TY - JOUR

T1 - Pilot multi-site quality assurance study of batch-mode clinical-scale automated xenon-129 hyperpolarizers

AU - Birchall, Jonathan R.

AU - Irwin, Robert K.

AU - Nikolaou, Panayiotis

AU - Pokochueva, Ekaterina V.

AU - Kovtunov, Kirill V.

AU - Koptyug, Igor V.

AU - Barlow, Michael J.

AU - Goodson, Boyd M.

AU - Chekmenev, Eduard Y.

N1 - Copyright © 2020 Elsevier Inc. All rights reserved.

PY - 2020/7

Y1 - 2020/7

N2 - We present a pilot quality assurance (QA) study of spin-exchange optical pumping (SEOP) performed on two nearly identical second-generation (GEN-2) automated batch-mode clinical-scale 129Xe hyperpolarizers, each utilizing a convective forced air oven, high-power (~170 W) continuous pump laser irradiation, and xenon-rich gas mixtures (~1.30 atm partial pressure). In one study, the repeatability of SEOP in a 1000 Torr Xe/900 Torr N2/100 Torr 4He (2000 Torr total pressure) gas mixture is evaluated over the course of ~700 gas loading cycles, with negligible decrease in performance during the first ~200 cycles, and with high 129Xe polarization levels (avg. %PXe = 71.7% with standard deviation σPXe = 1.5%), build-up rates (avg. γSEOP = 0.019 min−1 with standard deviation σγ = 0.003 min−1) and polarization lifetimes (avg. T1 = 90.5 min with standard deviation σT = 10.3 min) reported at moderate oven temperature of ~70 °C. Although the SEOP cell in this study exhibited a detectable performance decrease after 400 cycles, the cell continued to produce potentially useable HP 129Xe with %PXe = 42.3 ± 0.6% even after nearly 700 refill cycles. The possibility of “regenerating” “dormant” (i.e., not used for an extended period of time) SEOP cells using repeated temperature cycling methods to recover %PXe is also demonstrated. The quality and consistency of results show significant promise for translation to clinical-scale production of hyperpolarized 129Xe contrast agents for imaging and bio-sensing applications.

AB - We present a pilot quality assurance (QA) study of spin-exchange optical pumping (SEOP) performed on two nearly identical second-generation (GEN-2) automated batch-mode clinical-scale 129Xe hyperpolarizers, each utilizing a convective forced air oven, high-power (~170 W) continuous pump laser irradiation, and xenon-rich gas mixtures (~1.30 atm partial pressure). In one study, the repeatability of SEOP in a 1000 Torr Xe/900 Torr N2/100 Torr 4He (2000 Torr total pressure) gas mixture is evaluated over the course of ~700 gas loading cycles, with negligible decrease in performance during the first ~200 cycles, and with high 129Xe polarization levels (avg. %PXe = 71.7% with standard deviation σPXe = 1.5%), build-up rates (avg. γSEOP = 0.019 min−1 with standard deviation σγ = 0.003 min−1) and polarization lifetimes (avg. T1 = 90.5 min with standard deviation σT = 10.3 min) reported at moderate oven temperature of ~70 °C. Although the SEOP cell in this study exhibited a detectable performance decrease after 400 cycles, the cell continued to produce potentially useable HP 129Xe with %PXe = 42.3 ± 0.6% even after nearly 700 refill cycles. The possibility of “regenerating” “dormant” (i.e., not used for an extended period of time) SEOP cells using repeated temperature cycling methods to recover %PXe is also demonstrated. The quality and consistency of results show significant promise for translation to clinical-scale production of hyperpolarized 129Xe contrast agents for imaging and bio-sensing applications.

KW - Automation

KW - Hyperpolarization

KW - Hyperpolarizer

KW - Quality assurance

KW - SEOP

KW - Xenon

KW - XENON POLARIZATION

KW - MRI

KW - LASER-DIODE ARRAYS

KW - SPIN-POLARIZED XE-129

KW - NMR

KW - SPECTROSCOPY

KW - MAGNETIC-RESONANCE

KW - GAS

KW - PERFUSION

KW - EXCHANGE

UR - http://www.scopus.com/inward/record.url?scp=85085987787&partnerID=8YFLogxK

U2 - 10.1016/j.jmr.2020.106755

DO - 10.1016/j.jmr.2020.106755

M3 - Article

C2 - 32512397

AN - SCOPUS:85085987787

VL - 316

SP - 106755

JO - Journal of Magnetic Resonance

JF - Journal of Magnetic Resonance

SN - 1090-7807

M1 - 106755

ER -