Magnetom skyra 3t mr scanner

The minipigs were kept anesthetic as described above. The MAGNETOM Skyra 3T MR Scanner (Siemens, Erlangen, Germany) was used to scan the cardio-MRI for assaying the left ventricular function, including ejection fraction, left ventricular end-systolic and diastolic volume, stroke volume, cardiac output, and wall mass. The MRI special nonmagnet ECG electrodes were placed on the chest. Four electrodes were placed on left medioclavicular line of the second and fifth intercostal space and on the left border of sternum of the second and fifth intercostal space separately.
Fix the position of two-chamber, four-chamber, and short-axis by using Turbo FLASH (TFL) sequence. Under this position, the T1 weight imaging (T1WI) and T2 weight imaging (T2WI) of the turbo spin echo (TSE) sequence were scanned for the anatomical structure of heart. The parameter was TR = 800 ms, TE = 71 ms, FOV = 340 mm × 276 mm, slice thickness = 5 mm, slice distance = 2.5 mm, and FA = 180 degrees. Cine scanning was performed in short axis, two-chamber, and four chamber position, and the parameter was TR = 39.24 ms, TE = 1.43 ms, FOV = 340 mm × 285 mm, FA = 65 degrees, slice thickness = 6 mm, slice distance = 1.2 mm, slice 1, and phase encoding: A-P, segments = 15. The movement of heart and heart function were tested under this sequence.

All data were collected on an MAGNETOM Skyra 3 T MR scanner (Siemens, Erlangen, Germany) using a 20-channel head-neck coil. The MRI exam consisted of multi-TI ASL, T1 MPRAGE, and 3D fast spin-echo double inversion recovery sequence (SPACE-DIR). Multi-TI ASL images were acquired with a background-suppressed 3D GRASE PASL sequence with the following parameters: TR/TE = 4,600/22 ms, FOV = 220 mm × 220 mm, slice thickness = 4 mm, voxel size = 3.4 mm × 3.4 mm × 4.0 mm, 36 slices, bolus length = 700 ms, 16 TIs from 480 to 4,080 ms with a step of 225 ms, and total acquisition time = 5:09 min including an M0 scan. The CBF, BAT, and residual error maps were calculated in-line on the scanner using vendor software. MPRAGE was acquired in a sagittal orientation with 1 mm isotropic resolution (FOV = 230 mm × 230 mm, 192 slices, TR/TE = 1,900 ms/2.58 ms, TI = 900 ms, flip angle = 9°) in 4:59 min. The imaging parameters for SPACE-DIR were: TR/TE = 7,500/319 ms, 144 slices, slice thickness = 1.4 mm, FOV = 230 mm × 230 mm, matrix size = 192 × 192, IR-Delays 450/3,000 ms, total acquisition time = 6:17 min. All participants wore earplugs, and their heads were immobilized with a vacuum bean bag pillow, padded earmuffs, and a plastic bar across the bridge of the nose.

Magnetic resonance imaging data were acquired using a MAGNETOM Skyra 3T MR scanner (Siemens Healthcare, Erlangen, Germany) with 64 channel head coils. Smokers were required to smoke a cigarette 30 min before the scan to avoid nicotine withdrawal symptoms. During the scanning, each participant was asked to close their eyes, not to think of anything special, breathe quietly, and avoid falling asleep. At the end of the scan, the subjects were asked if they had fallen asleep, and those who had fallen asleep were eliminated. We used foam pads and earplugs to minimize head movement and canner noise. The following echo planar imaging parameters were used to acquire functional images: repetition time (TR)/echo time = 2,000/30 ms, matrix size = 64 × 64, flip angle = 80°, field of view = 240 × 240 mm, voxel size = 3 mm × 3 mm × 3 mm, slices = 36, slice thickness = 4 mm, and 180 volumes in total.