Hyperpolarized 3-helium MR imaging of the lungs: testing the concept of a central production facility

Abstract

The aim of this study was to test the feasibility of a central production facility with distribution network for implementation of hyperpolarized 3-helium MRI. The 3-helium was hyperpolarized to 50-65% using a large-scale production facility based at a university in Germany. Using a specially designed transport box, containing a permanent low-field shielded magnet and dedicated iron-free glass cells, the hyperpolarized 3-helium gas was transported via airfreight to a university in the UK. At this location, the gas was used to perform in vivo MR experiments in normal volunteers and patients with chronic obstructive lung diseases. Following initial tests, the transport (road-air-road cargo) was successfully arranged on six occasions (approximately once per month). The duration of transport to imaging averaged 18 h (range 16-20 h), which was due mainly to organizational issues such as working times and flight connections. During the course of the project, polarization at imaging increased from 20% to more than 30%. A total of 4 healthy volunteers and 8 patients with chronic obstructive pulmonary disease were imaged. The feasibility of a central production facility for hyperpolarized 3-helium was demonstrated. This should enable a wider distribution of gas for this novel technology without the need for local start-up costs.

Design and evaluation of a 32‐channel phased‐array coil for lung imaging with hyperpolarized 3‐helium

“…All human experiment procedures were approved by the local ethics committee. The imaging experiments used a CE-certified polarizer (Institute of Physics, Johannes Gutenberg University, Mainz, Germany) for preparing hyperpolarized 3 He with a polarization of 65-70% (24). All scans were run with the same healthy volunteer to facilitate comparison of the performance of the two coils.…”

Large Production System for Hyperpolarized 129Xe for Human Lung Imaging Studies

“…3 He in the gas state has a T 1 relaxation time that can reach days and even weeks [6,7]. As a beneficial consequence, 3 He can be distributed from a central polarizing site to MRI centers [8]. Practical limitations of MRI studies involving 3 He include its confinement to the lung gas space only, since its solubility in blood and tissue is extremely low [12].…”

Magnetic Resonance Imaging: From Spin Physics to Medical Diagnosis

“…Mechanical compression attempts resumed only after the first multi-watt lasers for MEOP have been developed in the late 1980s [63], this time succeeding in reaching sufficient polarization and pressure for use in various experiments [64,65], in particular to prepare polarized 3 He targets for the measurement of the neutron electric form factor in scattering experiments of polarized electron beams [66]. Since then, various non-relaxing mechanical compression techniques have been applied to polarized 3 He, using a diaphragm pump [67], a peristaltic pump [68], or a piston compressor [69,70] for applications in lung MRI, in more accurate electron scattering experiments, and in neutron spin filters [71,72].…”

“…Commercially available fiber lasers 9 deliver up to 15 W. The optimized large-scale system currently in operation at Mainz University, that is used to produce polarized gas for lung MRI, for scattering experiments and for neutron spin filters, makes use of five OP cells, each one being over 2 m-long, to efficiently absorb as much as possible of the available pumping power [70]. With the high quantum efficiency of MEOP, this system routinely yields 1.2 bar×liter/hour of 80%-polarized 3 He, or 3.3 bar×litre/hour of 60%-polarized 3 He [70]. To date, systems with similar performance operate only at the ILL in Grenoble [69] and in Garching 10 for neutron spin filters.…”

“…Storage cells suitable for transportation, i.e. with very long relaxation times and magnetic shielding to avoid loss of polarization, have been developed, and shipping of hundreds of liters of polarized gas has now been successfully performed [70]. More compact systems, in which cell size, laser power, and compressor flow rate are all consistently lower, have of course a significantly reduced performance, yielding e.g.…”