickness, 3 mm; FOV, 140 mm; matrix, 256 x 224), a paracoronal fat-suppressed T1-weighted FSE (TR/TE, 494/13 ms; slice thickness, 3 mm; FOV, 140 mm, matrix, 256 x 224), a paracoronal intermediate-weighted FSE (TR/TE, 2261/37 ms; slice thickness, 3 mm; FOV, 140 mm; matrix, 352 x 256), an axial intermediate-weighted FSE (TR/TE, 3229/36 ms; slice thickness, 3 mm; FOV, 140 mm; matrix, 256 x 224) and an axial three-dimensional gradient echo (TR/TE, 9.8/4.8 ms; slice thickness, 2 mm; FOV, 180 mm; matrix, 512 x 320). The scan time for each patient was approximately 24 minutes.