Magnetom avanto mri system

Images were acquired on a 1.5 T Siemens Magnetom Avanto MRI system (Siemens, Erlangen, Germany). A high-resolution structural image was created using a T1-weighted sequence (TR = 2.25 s, TE = 2.95 ms, 1 × 1 × 1 mm in-plane resolution). Functional images were acquired using a 2D EPI sequence (TR = 2.02 s, TE = 40 ms, 3 × 3 × 3.5 mm, 26 sagittal slices). Data were pre-processed using SPM8 (Wellcome Trust Centre for Neuroimaging, London, UK). We discarded the first four volumes of every run in order to allow for initial equilibrium. Functional images were first spatially realigned to the mean and then corrected for slice timing. The mean functional image was brought in register with the T1. The T1 was furthermore segmented using SPM8’s segment function, which yielded normalization parameters into MNI space. Finally, functional images were normalized into MNI space, and smoothed (6 × 6 × 6 mm FWHM).

MRI was performed on days 1 and 84 post-MCAO on a Siemens 3.0 Tesla Magnetom Avanto MRI system. Utilizing the previously described surgical anesthesia protocol [35 (link)], MRI of the cranium was performed using a 12-channel head coil, 25 cm in diameter, with the pig positioned in supine recumbency. Standard multiplanar magnetic resonance (MR) brain imaging sequences were acquired including T2FLAIR, T2W, DWI, and DTI. T2FLAIR, T2W, DWI, and ADC maps were analyzed using Osirix software (version 5.8.5, Pixme, Geneva, Switzerland). DTI and computed FA values were analyzed using ImageJ software. Analysis of MLS was performed by two trained blinded independent raters on coronal and axial planes on T2-weighted MR images at the level of the septum pellucidum. To determine inter-rater reliability, Pearson’s correlation was conducted on MLS measurements in axial and coronal planes by two raters in both NSC EV–treated and non-treated animals. Pearson’s correlation of raters’ measurements showed a NSC EV axial of R² = 0.679 (p = 0.0228), NSC EV coronal of R² = 0.841 (p = 0.0036), non-treated axial of R² = 0.970 (p < 0.0001), and non-treated coronal of R² 0.936 (p < 0.001) indicating that their measurements were significantly related. Average MLS values of both raters per animal were utilized for all correlation analysis.

MRI (T1- and T2-weighed imaging) scans were obtained within the 4–7 days after birth [34 (link)–36 (link)] when the vital sign of the children was relatively stable. All infants were scanned with a 1.5-T Magnetom Avanto MRI system (Siemens, Erlangen, Germany), including MRI plain0 T1WI and T2WI scans. T1WI sequence parameters: RF pulse repetition time 585 ms, echo time 15 ms. T2WI sequence parameters: RF pulse repetition time 4000 ms, echo time 102 ms, a layer thickness of 4 mm, layer spacing of 0.4 mm, and field of view of 20 × 20 cm. All MRIs in this study were read independently by two radiologists who specialized in neuroimaging, and they discussed their findings together. The basal ganglia/watershed scores were determined as proposed by Barkovich et al. [37 (link)]: 0 = no abnormalities in the basal ganglia or cortex; 1 = an abnormal signal in the basal ganglia or thalamus; 2 = an abnormal signal in the cortex; 3 = an abnormal signal in the cortex and basal nuclei (basal ganglia or thalami); 4 = an abnormal signal in the entire cortex and basal nuclei. All images and qualitative scores were assessed by an experienced radiologist, who was blinded to the serum NSE levels and clinical data.