3.0 tesla mr scanner

A 3.0 Tesla MR scanner (Siemens, Erlangen, Germany) was used with a custom-built rodent receiver coil (Chenguang Med Tech, Shanghai, China). Axial turbo spin echo fat-suppressed(FS) T₂WI were obtained with a bandwidth of 203 Hz, slice thickness of 1.5 mm, Repetion Time (TR)/Echo Time(TE) of 4690/85 ms, FOV of 60×60 mm, matrix of 256×256, and a voxel size of 0.2×0.2×1.5 mm³. The total acquisition time was about 3.5 min. Four weeks after surgery, the experimental mice (n = 3) were intravenously injected with HA-Fe₃O₄ NPs via the tail vein, anesthetized with pentobarbital sodium (30 mg/kg), and followed by static MR scanning. MR images were obtained both before and after administration of the HA-Fe₃O₄ NPs (Fe mass  = 2.0 mg/mouse) at the time points of 0.25, 0.5, 1 and 2 h post injection. Values of signal intensity in the cystic wall of endometriotic lesion on T₂WI at each time point were measured and recorded.

The patients and healthy controls underwent DTI and NODDI using a 3.0-Tesla MR scanner (Siemens, Erlangen, Germany) with a 32-channel head coil. All participants were instructed to close their eyes and not fall asleep. Structural imaging, including T1-weighted volume using magnetization-prepared rapid acquisition with gradient echo and T2 (fluid-attenuated inversion recovery), was performed. For T1-weighted imaging, the following parameters were used: repetition time (TR)/echo time (TE) = 2300/2.32 ms, 192 slices, and slice thickness = 0.9 mm. The following single-shot echo planar imaging parameters were used for diffusion-weighted acquisition: TR/TE = 7500/95 ms; matrix size = 128 × 128; 50 axial slices; slice thickness = 3 mm with no gap; field of view = 230 × 230 mm; 65 axial slices; number of excitations = 1; generalized autocalibrating partially parallel acquisitions (GRAPPA) factor = 2; 30 non-collinear axes; and b values of 0, 1000, and 2000 s/mm². The FA, MD, AD, RD, Fiso, ODI, and Ficvf in the whole brain were analyzed using tract-based spatial statistics (TBSS). The region of interest (ROI) was placed on the corpus callosum. All MR images were examined during the interictal phase of the migraine.

Various concentrations of the PEG–PAA modified NaGdF₄:Yb,Er@NaDyF₄ and NaGdF₄:Yb,Er@NaDyF₄@NaDyF₄ nanoparticles dispersed in deionized water were prepared, and their T₁ weighted MR images were acquired on a Siemens 3.0 Tesla MR scanner using the inversion recovery (IR) sequence. The imaging parameters were as follows: repetition time (T_R) = 4000 ms, echo time (T_E) = 10.88 ms, and a series of inversion times (T_I) between 50 and 3500 ms were employed. The field of view (FOV) = 220 × 220 mm². Then the T₁ values of each sample at different concentrations were calculated on a workstation to obtain the relaxivity.

HDPSCs labeled with different concentrations of MIRB (12.5 μg/mL–100 μg/mL) were harvested and counted with a hemacytometer. 1 × 10⁵ or 1 × 10⁶ cells from each group were transferred into 1.5-ml microcentrifuge tubes (Eppendorf, Westbury, NY, USA). After being centrifuged at 150 ×g for 5 min, the hDPSCs pellets at the bottom of each tube were fixed with 4% PFA for 15 min and then the PFA was discarded. Then 1% (w/v) agarose solution was added into each tube which was kept at 4°C overnight for solidification. Then the tubes were imaged with an eight-channel phased-array head coil on a 3.0-Tesla MR scanner (Siemens, Germany). Spin Echo T2-weighted (SE T2WI) images were taken (repetition time [T_R] = 4,000 ms, echo time [T_E] = 89 ms, flip angle = 120, field of view [FOV] = 150 × 150 mm², slice thickness = 4 mm, Mat: 256 × 256).

Whole‐brain MRI was conducted using a customized Siemens 3.0 Tesla MR Scanner at Washington University. A 32‐channel head coil was used for radio frequency transmission and reception. A high‐resolution T1‐weighted anatomical image was acquired with gradient echo sequence: field of view =224 mm, voxel size = 0.7 × 0.7 × 0.7 mm, slice thickness = 0.9 mm, repetition time = 2400 ms, echo time = 2.14 ms, inversion time = 1000 ms, flip angle = 8°, and duration = 7:40 min (Van Essen et al., 2012).