Table 3. Factors in animal handling that may affect the obtained MRI data and their variation across sites.

Animal temperature was monitored and adjusted throughout the scan session by adjusting the water circulation heating of the holder. Range of temperatures recorded during the diffusion weighted imaging (DWI) are shown. Respiratory rate was monitored by pressure sensor and maintained constant by adjusting the isoflurane. Respiratory rate during the scan session was generally stable in each animal, but varied between animals. Range of respiratory rates at each site are shown, as are the range isoflurane levels. Carrier gar was identical in all sites (30% O2 / 70% N2). Ranges are comparable across sites. Total anesthesia durations are shown as mean ± std, and they are similar across sites despite the fact that at UEF a blood sample was drawn after the anesthesia induction. Anesthesia duration before the scan onset (anesthesia prior scan) consists of induction (5% isoflurane in chamber), blood sampling, and setting up animal on the holder. Holder setup was similar across sites. Scan execution order was designed to their sensitivity towards effects of blood CO2 levels on T2* relaxation, and effects of body temperature on diffusion. Similar scan execution order was instructed to all sites. Occasional deviations from the order have not been analyzed.

Animal physiology	UEF	Melbourne	UCLA
Body temperature	36.5–37.6 °C	36.0–37.0 °C	36.0–37.0 °C
Respiratory rate: maintained range (brief deviations: min-max)	48–70bpm (45 – 80bpm)	50–65bpm (45 – 80bpm)	45–60bpm (40–80bpm)
Anesthesia duration	1h 47 min ± 12 min	1h 45 min ± 9 min	1h 45 min ± 5 min
isoflurane level	1.3–2.0%	1.5–2.0%	1.5–2.0%
anesthesia duration prior scan induction/blood sampling/setup	5min/5 – 10 min/5min	5min/ – /5min	5min/ – /5min