3.0t mri scanner

This cross-sectional observational study was approved by the Institutional Review Board Ethics Committee of China-Japan Union Hospital (IRB No. 2016-nsfc028). All subjects provided signed informed consent prior to undergoing the MRI examination. All eligible volunteers were required to undergo MRI of the selected knee for review in the clinical imaging system using a Phillips 3.0-T MRI scanner. Volunteers were placed in the supine position with the knee fully extended. MRI scans were performed in coronal, sagittal, and horizontal position of the knee joint by 3-D dual-echo steady-state (3D-DESS), with a layer thickness of 0.5 mm. From January 2018 to January 2019, 40 (out of 98) volunteers were recruited from the community through use of research flyers. Eleven participants were later found to meet the exclusion criteria after taking MRI scans, and were therefore excluded from the present study. The inclusion criteria were: no knee joint pain or instability, skeletally mature, and healthy. The exclusion criteria were: congenital meniscus dysplasia, meniscus-related lesions, and preexisting cruciate ligament injuries. Finally, 29 subjects (10 men, 19 women, mean age 26 years [range, 20–33 years]) with 116 menisci (58 lateral and 58 medial) were included in the study (Figure 1).

Biodistribution of EuCF-DTG nanoparticles in rhesus macaques was determined using a Philips Achieva (Briarcliff Manor, NY, USA) 3.0T MRI scanner. T₂-weighted high-resolution imaging and T₂ mappings were obtained. High resolution T₂-weighted images were acquired using a turbo spin echo (TSE) sequence with 1428.6 ms repetition time, 90 ms echo time, 90° flip angle, 116 echo train length, 22 slices (3.5 mm slice thickness; 4.5 mm spacing between slices), 360 × 360 acquisition matrix, 360 × 360 mm FOV, 6 averages, for a total scan time of 31.42 min. A multi-echo TSE sequence was used for T₂ relaxation time mapping. Images were acquired with 2000 ms repetition time, 16 echoes (echo times TE_n = n x 6 ms; n = 1, …,16), 288 x 288 acquisition matrix, 360 × 360 mm FOV. This sequence was repeated to cover multiple coronal slices (12 slices for pre-injection and 16 slices for post-injection, 3.5 mm slice thickness, 4.5 mm spacing between slices). T₂ relaxation time maps were created using custom-developed computer programs using IDL programming language. ROI analysis was performed using ImageJ software.

Diffusion-weighted images (DWI) were acquired on a 3.0 T MRI scanner (Philips, Best, The Netherlands) using a 32-channel head coil and a single shot EPI with SENSE (parallel) acquisition. Sagittal diffusion slices were obtained using the following parameters: bvalue 1300s/mm², repetition time 7600 ms, echo time 65 ms, isotropic voxel size 2.5 × 2.5 × 2.5 mm, 60 non-collinear directions and 6 non-diffusion-weighted images. The scan acquisition time was 10:32 min.