1. Preserving Hyperpolarization of 129 Xe for Transport Zach Zytner Project Supervisor: Giles Santyr Medical Biophysics 3970 March 23, 2011

2. Introduction MR imaging with hyperpolarized noble gases – Greater resolution in lung imaging without harmful radiation – Effectiveness depends on nuclei high-spin polarization achieved outside system Preserving the 129 Xe polarization permits transporting the HNG to other research sites

3. Transportation Box Solenoid coil 12V NiMH Battery Glass vial Current control Current display (mA) Power switch Recharging terminal Solenoid coil (ID 15.3cm) Power supply (battery - 1650mA)

4. Method I: Project Layout Xe sample Solenoid coil Sustainability of battery Collection of polarized Xe Signal data at time intervals through polarimetry Determination of box’s T 1

5. Method II: Mapping the Field with Current Maximum current = 1650 mA Maximum field = 36.5 G (3.65 mT)

6. Method III: Characterizing Field vs. Time 18 hour charge shows rapid decay of field Best charging time shows box can maintain magnetic field

7. Polarimetry Station Helmholtz Coil RF coilStage for gas sample Pulse and response frequencies within 50Hz for accurate measurement of signal

8. Longitudinal Spin Relaxation Optical pumping of Rb followed by spin exchange with Xe nucleus Longitudinal relaxation time (T1) is the time taken to return to equilibrium within the lattice after an RF pulse excitation

9. Results I: Signal for 90mL Xe bag at t = 2 mins

10. Results II: Signal for 90mL Xe bag at t = 122 mins

11. Results III: Response Amplitude from Excel Trend Lines vs. Time Extrapolated signal @ t = 0 is 27.5mV Signal = 5.37 mV at 122 mins

12. Results IV: Response Amplitude from Polarimetry Software Trend Lines vs. Time Extrapolated signal @ t = 0 is 43.1 mV Signal = 2 mV at 122 mins

13. Results V: T 1 Determination Signal from Excel trend lines T 1 = 75 mins = 1.25 hrs Signal from polarimetry software trend lines T 1 = 40 mins = 0.67 hrs

14. Discussion With the current battery, transportation box must be charged more than 24 hours to maintain a sustainable magnetic field Signals obtained from the station is contaminated with noise With the current signals at ~ t = 0, T 1 found to be 40-75 minutes

15. Conclusions The transportation box could likely preserve hyperpolarization in 129 Xe if travelling short distances Recommendation: use battery with long life with short charging time

16. Acknowledgements Giles Santyr Adam Farag Mathieu Boudreau Alexei Ouriadov Matthew Fox Marcus Couch Julie Tanguay Ian Gerard Elaine Hegarty Funding: