Oral 23rd International Society of Magnetic Resonance Conference 2023

Development of hyperpolarized noble gas MRI methodology for health care and chemical engineering. (#42)

Thomas Meersmann 1 , Arthur Harrison 1 , Max Filkins 2 , Sean B Rigby 2 , Galina E Pavlovskaya 1
  1. Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom
  2. Sir Peter Mansfield Imaging Centre, Department of Chemical Engineering, University of Nottingham, Nottingham, United Kingdom

Over the last two decades, hyperpolarized noble gasses (hpNG) have emerged as contrast agents for functional and microstructural MRI of lungs in health and disease. Utilizing the advances in high power diode array lasers, these contrast agents are typically generated via spin exchange optical pumping (SEOP). Compared to the 129Xe thermal equilibrium signal at common clinical pulmonary MRI field strengths of 1.5 – 3 Tesla, the methodology allows for a signal enhancement of 4 – 5 orders of magnitude [1].

As a new modality, our group has introduced hyperpolarized nuclear spin I = 9/2 noble gas isotope 83Kr as MRI contrast agent to probe surface to volume ratios in lungs and materials. The surface quadrupolar relaxation (SQUARE) of 83Kr is a potential biomarker for emphysema and potentially for lung diseases that alter the chemical composition of the lung surfactant layer [2]. However, as a consequence of quadrupolar relaxation, hp 83Kr cannot be concentrated from the buffer gases of the laser pumping process through cryogenic separation without depolarization. Therefore, a new production methodology was developed that uses molecular hydrogen as buffer gas during SEOP followed by its subsequent removal through catalytic combustion [3]. Remarkably, the generated hyperpolarized state, that corresponds to a very low spin temperature of < 0.1 K, survives the high reaction temperature (> 1500 K).

We developed a computer-controlled ‘combustion system’ with a two stage reaction utilizing spark plug ignition and catalytic combustion for the purification of hp83Kr gas within a time span of 15s without significant losses to the krypton polarisation. A modification of this system also encompasses cryogen free hp129Xe production, and current improvements focus on more efficient hp gas recompression to ambient pressures and increased production volume to facilitate future clinical applications.

Similarly, the robustness of the hyperpolarized state can also be applied to establish the structure-transport relationship in chemical engineering and related fields. For example, gas transport and reactive zones in diesel catalysts, that consist of hierarchical porous solids with ordered and disordered levels in the hierarchy have been explored [4, 5].

  1. [1] D. M. L. Lilburn, G. E. Pavlovskaya, T. Meersmann, J. Magn. Reson. 2013, 229, 173-186.
  2. [2] D. M. L. Lilburn, A. L. Tatler, J. S. Six, C. Lesbats, A. Habgood, J. Porte, T. Hughes-Riley, D. E. Shaw, G. Jenkins, T. Meersmann, Magn. Reson. Med. 2016, 76, 1224-1235
  3. [3] N. J. Rogers, F. Hill-Casey, K. F. Stupic, J. S. Six, C. Lesbats, S. P. Rigby, J. Fraissard, G. E. Pavlovskaya, T. Meersmann, P. Natl. Acad. Sci. USA 2016, 113, 3164-3168.
  4. [4] D. B. Burueva, E. V. Pokochueva, X. P. Wang, M. Filkins, A. Svyatova, S. P. Rigby, C. B. Wang, G. E. Pavlovskaya, K. V. Kovtunov, T. Meersmann, I. V. Koptyug, ACS Catal. 2020,
  5. [5] F. Hill-Casey, T. Hotchkiss, K. A. Hardstone, I. Hitchcock, V. Novak, C. M. Schlepütz, T. Meersmann, G. E. Pavlovskaya, S. P. Rigby, Chem. Eng. J. 2021, 405, 126750