Rats were placed prone in a cradle under the general anesthesia with an inhalation of isoflurane (1%~2.5%). The rat’s head was fixed using ear bars and a tooth bar. Body temperature was maintained between 35.3 and 37.3 °C by a flow of warm air using a heater system.
MR measurements were conducted on a 7-T preclinical scanner (BioSpec 70/20 USR, Bruker BioSpin MRI GmbH, Ettlingen, Germany) with a quadrature transmit-receive volume coil to detect MRI signals (inner diameter 72 mm, #T9562, Bruker BioSpin). MRI data were then acquired with the dedicated operation software (ParaVision (version 5.1), Bruker BioSpin). To obtain morphological information on carotid arteries, three-dimensional time-of-flight MR angiography (MRA) was performed with the following acquisition parameters; flow compensated gradient echo pulse sequence, TR 30 msec, TE 2.52 msec, flip angle 40°, field of view (FOV) 32 × 32 × 16 mm3, acquisition matrix size 160 × 160 × 80, isotropic spatial resolution 200 µm, axial orientation, number of averages = 1, and scan time approximately 6.5 minutes.
MR measurements were conducted on a 7-T preclinical scanner (BioSpec 70/20 USR, Bruker BioSpin MRI GmbH, Ettlingen, Germany) with a quadrature transmit-receive volume coil to detect MRI signals (inner diameter 72 mm, #T9562, Bruker BioSpin). MRI data were then acquired with the dedicated operation software (ParaVision (version 5.1), Bruker BioSpin). To obtain morphological information on carotid arteries, three-dimensional time-of-flight MR angiography (MRA) was performed with the following acquisition parameters; flow compensated gradient echo pulse sequence, TR 30 msec, TE 2.52 msec, flip angle 40°, field of view (FOV) 32 × 32 × 16 mm3, acquisition matrix size 160 × 160 × 80, isotropic spatial resolution 200 µm, axial orientation, number of averages = 1, and scan time approximately 6.5 minutes.