Vnmrj 3.1 console

MR Images were acquired on a 9.4 T horizontal bore Varian system equipped with an Agilent VnmrJ 3.1 console. A custom made volumetric birdcage quadrature coil (Virtumed LLC) achieving a two channel (0° and 90°) radiofrequency (RF) power input of up to 55 μT/5 sec with an internal diameter of 36 mm and effective length of 25 mm designed to achieve a high B1 homogeneity was used for all imaging.

Images were collected on a magnetic resonance spectrometer tuned to 200.6 MHz proton resonant frequency (4.7 Tesla/33 cm actively shielded magnet). The MR system was equipped with Resonance Research Inc. spatial encoding gradients (RRI BFG-200/115-S14, maximum gradient strength of 670 mT/m at 300 Amps and a 120 μs risetime; RRI, Billerica, MA) and controlled by a VnmrJ 3.1 console (Agilent, Palo Alto, CA). A custom-built 8.8 cm x 11.6 cm radiofrequency (RF) transmit coil used in combination with a 3 cm x 3.5 cm actively decoupled/tunable RF receive quadrature surface coil (RF engineering lab, Advanced Magnetic Resonance Imaging and Spectroscopy Facility, Gainesville, FL).

On day 7 for the dose–response experiment cohort and on day 28 for the long‐term experiment cohort, rats were taken to the University of Florida's Advanced Magnetic Resonance Imaging and Spectroscopy Facility (AMRIS) for MRI. During imaging, rats were anesthetized under 1.5% isoflurane gas, placed in a body tube cradle, and setup in a surface transmit/receive radio frequency coil system used for high‐resolution imaging on a Magnex Scientific 4.7 Tesla MR scanner. T2 relaxometry pulse sequences were run on a VnmrJ 3.1 console (Agilent, Palo Alto, CA, USA). Core body temperature and respiratory rates were monitored throughout the experiments. For T2 relaxation, the following parameters were used: echo time (TE) = 37.5 ms, repetition time (TR)  = 2000 ms, target b value = 1269.92 s/mm², field of view 25.6 mm² along the read and phase directions and 1.5 mm along the slice direction, and data matrix of 96 × 96 × 8 slices. Signal averaging was used to increase signal to noise.
Images were imported to ImageJ for processing of T2 maps. T2 maps were reconstructed from a log linear regression of the multi‐TE value datasets. Infarct volume was measured by an investigator blinded to treatment conditions in the same manner described above. In T2 images, the area of infarct appears lighter than healthy tissue due to the extra free water content from edema.